Selective Space Structures Manual

Transcription

1 Selective Space Structures Manual February 2017

2 CONTENTS 1 Contents 1 Overview and Concept General Concept Modules The 3S Generator The Structure Cell Cell Size and Cell Grid Nodes Add Nodes Move Nodes Edit Nodes Bars Add Bars Move Bars Bar Options Profiles Add Hatches and Contours Edit Hatches and Contours Slice Options for Contours Assign Profiles to Bars Visualize Profiles Faces Add Faces Move Faces Edit Faces STL Elements

3 CONTENTS Add STL Element Move STL Elements Edit STL elements Cell Management and Information Transitions Add Transition Edit Transitions Transition Rules Insert Structures into Parts Volume Data The 3S Executor Fragmentation Rasterize Part Select Fragments Selection Options Viewing Options for Fragments General Viewing Options Hide and Show Fragments Fragment Names and Colors Fragment Management Split into Connected Fragments Select Grid Cells Merge Fragments Groups Delete Fragments Reset Fragmentation Enlarge Grid Cut Fragments Cut Box Free Cut Fragmentation Tools Create Skin Split Off Blocks

4 CONTENTS Create Chessboard Randomize Projection Expand Split by Environment Assign Structure Cells Preparation of the Structure for Production Create Simulation Export Structure as STL Slice Structure The Structure in the Slice Commander Example: Create Hollow Part with Interior Structure Example: Point Reduction Export Slice in machine-specific format S Scripts Add Scripts The LUA Script Language Basic LUA Orders Commands for the Script Module Script Examples Settings for Selective Space Structures 125 Index 126

5 GENERAL CONCEPT 4 Chapter 1 Overview and Concept 1.1 General Concept The Selective Space Structures (3S) module is part of the 3D-printing software netfabb Studio Professional and has been created to solve the highly difficult task of creating complex structures within parts. With help of a variety of intelligent applications and the principle of building repetitive structure cells, Selective Space Structures offer an elegant and well-thought solution to this problem, following the model of repetitive spatial lattice-structures in nature. The resulting structures combine stability, lightness and efficiency and can be applied in very diverse fields. With the structures, it is possible to assign different functional attributes to the same material, such as stability and lightness, flexibility, thermal conductivity and precise power absorption and distribution. With the 3S-software, 3D-files are converted into structures in three simple steps and without elaborate design processes. First, abstract representations of box-shaped structure cells are defined and created. Secondly, the part is gridded and the cells are multiplied within fragments of the part, whereas different fragments can be filled with different structure cells (figure 1.1). Finally, the fragments containing the structures are saved as 2 1/2-dimensional slice files ready for Additive manufacturing. This automatic and repetitive insertion of structure cells means that users do not have to construct whole structures manually, which would require very much time and experience and could cause high costs. Furthermore, as the three-dimensional structure cells are only created as abstract representations, which are converted directly

6 GENERAL CONCEPT 5 Figure 1.1: Left: Repetitive Structure cells created in netfabb. Right: A manufactured structure cube containing two different kinds of structure cells into a slice file, it is not necessary to create three-dimensional STL-files containing the structure. This avoids a huge amount of processing and saves calculation time, as two-and-a-half-dimensional slice files have a much smaller data volume and are much easier to handle than three-dimensional files. With help of scripts, the cell distribution can be automated, combining any number of cell types and fragments. These automation and scripting capabilities can be used to develop one-click-solutions, forming a complete development environment for structural generation and application techniques. Figure 1.2: A manufactured part with an interior structure and a solid outer wall

7 MODULES 6 Figure 1.3: A skeletal foot produced with different structures and materials 1.2 Modules In the 3S Generator, the structure is defined and structure cells are created. Cell ranges and descriptions can be adjusted and the cell geometry can be constructed from simple design elements such as nodes, bars and faces. For a more complicated cell geometry, STL-files can be imported into the cell. Transitions can be added to the cells to connect loose ends between neighboring cells. The solid part is gridded and fragmented with the 3S Executor. The fragments are groups of grid cells (or voxels) of the gridded part. The voxel resolution of the grid and the fragment sizes and arrangement can be defined differently for every structure. There are various ways to assign different sections of the part to different fragments (figure 1.4). After the fragmentation, you can insert different structures or solid cells into the different fragments. The structure cells are multiplied within the fragments and are arranged nexttogehter to form a connective structure. With this process, the structure is applied to the part. On the basis of this information, the structure is converted into slice files by the 3S Slice Preview. The 3S Slice Preview can export slice files in a number of formats, including.cli,.sli,.slc,.ssl,.abf,.clf,.cls and.usf. For complicated structural definitions, the 3S Script module can be used to predefine cells, fragmentation and structures. It is a very efficient tool for recurring tasks within

8 MODULES 7 Figure 1.4: Different fragments can be filled with different structure cells the Selective Space Structures module.

9 8 Chapter 2 The 3S Generator To create a new structure, double-click on the blue Plus-icon to the right of the Structure Library section in the project tree (figure 2.1), or right-click on that section and choose "Create New Structure" in the context menu. If you want to load an existing structure into your netfabb, you can either move them by drag & drop from your file browser window into your netfabb window, double-click on the folder icon next to the Structure Library or choose "Import New Structure" in the context menu or in the Structures menu. Similarly, you can also export and save structures in the Structures menu or in the context menu after right-clicking on the structure in the project tree. The file format for structures is.3spackage. Figure 2.1: Create New Structure A structure is always placed in the Structure Library in the project tree, with subdirectories for structure cells, profiles, input data and scripts. Elements of the structure are organized as other elements in the project tree (figure 2.2). Several organizational options for structures are available in the Structures menu (figure 2.3). You can create new structures, remove or duplicate the current structure, and you can save or load structures.

10 THE STRUCTURE CELL 9 Figure 2.2: A structure in the project tree Figure 2.3: The Structures Menu and the Cell Menu 2.1 The Structure Cell To apply structures to parts, you have to design a single structure cell which is going to be multiplied in the part. When you add a structure to your project, it will automatically include a first, empty cell. To add further cells, double-click on the blue Plus-icon next to the Cells directory in the project tree or choose Create New Cell in the context menu of that directory or in the Structures menu.

11 CELL SIZE AND CELL GRID 10 To open previously saved cells, there are four different ways: You can move them by drag & drop from your file browser window into your netfabb window, double-click on the little folder next to the Cells directory, right-click on the Cells directory and choose Import Cell in the context menu or choose Load cell in the Structures menu. Similarly, when you have created or edited a cell, you can also export and save it in the Cell menu (figure 2.3) or in the context menu after right-clicking on that particular cell in the project tree. The file format for structure cells is.3scell. To view and work on cells, simply click on them in the project tree. This will open the cell and add a Cell menu to the menu bar. Cells are composed of up to four kinds of elements: nodes, bars, faces and imported STL elements. In the toolbar, four different modes are available to add those elements. In the tabsheet, there is a register for each kind of element. The cell can be seen in the viewing screen. The viewing options in the cell screen are as in other netfabb modules, including the change of perspectives and the zoom functions. Also, as in the normal interface, you can select elements by a left-click or with help of a selection rectangle. The mode chosen in the toolbar determines which kind of elements can be selected. Selected elements are always marked green. 2.2 Cell Size and Cell Grid Select "Cell 1" in the project tree with a left-click. In the tabsheet, you can choose from the six registers Nodes, Bars, Faces, STL elements, Cell and Information (figure 2.4). First, click on the Cell register and enter the preferred size of the cell in the "New Size" fields (figure 2.5). The three fields represent the X-, Y- and Z-axes. You have to click on Change Size to implement the operation. Alternatively, you can scale the cell by a chosen factor along all three axes (implement by clicking on "Scale"). If you already have inserted elements into your cell, these will be only scaled together with the cell when you resize it with Scale. If you resize it by "Change Size", elements will remain where they are, independently from the new cell frame. It is not necessary that all cells of the structure have the same size. However, it is recommended that cells are created which have a common denominator along all three axes, so that they can be arranged properly without overlapping. It is also recommended to use this denominator as size for the grid cells in the Volume Data

12 CELL SIZE AND CELL GRID 11 Figure 2.4: The cell in the project tree (top) and the registers of the cell tabsheet (bottom) Figure 2.5: The cell register (see chapter 3.1). In the viewing screen, the cell walls are marked by a grid consisting of rectangular squares. The grid plays a vital role during the placing of elements in the cell, as

13 NODES 12 some ways of placing elements refer to the grid lines, independently from lengths and distances. At the bottom of the tabsheet (of every register) you can change the number of grid lines across the three axes (figure 2.6). If the box "Equal" is ticked, there will be an equal number of grids along all three axes. If it is not ticked, the grid can be adjusted to a much finer factor along selective axes, or, if the cell size is set differently along the three axes, the grid squares can be made quadratic again. The number of grid lines does not have any influence on the cell size (figure 2.7). Figure 2.6: Change the number of grid lines at the bottom of the tabsheet 2.3 Nodes Nodes are points in the cell which are necessary to add other elements to the cell. They are not included in the structure and will not be manufactured (except if you activate the option "Slice as Sphere, see below), but they function as end points for bars and faces Add Nodes There are two ways to place and position nodes in the cell: If you click on the "Add Nodes" icon in the toolbar or choose "Add Nodes" in the context menu of the screen, you can add nodes with your mouse. These nodes are always placed at the intersection of three grid lines. As you move the mouse over the cell, a line of potential nodes along a grid line is displayed. That line always starts at a back or bottom wall of the cell, as seen from the current perspective. Thus, it is always one of the three walls whose grid is displayed in the screen. The displayed line of nodes starts at the closest intersection of grid lines to the mouse cursor. It represents all possible nodes along the grid line leading into the cell from that intersection. If you left-click, the line of nodes will be

14 NODES 13 Figure 2.7: Cell with two grid lines and with five grid lines along the X-axis. The size of the cell remains the same.

15 NODES 14 frozen. Then, you can click on one of the nodes in the line and an actual node will be added at the respective coordinates. During this process, a little box specifies the current coordinates of the mouse cursor (figure 2.9). A second way to add nodes is the insertion of coordinates in the tabsheet. The fields for the coordinates along the three axes are at the top of the Node register. Here, you can insert coordinates which are not bound to the grid lines. A node is placed by a click on the "New" button (figure 2.8). Figure 2.8: Insert coordinates to add nodes anywhere in the cell Move Nodes To work with or edit nodes, activate the Select-mode by clicking on the "Select" icon in the toolbar and select them with mouse clicks or by dragging a selection rectangle with your mouse. To add nodes to the selection, hold Ctrl or Shift and click on the nodes. To remove nodes from the selection, hold Ctrl and click on selected nodes. To move existing nodes into other positions, there are again several ways. First, if the "Drag & Drop" box in the tabsheet is ticked, you can move selected nodes by drag & drop, similar to moving objects in the normal netfabb interface. Secondly, you can use the eight arrow buttons in the node register of the tabsheet to move selected nodes. These will always be moved along grid lines by the distance of one cross grid line. If the current position is between the grid lines, the node will end up between the next grid lines, shifted by one square. The direction you can move nodes here are left, right, up, down, backwards and forwards. The axes are assigned to the arrow buttons depending on the current per-

16 NODES 15 Figure 2.9: Insert nodes with the mouse: First move your mouse over the cell and place and anchor point for a line of potential nodes. Then, click on one node in that line. That way, any number of nodes can be added.

17 NODES 16 spective. Thirdly, after selecting a node, you can insert specific coordinates in the "Position" fields. The nodes are then moved into the respective position, as soon as you click on the "Place" button. This third option to move nodes only works as long as only one node is selected (figure 2.10). Figure 2.10: Insert coordinates to move nodes anywhere in the cell If you have already attached bars or faces to the nodes, and you move the respective nodes, the bars and faces will be moved with them and their geometry or direction changed accordingly. If the box "Enforce Cell Size" is ticked, you cannot move nodes out of the cell. If it is not ticked, they can be moved outwards and overlapping structure cells can be constructed. Whenever you tick or untick this box, it is switched accordingly for all registers of the tabsheet Edit Nodes Further options for nodes available via buttons in the Node register (figure 2.12) and in the Cell menu are: Remove: Selected nodes are removed from the cell. You can also remove selected nodes by pressing Delete or in the context menu after you right-click on them. Duplicate: Selected nodes are duplicated. The duplicates can be moved and used separately. Slice as Sphere: If you tick this box, all selected nodes will be part of the slice when you export the structure. Consequently, they become part of the structure and are no longer only end points for bars and faces. That way, you can prevent gaps between bars, which you often get when you have sharp angles between the bars. In the text field to the right, you can enter the radius of

18 NODES 17 the spheres in the slice. You can set this independently for every node, or for several nodes at once, if you select them all. At the beginning, the radius is the same you have set in the node radius below. In the screen, the nodes which are to be sliced as spheres are orange, if they are not selected, and red, if they are selected (figure 2.11). Figure 2.11: Left: The first (orange = not selected) and the second (red = selected) node from the left are sliced as spheres. Right: The slice preview of that cell. The first two nodes are included as sphere. At the third node, there is a gap between the two bars. Remove unused: All nodes not used for bars or faces are removed. Merge nodes: All nodes in same positions are merged, independent from the current selection. If both are connected to bars or surfaces, the new node will take over all of those connections. Align at Grid: All nodes in the cell are moved to the next crossing of three grid lines. The slider below determines the radius of all nodes. As nodes are not manufactured or included in the structure, this function exists only for displaying reasons. If you have thick bars or faces in your cell, it is possible that they overlap with your nodes. In that case, you may have to increase the node radius so that they become visible again, which can be important for selecting or moving nodes.

19 BARS Bars Figure 2.12: The node register in the tabsheet Bars are elements in the cell which will be materialized in the structure. They are straight beams in the cell, using nodes as their end coordinates, and form an integral part of structure cells. To be realized at production, a profile must be added to the bar Add Bars Bars can be added very simply after clicking on the "Add Bars" icon in the toolbar or after choosing "Add Bars" in the context menu of the screen. Just click on two nodes and a bar is inserted between those nodes. The first node you clicked on is marked green, indicating that the next click on a node will add a bar (figure 2.13).

20 BARS 19 Figure 2.13: Add a bar by clicking on two nodes Move Bars Whenever the Select-mode or the Add-bars-mode is activated by the icons in the toolbar, bars can be selected by left-clicks on the respective bars. To add bars to the selection, hold Shift or Ctrl and click on them. If you want to remove bars from the selection, hold Ctrl and click on them. Additionally, if the Add-bars-mode is activated, you can select several bars at once by dragging a selection rectangle. Selected bars can be moved by drag & drop in the same way as nodes, if the "Drag & Drop" box in the tabsheet is ticked. With the arrow buttons in the tabsheet, the bars will always be moved along grid lines by the distance of one cross grid line. If the current position is between the grid lines, the bar will end up between the next grid lines, shifted by one square. The direction you can move bars here are left, right, up, down, backwards and forwards. The axes are assigned to the arrow buttons depending on the current perspective. Whenever you move bars, all nodes attached those bars are moved with them. Consequently, all other elements connected to those nodes are moved as well, and their geometry and direction can be changed. If the box "Enforce Cell Size" is ticked, you cannot move bars out of the cell. If it is not ticked, they can be moved outwards and overlapping structure cells can be

21 BARS 20 Figure 2.14: The bar register in the tabsheet constructed. Whenever you tick or untick this box, it is switched accordingly for all registers of the tabsheet Bar Options Choose by Profile: If you click on the button "Choose by Profile", you can simultaneously select all bars with a certain profile or all bars with no profile. Rotation: Here, you can set an angle, by which the profile of the selected bar is rotated around its central point. This interacts with the slice options of the profile. Remove: If you click on this button or press the Delete key on your keyboard, all selected bars are removed from the cell. This function is also available in the context menu. Scale: With the scale values in the tabsheet, you can create conical bars. The two scale values stand for the relative diameter of the bar at the two ends. The first value is the end at the node where you clicked on first while creating the bar. With the scale 1, the bar has exactly the diameter as defined in the profile (figure 2.15).

22 PROFILES 21 Figure 2.15: Different scales for the two ends result in a conical bar. 2.5 Profiles For the bars, it is very important that they have a profile. A profile is the twodimensional cross-section of a bar. As long as no profile is assigned to bars, they only serve as preview and, just as the nodes, will not be included when slice files are created out of the structure. So, the profile determines the material realization of the bar. For profiles, there is a separate subdirectory in the project tree (figure 2.16). With the creation of the structure, one empty profile is automatically inserted. Further profiles can be added by double-clicking on the blue Plus-icon next to the directory, by clicking on the "Create Profile" button in the Bar register of the Cell s tabsheet or in the Structures menu. You can also import profiles with the file format.3sprofile into your structure. Just use drag & drop to pull the file from your browser window into your netfabb window, or open the file via double-click on the folder icon next to the Profiles directory or via the context menu after right-clicking on that directory. If you click on a profile in the tree, the viewing screen switches to a screen with a two-dimensional grid. It is similar to the screen of the Slice Commander, as profiles, just as slices, are two-dimensional. Additionally, a Profiles menu is added to the menu bar (figure 2.17). In the Profiles

23 PROFILES 22 Figure 2.16: Profiles in the project tree menu or in the context menus of the project tree, you can remove, duplicate or export and save the current profile. You can also switch to the profile of a bar by double-clicking on the bar in the screen Add Hatches and Contours A profile consists of one or more hatches and/or contours. In the toolbar, you can choose to add either hatches or contours. In the tabsheet (figure 2.17), you can edit the contour s name, slice options, layer count, mark the slice contour as hatch and you can view information on your contours and hatches. Figure 2.17: Profile menu and tabsheet of profile screen

24 PROFILES 23 Add Hatches: Hatches are simple lines. In a bar, they are expanded to twodimensional surfaces. You can combine any number of hatches to create any pattern. They are added by clicking anywhere on the screen. The first click marks one end point of the hatch. Then, when you move the mouse across the screen, a preview of the hatch is shown. Another click inserts the second end point of the hatch and connects those ends. A right-click cancels the placing of the first end point. The end points are marked by little white boxes (figure 2.18). Figure 2.18: Two hatches Add Contours: Contours consist of several hatches which are connected at their end points. These endpoints thereby become corners. In contrast to end points, the corners are marked by a round dot. After the second corner is placed, a third click adds the next point of the contour. That way, any shape can be formed. A right-click ends the adding of points and the contour is finished (figure 2.19). If the option Close Contours Automatically is activated, the contour is automatically closed, when you click on the first point or very close to it. The first and last point are merged and become a corner and the contour is finished. Otherwise the points are not merged and you can continue shaping the contour. This function can be activated (default) or deactivated in the toolbar, in the context menu of the screen or in the Profiles menu. The area of closed contours is marked in a transparent blue.

25 PROFILES 24 Figure 2.19: A closed contour Create Standard Geometry: This function is available in the toolbar or in the context menu of the screen. It creates a regularly shaped, closed contour with equally scaled hatches and equal angles of the corners. In a dialog box, you can specify coordinates of the center of the contour, the diameter, the number of corners and an angle of rotation (clockwise) around its center. The contour is added by clicking on "Create" (figure 2.20). Figure 2.20: The dialog box for the creation of a standard geometry (left) and the resulting hexagon (right). Create Hollow Bars: If you want to create hollow bars instead of solid bars, you have to move a second, smaller closed contour into the first. If two contours are on top of each other, one is subtracted from the other. So, after placing a second contour into the first, only, the outer area around the inner contour remains blue and will

26 PROFILES 25 be realized in the bar. The inner contour can have any shape, independent from the shape of the outer contour (figure 2.21). Figure 2.21: Two contours for hollow bars. On the left, the inner contour is the same as the outer contour, only smaller. On the right, the inner contour has a different shape Edit Hatches and Contours Contours or free hatches are selected by clicking on any hatch. By holding Shift, you can add contours or hatches to the selection. By holding Ctrl, you can either add contours to or remove contours from the selection. When a contour is selected, its lines are coloured green. A green selection box frames all selected contours. Remove Contours: You can remove an entire contour by clicking on the red X in the toolbar, by pressing the Delete key or by choosing "Remove Contour" in the context menu. Move contour: Selected contours or hatches can either be moved freely by drag & drop, if you drag the central green box of the contour or the unhighlighted part of the outbox. You can also move a contour to specific coordinates, if you choose "Move" in the context menu or in the Profiles menu. In a dialog box, you can enter the preferred distance you want to move the contour along both axes or move the center of the contour back to the zero coordinates. Additionally, you can choose, if you want to move only the selected or all contours. If no contour or hatch is selected, the whole profile is moved. The contour is moved as soon as you click on "Move" (figure 2.22).

27 PROFILES 26 Figure 2.22: Left, the dialog box for moving a contour. Right, a contour is moved by drag & drop. Rotate Contours: The rotation of selected contours can be performed by clicking on the corners of the selection box, holding the left mouse button and dragging the corners around the contour. If you hold Ctrl, the contour is rotated in 10 steps. If you hold Shift, it is rotated in 45 steps. To insert exact specifications for a rotation, choose "Rotate" in the context menu or Profiles menu. Here, you fill in the coordinates which determine the point around which the contour is rotated. If you do not change these coordinates, the contour is rotated around the center of the whole profile. If you click on "Rotate around center point", the coordinates are corrected so that the contour is rotated around its own center. Then, you can insert the preferred angle of counter-clockwise rotation or choose a default angle. You can either rotate all or only selected contours. If no contour or hatch is selected, the whole profile is rotated. The rotation is performed as soon as you click on "Rotate" (figure 2.23). Scale Contours: You can scale selected contours or hatches by drag & drop, if you drag one of the highlighted central bars of the outbox inwards or outwards. When scaling by drag & drop, you can scale contours equally along the X- and Y-axes, if you hold Ctrl or Shift. With Ctrl, the center of the contour remains in the same position. With Shift, the opposite edge of the one you move remains in the same position. If you do not hold Ctrl or Shift, the scaling will be performed unequally, changing the proportions of the contour (figure 2.24). Alternatively, you can insert a scaling factor along the X- and Y-axes or mirror contours, if you choose "Scale" in the Profiles menu or in the context menu after

28 PROFILES 27 Figure 2.23: The dialog box for rotating a contour Figure 2.24: A Contour is scaled in X-direction right-clicking on the screen. You can either scale all or only selected contours. If no contour or hatch is selected, the whole profile is scaled. The mirroring is effectively a scaling by a negative factor. Click on "Scale" to conduct the operation (figure 2.25). Figure 2.25: The dialog box for scaling a contour by inserting scaling factors

29 PROFILES 28 Move Points: You can change the shape of contours and hatches by moving their points and corners. The hatches connected to those points are moved likewise. To move points, click on them and drag them into another position, holding the left mouse button (figure 2.26). Figure 2.26: The points of the contour can be moved by drag & drop Alternatively, if you right-click on a point and choose "Move point", a dialog box opens where you can insert specific distances in the X- and Y-direction, in which the point shall be moved. If the box "Relative" is ticked, the entered distance refers to the current position of the point, otherwise it refers to the zero coordinates (figure 2.27). Figure 2.27: Dialog box for moving points Merge Contours: Two end points of different contours are unified and become one corner. Thus, the two contours become one. Both contours have to be selected before they are merged. The function is available in the context menu, but works only, if two open points of the different contours are close together (figure 2.28).

30 PROFILES 29 Figure 2.28: The open points of two contours are merged Duplicate Contours: This function in the context menu creates duplicate contours of selected contours. Add point: If you right-click on or close to a hatch, you can choose the option "Add point" in the context menu. A corner is then added at the place you clicked, separating the original hatch (figure 2.29). Figure 2.29: A corner point is added to the contour Open Contour: If you right-click on a corner of a contour, and choose "Open contour" in the context menu, two end points replace the corner, separating the connection between the two adjacent hatches. The two points can then be moved separately (figure 2.30). Remove point: If you right-click on a point or corner and choose "Remove point" in the context menu, the point is removed. If you remove an end point, the hatch leading to this point is removed as well. If you remove a corner, the two adjacent hatches are replaced by a hatch connecting the two remaining, adjacent corners (figure 2.31).

31 PROFILES 30 Figure 2.30: A contour is opened. The opened points can be moved separately. Figure 2.31: A node is removed and the adjacent points are connected by a new hatch Close Contour: You can close open contours in the context menu, if you right-click on one of their hatches or points. The end points are either connected by a new hatch or, if they are very close together, they are merged (figure 2.32). Figure 2.32: With "Close Contour", open points are connected by a new hatch.

32 PROFILES 31 Close Contours Automatically: If the option "Close contours automatically" is activated (toolbar or context menu) and you move an open end point to another open end point of the same contour, they are merged automatically Slice Options for Contours In the tabsheet, you can insert a new name for the contour, change the way the profile is realized in the cell, mark the slice contour as hatch and you can view statistics about your contours and hatches. In the Slice Options, you have five ways to realize your profile. The effect of these options depend on the orientation of the bar. For exactly vertical bars, they do not make a difference (figure 2.33), but the closer the bar gets to a horizontal position, the more difference the slice options will make (figure 2.34, 2.35, 2.36): Figure 2.33: Parallel vertical bars: If bars are vertical, there is no difference between the three different slice options. 3D profile: The 3D profile is the default option. The profile is inserted in a right angle to the direction of the bar. So, the bar is realized similarly to a cylinder connecting the two nodes it is attached to, with your profile as cross section. Additionally, the top (+Y) of the profile is always oriented in direction of the Z-axis running through the lower node. Thus, the bar may rotate, if you move the nodes around these X-Y-coordinates. Flat profile: The profile is inserted horizontally as slice in the X-Y-plane. Those slices are then inserted to connect the nodes of the bar. Bars which are almost horizontal will get a very flat shape with this option. Cosinus projection: Again, horizontal slice-layers are inserted between the nodes of the bar. In contrast to the option "Flat profile", the profile is still inserted as cross

33 PROFILES 32 section of the bar. Thus, the slice has the same X-Y-cross section as the 3D-profile. However, at its ends, the bar is not cut off in a right angle to its direction, as is limited only by the Z-values of its nodes. All slice layers in between are inserted entirely. Flat profile with rotation: The bar is realized in the same way as with the option "Flat profile", with a rotation towards the Z-axis added, as in the 3D profile. Cosinus projection with rotation: The bar is realized in the same way as with the option "Cosinus Projection", with a rotation towards the Z-axis added, as the rotation in the 3D profile. Figure 2.34: Almost vertical bars: The difference becomes clear with flat bars. Figure 2.35: The cross section of the same flat bars: The cosinus projection has the same cross section as the 3D profile, while the bar "Flat profile" has almost no cross section at all. Minimum layer count: This is only relevant for very flat bars without the option 3D profile. It determines the minimum number of slice layers used for a bar. Slice Contour as Hatch: If this option is ticked, only the outer hatches of closed contours are realized. During production they are not filled.

34 PROFILES 33 Figure 2.36: The bar with 3D profile rotates towards the Z-axis Assign Profiles to Bars To assign a profile to one or more bars, select them and choose a profile in the dropdown menu in the Bar register of the Cell tabsheet. If you set a profile before you add bars, all bars will have this profile by default (figure 2.37 and 2.38). Alternatively, right-click on the bar(s), move your cursor over "Assign Profile" and choose a profile. The heading of the dropdown menu shows the profile of selected bars. If you have selected bars with different profiles, it will switch to "different profiles". Figure 2.37: The profile on the left is assigned to the bars. The bars are shaped with the profile as cross section.

35 FACES 34 Figure 2.38: The profile on the left is assigned to the bars. As there are four contours in the profile, there are four parallel bars Visualize Profiles If this box in the Bar register of the Cell tabsheet is ticked, the bars in the screen are displayed with their profile. Bars without profile are displayed in an orange color or, if selected, in red (figure 2.39). If the profiles are not visualized, they are displayed in blue as round cylinders. The thickness of this displayed cylinders can be altered in the "Bar Radius" slider below. This slider, however, does not have any influence on the profile or the real thickness of the bars (figure 2.40). 2.6 Faces Faces are plates inserted into the cell. One face is always attached to three nodes and therefore is triangular. To get faces with four or more corners, you must add more than one face, using the same nodes. This guarantees a connected plate Add Faces To add faces, click on the "Add Faces" icon in the toolbar or choose "Add Faces" in the context menu of the screen. Click on three nodes and a bar is inserted connecting those nodes. The first nodes you click on are marked green, the third click on a node will add a face (figure 2.41). Faces always have an orientation, which means they have a front and a back side. If

36 FACES 35 Figure 2.39: Left: The profiles of the bars are not visualized and a round bar is displayed. Right: The bars do not have any profiled and are displayed in orange. Figure 2.40: With this slider, the radius of the round bars can be adjusted, if the profiles are not visualized unselected, the front side is blue and the back side is purple. If you right-click on a face, all selected faces can be turned around with the option "Flip face" in the context menu (figure 2.42). You can also flip selected faces in the tabsheet Move Faces Whenever the Select-mode or the Add-faces-mode is activated by the respective icon in the toolbar, faces can be selected with left-clicks. To add faces to the selection, hold Shift or Ctrl and click on them. If you want to remove faces from the selection, hold Ctrl and click on them. Additionally, if the Add-faces-mode is activated, you can select several faces at once by dragging a selection rectangle.

37 FACES 36 Figure 2.41: Two faces are added to the bars and form one rectangular plate Figure 2.42: The front of the face is blue while the back side is purple Just as nodes and bars, faces can be moved by drag & drop, if the "Drag & Drop" box in the tabsheet is ticked (figure 2.43). With the arrow buttons in the tabsheet, the faces will always be moved along grid lines by the distance of one cross grid line. If the current position is between the grid lines, the face will again end up between grid lines, shifted by one square. The direction you can move faces here are left, right, up, down, backwards

38 FACES 37 and forwards. The axes are assigned to the arrow buttons depending on the current perspective. Whenever you move faces, all nodes attached to those faces are are moved with them, and consequently, all other elements connected to those nodes are moved as well, and their geometry and direction can be changed. If the box "Enforce Cell Size" is ticked, you cannot move faces out the cell. If it is not ticked, they can be moved outwards and overlapping structure cells can be constructed. Whenever you tick or untick this box, it is switched accordingly for all registers of the tabsheet. Figure 2.43: The Face register in the tabsheet Edit Faces In the Face register of the tabsheet, further options for editing selected faces are available (figure 2.43): Face Type: In the "Face Type" dropdown menu, you can choose between Prism and Flat. A flat face does not have any volume, while with a prism face, you can add thickness, offsets and edge overlap. The heading of the dropdown menu shows the face type of selected faces. If you have selected faces with different types, it will switch to "different face types".

39 FACES 38 Thickness: Here, you can enter the thickness for selected prism faces (figure 2.44). Figure 2.44: A thick prism face and a flat face Shift: With a shift, the face is moved away from the nodes it is attached to. If you enter a positive value, it is moved in the direction of the front side by that value. If you enter a negative value, it is moved in direction of the back side (figure 2.45). Figure 2.45: An offset of a face Edge overlap: With an edge overlap, a face overlaps the nodes it is attached to and exceeds the normal size. With a negative edge overlap, it does not reach the nodes and is smaller than the normal size. The default value is mm to guarantee that faces with a common edge (using the same nodes) are connected (figure 2.46). Remove: If you click on the "Remove" button or press the Delete key on your keyboard, selected faces are removed from the cell. You can also remove selected faces

40 STL ELEMENTS 39 Figure 2.46: A face with a positive (left) and a face with a negative edge overlap (right) in the context menu. 2.7 STL Elements Apart from that, you can also insert STL-files into a structure cell. These will be automatically scaled down to fit into the cell and can be an efficient alternative to bars and faces. It is recommended not to use too complicated parts, because the data volume will become hard to handle when a part is multiplied with the cell, and, as the STL-parts are usually scaled down significantly, no extreme details can be realized anyway Add STL Element To add STL elements to a cell, click either on the "Add STL" icon in the toolbar or on the "Add" button in the STL Elements register of the tabsheet Then, choose your file in the file browser (figure 2.47). The STL-file is then adapted to fit into the cell size and is inserted (figure 2.48). If the STL file you wish to insert is already a part your project, you can use your mouse to drag it from the parts section of the project tree into the cell Move STL Elements STL elements in the cell are selected and moved just as nodes, bars and faces: Whenever the Select-mode is activated in the toolbar, STL-elements can be selected by

41 STL ELEMENTS 40 Figure 2.47: Left: The STL elements tabsheet. Right: The file browser for adding STL files Figure 2.48: An STL file (Primitive Lattice with Hexagon Profile) is inserted into a cell left-clicks. To add STL elements to the selection, hold Shift or Ctrl and click on them. If you want to remove STL-elements from the selection, hold Ctrl and click on them.

42 STL ELEMENTS 41 They are then moved either by drag & drop, if the "Drag & Drop" box in the tabsheet is ticked, or by the arrow buttons in the tabsheet. With those, the STL elements are always moved along grid lines by the distance of one cross grid line. The direction you can move elements here are left, right, up, down, backwards and forwards. The axes are assigned to the arrow buttons depending on the current perspective. If the box "Enforce Cell Size" is ticked, you cannot move any elements out of the cell. If it is not ticked, they can be moved outwards and overlapping structure cells can be constructed. Whenever you tick or untick this box, it is switched accordingly for all registers of the tabsheet Edit STL elements The following options for editing STL elements are available either in the context menu, after right-clicking on the part, or in the STL register of the tabsheet. Scale STL Elements In a dialog box, the size of the original STL file, the current size and the current position are specified, and you can enter either the new size you want to scale the part to, or a scaling factor along all three axes. If you tick the box "equally", the STL element will be scaled by the same factor along all three axes. Thus, only the size of the element will be changed. If you scale the element unequally, the shape might change as well (figure 2.49). Rotate STL Elements This opens a dialog box where you can choose an axis around which the STL element will be rotated and insert an angle of rotation or choose a standard angle (figure 2.50). Further Handling Options for STL Elements Duplicate: This creates an exact copy of the STL element. Mirror: Here, you can choose an axis. The STL element is then mirrored in the direction of this axis, across the plane of the other two axes. Remove: Selected STL elements are removed from the cell. They can also be removed in the context menu or by pressing the Delete button.

43 CELL MANAGEMENT AND INFORMATION 42 Figure 2.49: The dialog box for scaling STL files Figure 2.50: The dialog box for rotating STL files 2.8 Cell Management and Information In the Cell menu or in the context menu after right-clicking on a cell in the project tree, you can remove the cell from your structure, create a duplicate of the cell or export the cell as 3s Structure cell. The function "Duplicate Cell" can be very useful, if you want to have rotated and mirrored copies of your cell. Export Cell as Part: If you move the cell per drag & drop from the structure library into the parts section of the project tree, the cell is inserted as three-dimensional part into the platform of your project. This gives you a three-dimensional preview of the cell and allows all part handling operations with the cell (figure 2.52). In the Cell menu, you can also save a cell as STL-file to your disc. Other options in the Cell register of the tabsheet are: Rotate and Mirror: The buttons for rotation on the left rotate the whole cell by 90

44 CELL MANAGEMENT AND INFORMATION 43 Figure 2.51: The STL element in this cell has been scaled to fit into the cell along two axes, rotated and moved into the center Figure 2.52: The cell on the left is moved into the platform where it can be used as any other part around the axis displayed on the icon. The mirror buttons on the right mirror the cell in the direction of the respective axis (figure 2.53). Enforce Cell Size: By ticking or unticking this box in the Cell register, the equivalent box is ticked or unticked in all registers of the tabsheet. If it is ticked, no elements

45 CELL MANAGEMENT AND INFORMATION 44 Figure 2.53: The buttons on the left rotate the cell. The buttons on the right mirror the cell in the direction of one of the three axes can be moved or placed out of the cell boundaries. If it is not ticked, overlapping structure cells can be created. Slice Preview: When you click on the "Slice Preview" button or choose "Slice Preview" in the Cell menu, you get a slice preview of the cell (figure 2.54). This preview is displayed like slices in the Slice Commander, although in the project tree, it is a subordinate element of the cell. You can move it as slice into the Slice Commander, where it is treated as any other slice file. Figure 2.54: The slice preview of a structure cell. In the information register (figure 2.55), you can add notes or descriptions about the cell and choose, if the cell shall be used as preview, when you edit your volume data or click on the structure or cells directory in the project tree. When you have clicked on the structure or the cells directory, you can change the tile at the bottom of the tabsheet, which determines how many cells are displayed along each axis (figure 2.56). Thus, you can see if your structure cell forms a coherent

46 CELL MANAGEMENT AND INFORMATION 45 Figure 2.55: The Information register in the tabsheet structure when it is inserted repeatedly. Only one cell can be used as preview at the same time. This box is automatically unticked, if you tick the equivalent box in the tabsheet of another cell. Figure 2.56: This preview of a structure show 3 cells along the X-axis, two cells along the Y-axis and one cell along the Z-axis.

47 TRANSITIONS Transitions Transitions are included into structure cells under certain conditions, depending on which structure cells are positioned next to them in the part. If the elements of two adjacent structure cells in the part do not meet and end up in empty space, you can insert additional elements to connect those loose ends. Figure 2.57: The bars of these two cells have different end points, resulting in loose ends, if they are placed nexttogether Add Transition In the 3S Generator, you can add a transition by clicking on the blue-plus-icon next to the cell in the project tree or in the context menu after a right-click on the screen of the cell or on the cell in the project tree (see figure 2.58). In the last case, you can also choose the option "Add standard transitions". If you do so, transitions with the names Back, Bottom, Front, Left, Right, Top are added (figure 2.59). These transitions can later be assigned for use in case certain other structure cells are positioned in the respective direction. When you have added a transition, it will be included into the project tree as subordinate element of the cell. It will be selected automatically, and every time a transition is selected in the project tree, the normal bars, faces and STL-elements of the cell will

48 TRANSITIONS 47 Figure 2.58: You can add a transition with a double-click on the blue plus (left) or in the context menu after clicking on the cell in the project tree (left) or on the screen (right). Figure 2.59: After a right-click on the cell in the project tree, you can also add standard transitions, as done here. be displayed transparently in the screen. Similarly, when the cell itself is selected, the elements of all transitions for which the little box in the project tree is ticked are displayed transparently Edit Transitions You can now add new elements for the transition in the same way as you add new elements to the normal cell (figure 2.60). Nodes you have inserted for the normal screen can be used for transitions and vice versa. Bars, faces and STL-elements of

49 TRANSITIONS 48 the transition are displayed normally. Figure 2.60: Here, bars have been added to the transition, which can connect the loose ends of the cells. The bars of the standard cell are displayed transparently. If you right-click on elements in the screen of either the cell or transitions, you can move them into other transitions or into the standard cell (Option "standard") in the context menu. It does not matter, if these elements are currently displayed solidly or transparently. If you want to rename or remove a transition, simply right-click on it in the project tree and choose the respective option in the context menu. If you move your mouse to "Duplicate", you have numerous options to create mirrored or rotated duplicates of the transition (figure 2.61). This is very helpful, when you have symmetric cells which require identical transitions in more than one direction, as you simply choose the direction of rotation for a duplicate and do not need to design the whole transition again Transition Rules To finally apply your transition to your structure in the part, click on the transition rules in the project tree and click on the button "Create New Rule" in the tabsheet (figure 2.62).

50 TRANSITIONS 49 Figure 2.61: When you duplicate a transition, you can rotate or mirror it in any direction. Figure 2.62: Click on "Create new rule" in the tabsheet to add a transition rule The viewing screen is then replaced by a screen in which all transition rules of that cell are listed (figure 2.63). Transition rules apply only for one structure cell. After

51 TRANSITIONS 50 you click on a rule in the list, you can alter it at the bottom of the netfabb window. Figure 2.63: Transition rules are listed in the screen In the dropdown menus at the bottom of the screen, the following options are available. Together, they form a sentence summarizing the transition rule: In the first field, you can enter the name of the transition rule. In the second field, there is a dropdown menu, where you can choose the geometric condition which determines, in which case the transition rule becomes active (figure 2.64). This geometric condition refers firstly to the direction and secondly either to the existence or the absence of a structure cell in that direction (Which structure cell is meant will be defined in the next step). If you choose "any cell is equal", the

52 TRANSITIONS 51 transition rule is activated, whenever that structure cell is a neighboring cell in any direction. Figure 2.64: Dropdown menu for the geometric condition In the third field, you define the structural condition of the transition rule by choosing a structure cell (figure 2.65). The transition rule becomes active when the cell you enter here is given in your part, combined with the geometric conditions. You can also choose "solid", "nothing" or "anything". Here, solid stands for adjacent solid fragment cells in the 3S Executor, nothing stands for open space and anything applies for any adjacent fragment. Figure 2.65: Dropdown menu for structural condition Next, you can set if the defined conditions shall activate or deactivate a transition. The last dropdown menu finally determines which transition shall be activated or deactivated by the transition rule. You can choose only transitions you designed for the cell the transition rule applies to. If you select "no transition", the transition rule may overrule other transition rules, as those either cannot be activated or cannot be

53 TRANSITIONS 52 Figure 2.66: Activate or deactivate a transition deactivated. If you select "all transitions", all transitions are activated or deactivated at once, if the defined conditions are given. Figure 2.67: Choose which transition is activated or deactivated by the transition rule With active transition rules, the transitions you have designed are finally inserted into your structure (figure 2.69). If you choose, for example, "If cell behind is equal", "Cell 4", "then activate" and "Transition 1", then your Transition 1 is activated and inserted into your structure cell every time the structure cell behind the current cell (the next cell towards positive Y-values) is Cell 4 (figure 2.68). Figure 2.68: Top: Transition rule for Cell 1. Bottom: Transition rule for Cell 4. They activate transitions for both cells, if Cell 4 is behind Cell 1

54 TRANSITIONS 53 Figure 2.69: A simulation of a structure with two different cells, seen from the top and from the left, and as slice preview of the structure. At the top, no transitions are included. At the bottom, transitions are added, connecting the fragments of the structure.

55 VOLUME DATA 54 Chapter 3 Insert Structures into Parts 3.1 Volume Data The volume data include some very important pre-settings for how a structure is realized in parts and contains important settings for the slicing of the structure. When you have designed your cell, open the Input Data directory in the project tree and click on Volume Data. One set of volume data is inserted automatically when you create a new structure (figure 3.1). New volume data can be added by a doubleclick on the Blue-Plus-icon next to the Input data directory, or in the context menu of the directory. Sets of volume data can also be removed in the context menu, or by double-clicking on the red-x-icon next to the respective volume data. Figure 3.1: The volume data in the project tree After you click on the volume data in the project tree, it can be edited in the tabsheet (figure 3.2). At the same time, a preview of one of your cells is displayed in the screen. In the Information tabsheet of the cells you can determine which cell is previewed. The Grid Size refers to the voxel resolution when parts are rasterized with the 3S executor (see chapter 4.1). The cells of the grid will have the size specified here

56 VOLUME DATA 55 Figure 3.2: The tabsheet for the volume data (figure 3.3). You will be able to insert your structure cells into these grid cells. It is not necessary to enter the same size as the size of your structure cells, but it is recommended not to choose a larger grid size then your smallest cell, and it is recommended to use a common denominator of all structure cells. Figure 3.3: The same fragmented part with large grid cells (left) and smaller grid cells (right)

57 VOLUME DATA 56 The standard cell will be inserted into fragments by default. You will be able, however, to change the cell for each single fragment. The layer size refers to the layer thickness, with which your structure is going to be sliced. The slicing process will convert the three-dimensional structure into a two-and-a-half-dimensional file. You will be able to change the layer size in the 3S Executor as well. Allow manual overwrite: You need to tick the box "Allow manual overwrite", if you want to be able to edit the cell assignment in the 3S Executor later on. If not, you will not be able to assign other structure cells manually. Rasterize automatically: If this box is ticked, the part is gridded automatically when you add the structure to the part. That means that all grid cells which are in touch with the part are filled with a basic fragment. This will enable you to conduct fragmentation operations or insert structure cells. You will also be able to rasterize the part later on, if the setting "Visible for User" is activated. Visible for user: Whenever this box is unticked, the volume data is not added to the project tree when the structure is applied to the part. It will still exist, but you will not be able to access and alter the volume data, the fragmentation or other specification in the 3S Executor. Cut with part contour: If this box is ticked and a slice preview is created, the structure is cut off at the boundaries of the original part. If it is not ticked, whole fragments are filled with the structure, even if they stand out of the part (figure 3.4). Volume group: You can add volume groups by clicking on the button "New Volume Group" in the tabsheet, by clicking on the Blue-Plus-icon next to the volume data or by opening a context menu in the empty field in the tabsheet and choosing "New Volume Group". Here, the volume groups will subsequently be listed. If you then right-click on a volume group in that list, you get a context menu where you can rename the volume group, remove it or assign cells to that group. If you choose "solid", no cell, but solid material will be assigned to the group. If you choose "free of choice", you will have to choose a cell in the 3S Executor. When you grid a part later on, the volume groups will be listed as subdirectories of the respective volume data directory of your part. You will be able to drag fragments into those subdirectories which will automatically be equipped with the cell you have specified here.

58 THE 3S EXECUTOR 57 Figure 3.4: Left: The slices of a part and of a structure. Center: The structure, as it will be produced without "Cut with part contour". Right, the structure with the option "Cut with part contour". The structure is only realized within the boundaries of the original part 3.2 The 3S Executor After you have finished your structure cell in the 3S generator, you can apply it to your part. Select the part in the Parts section of the project tree, click on the New Structure icon in the toolbar, or choose the option in the Extras menu or in the Extras submenu after right-clicking on the part. A list of structures appears, from which you can choose one. This is applied to the selected part. The structure will be added as subdirectory of the part in the project tree. It will contain directories for your volume data and volume groups (figure 3.5). After selecting elements in that directory, the functionality of the 3S Executor is available and the selective space structures are applied to a part.

59 THE 3S EXECUTOR 58 Figure 3.5: The applied structure is included in the project tree as subdirectory of the part

60 RASTERIZE PART 59 Chapter 4 Fragmentation 4.1 Rasterize Part Rasterizing the part is a necessary step to apply structure cells to the part. A threedimensional grid is placed around the part, dividing the part into box-shaped grid cells. The raster always has a cuboid shape, embraces the whole part and exceeds the part s size by one grid cell in every direction. A first basic fragment is inserted into the grid, consisting of all grid cells touching the actual part. If you have ticked the box "Rasterize automatically" in the volume data of your 3S Generator (chapter 3.1), the part is already rasterized and a gridded fragment is added to the project tree (figure 4.1). If you have added more than one set of volume data, you can create several different fragmented parts based on different information. In the screen, a transparent preview of the part is displayed. If you click on a volume data or a fragment in the project tree, the grid cells of the parts are added to this preview (The basic fragment is automatically called "Part" and contains the whole grid). If the part is not yet rasterized, click on the volume data in the 3S Executor and click on the Rasterize Part button in the tabsheet (figure 4.2), or right-click on the volume data or any subelement in the tree and choose "Rasterize part" in the context menu. The volume data of the 3S generator are used for the gridding. The grid cells which are in touch with the part become the first fragment. As the grid cells always have the shape of little boxes, they may stand out of the part (figure 4.3). This rasterization is based on the information in the volume data of the 3S Generator.

61 RASTERIZE PART 60 Figure 4.1: The basic fragment of a rasterized sphere, consisting of cubic grid cells Figure 4.2: Rasterize the part in the tabsheet. Therefore, the grid cells have the size specified there. This size of the grid cells is also referred to as voxel size or voxel resolution. So, at the beginning, the rasterized part consists of one big fragment. This fragment can be split into smaller fragments in several ways, enabling you to compose any partitioning. The fragments can then be filled with different structure cells to generate a very differentiated structured part. If you have already changed the fragmentation and click on "Rasterize Part", the rasterization of the part is renewed. Again, all grid cells in touch with the part are assigned to a new fragment called "Part". All changes to the fragmentation you have

62 SELECT FRAGMENTS 61 Figure 4.3: The grey line is the edge of the part. The box-shaped grid cells stand out of the part. made up to this point will be overwritten by the new fragment, if they lie within the part. 4.2 Select Fragments The selection and the showing and hiding of fragments works in the same way as with parts in the standard interface. You can select fragments by clicking on them in the screen or in the project tree. If you hold shift, you add fragments to the selection. If you hold Ctrl, you can both add and remove fragments. Selected fragments are always green (by default, this can be changed in the settings) Selection Options Further selection options are made available in the toolbar. By clicking on the first of three fragment selection icons, you select all fragments, with the second icon you deselect all fragments and with the third icon you invert the selection, which means that selected fragments are deselected and unselected fragments are selected. Also, you can select all visible or all invisible fragment (see chapter 4.3.2).

63 VIEWING OPTIONS FOR FRAGMENTS Viewing Options for Fragments General Viewing Options Whenever one or more fragments are selected you can change viewing options in the tabsheet. The part which is displayed together with the fragments can be hidden if you untick the box Show Part. This can make the view on the fragments more clear, but removes the combined display of part and structure. If you show the base area, the X-Y-bottom-plane of the grid is displayed as a red grid beneath the part (figure 4.4). Figure 4.4: The base area is displayed as a red grid at the bottom plane With the cell preview, you can see how structure cells will be inserted into selected fragments with current settings. The structure cells are represented with a red grid. That way, you can easily see how the structure cells fit into your fragments and in which section of the part a structure is inserted (fig 4.5). With bigger structure cells than grid cells, you can use the Translation to shift the structure cells by one grid cell in the direction of the three axis (see chapter 4.7) Hide and Show Fragments As parts in the standard interface, fragments can be hidden from view and shown again, if you click on the little eye-icon next to them in the project menu. These options are also available in the tabsheet (figure 4.6).

64 VIEWING OPTIONS FOR FRAGMENTS 63 Figure 4.5: The structure cells are displayed with a red grid. On the left, the structure cells and the grid cells have the same size. On the right, the structure cells are bigger than the grid cells and do not fit completely into the fragment. Figure 4.6: You can edit the visualization of a selected fragment in the tabsheet If you tick Enable Transparency in the tabsheet, a third option is available, with which fragments can be displayed transparently. This visualization option is symbolized by a Ghost-icon in the project tree and enables you to see fragments in the core of parts without completely hiding the fragments in front of it. So, you can simultaneously see fragments in the foreground and in the background (figure 4.7). In the toolbar, there are additional default options for showing and hiding fragments: With the first three icons on the left, you can show all fragments, hide all fragments or invert the shown and hidden fragments. Transparent fragments are here defined as hidden fragments and consequently will be shown after the inversion. The two eye-icons on the right simply show and hide selected fragments. The four icons in the middle interact with the selection of fragments: With the first, all shown fragments are selected. With the second, all hidden fragments are selected. With the third, all selected fragments are shown, and with the fourth, all

65 VIEWING OPTIONS FOR FRAGMENTS 64 Figure 4.7: The bottom fragment of this part is visualized transparently, allowing a view to the fragments behind selected fragments are hidden Fragment Names and Colors The names of the fragments are standardized according to the operations from which the fragments result. You can change that name in the tabsheet by entering your preferred name into the field at the top (figure 4.8). Figure 4.8: Enter the new name for the fragment in the top field To create a visual contrast between fragments, they automatically have different colors (as long as they are not selected). If you want to change the color of fragments, choose Change Color in the context menu of the fragment, click on the grid cell icon in the top-left of the tabsheet or double-click on the colored grid-cell-icon depicted next to the fragment in the project tree.

66 FRAGMENT MANAGEMENT Fragment Management Split into Connected Fragments If you right-click on a fragment and choose "Split into connected fragments", all selected fragments are split apart, so that only connected grid cells belong to the same fragment. If a fragment consists of two components, for example, and these two regions are not connected, they will both become an own fragment (figures 4.9, 4.10). Figure 4.9: Left: The selected fragment consists of two components at the top and bottom. Right: With the function "Split into connected fragments", the fragment is divided into two fragments representing the two components Select Grid Cells After you activate this feature by clicking on the icon in the toolbar, you can mark single grid cells by clicking on them in the screen. They are then coloured bright blue. If you click on more than one, they are all selected. They are removed from the selection, when you click on them again. You can select grid cells from different fragments (figure 4.11). After selecting grid cells, right-click anywhere on the screen to edit those cells. A context menu opens in where you have four options. If you "Reset" the selection,

67 FRAGMENT MANAGEMENT 66 Figure 4.10: Left: Two fragments in the form of a chessboard, one is selected. Right: With the function "Split into connected fragments", every component of connected grid cells becomes an own fragment. Figure 4.11: Cells from both fragments are selected and coloured bright blue. all cells are deselected. If you "split off selected grid cells", the selected grid cells become an own fragment. You can also split them off with a button in the Actions field of the tabsheet (figure 4.13). If you "Move selected grid cells to", you get a submenu in which all your fragments are listed. After you click on one of them, the selected grid cells are added to this fragment. If you choose "Remove selected grid cells", the cells are deleted (figure 4.12).

68 FRAGMENT MANAGEMENT 67 Figure 4.12: Top Left: Choose an option in the context menu to edit the selected cells. Top right: The selected cells are split off and have become an own fragment. Bottom left: The selected grid cells have been moved to the right fragment. Bottom right: The selected grid cells have been deleted. Figure 4.13: You can also split off the selected cells in the tabsheet Merge Fragments If you want to unify fragments, simply select all fragments you want to merge, rightclick on one of them and choose "Merge" in the context menu. The fragments will then belong together and become one fragment. As it is not necessary for fragments that its grid cells are connected, it is possible to merge fragments in any position.

69 FRAGMENT MANAGEMENT Groups In the project tree, the fragments of a part are listed in the volume data directory. To arrange fragments in the project tree, you can create subgroups, if you right-click on the volume data and choose "Create new subgroup" in the context menu. This subgroup is a subordinate directory of the volume data directory. You can move fragments into subgroups or into volume groups by drag & drop within the project tree. (Volume groups are created during the creation of the volume data in the 3S Generator, see chapter 3.1) You can also drag whole subgroups into volume groups. Fragments or subgroups cannot be moved into other volume data sets. If you move a fragment into a volume group, the structure cell you have assigned to this group is automatically inserted into the grid cells of the fragment. The subgroups can be very helpful, if you have a long list of fragments and you want groups of fragments listed together (figure 4.14). Figure 4.14: A volume data in the project tree including volume groups and subgroups You can remove groups only when they are empty. By clicking on "Remove empty groups", all groups without content are deleted. If you want to rename a group, choose "Rename Volume Group" in the context menu and type in the new name in the dialog box.

70 FRAGMENT MANAGEMENT Delete Fragments You can delete fragments, if you select them, then right-click on them and choose "Delete selected fragments" in the context menu. If you want to delete only single fragments, you can also double-click on the red-x-icon next to the fragment in the project tree. After you have removed a fragment, the grid cells previously occupied by that fragment are empty. This means that you can neither assign a structure cell to this area of the part nor produce it solidly. When you create a slice out of the structure, which subsequently will be prepared for production, the section of the deleted fragment will be empty Reset Fragmentation If you reset the fragmentation, the fragments of these volume data will be deleted. You will have to rasterize the part again to get a basic fragment and start new fragmentation operations. This option is available in the context menu of the volume data or any of its contents Enlarge Grid In the context menu of the volume data or any of its contents, you can choose to enlarge the grid. The grid is the frame which forms the boundary to which fragments can be projected or expanded. In a dialog box, the current size of the grid is specified and you can expand the grid in both directions of all three axis (figure 4.15). The current size along the three axes is constituted of the cell size multiplied with the cell count. To the right, the lowest and highest coordinates of the outbox along all three axes are specified. This specifies the position of the part in your netfabb platform. This function is only needed, if you want to have a structure bigger than the part. For example, it can make sense to enlarge the grid in minus Z to insert a support structure below the part.

71 CUT FRAGMENTS 70 Figure 4.15: Enter a number of grid cells for each direction Figure 4.16: The grid is enlarged in plus-x direction. This can be seen, as the visualized base area, along the X-axis, has become much longer as the part. 4.5 Cut Fragments To cut a fragment and thereby divide it into two, the fragment must first be selected. Then, you can choose to cut out a cubic box or to perform a free cut. Both options are available in the toolbar. All selected fragments are cut with the same specifications. Cuts are performed as soon as you click on the "Cut" button in the tabsheet or rightclick on the fragment and click on "Cut" in the context menu. You can also change the selection with that right-click. If you hold Shift or Ctrl, fragments can be added to the selection by a right-click, if you hold Ctrl, they can also be removed.

72 CUT FRAGMENTS Cut Box If you click on "Cut Box", the corners, edges and the center of a box are displayed in the screen in bright blue. The corner points and center are always visible, while the edges are only visible when they are in the foreground. All grid cells within this box or touching this box will eventually be cut out of the fragment and assigned to a new fragment. You can change the shape of the box by drag & drop, if you click on the corner points, hold the left mouse button and move the mouse (figure 4.17). The whole box can be moved, if you click on the central point and move the mouse. For the exact positioning and shaping of the box, it is often necessary to change the perspective during the process. This makes it easier to adjust the edges along the three axes. Figure 4.17: Move the corners or the whole box by drag & drop. Change the perspective for exact positioning of the box Free Cut If you click on "Free Cut", you can insert cutting lines with left-clicks. Each leftclick inserts a point and a cutting line connected to the last point you added. As soon

73 CUT FRAGMENTS 72 Figure 4.18: The resulting fragmentation: All grid cells within the box from figure 4.17 are assigned to a new fragment as you have three points, you will automatically get a triangle of cutting lines. The next point will always be connected to the first and last point you added. If you click exactly on a cutting line, a point will be added on that line. If you right-click on a point, that point will be removed. To change the shape of the cutting line, you can move the points by drag & drop. When you perform the cut, the cutting line is projected through the raster from the perspective you look at it and selected fragments are cut along that line (figure 4.19). When you change the perspective, the cutting lines are not changed. Consequently, the performed cut depends on the perspective. Figure 4.19: Insert points with mouse-clicks and move them by drag & drop. The cut is then performed along the connecting lines.

74 FRAGMENTATION TOOLS Fragmentation Tools There are several fragmentation tools by which you can split or edit selected fragments. They can be accessed via the context menu, after right-clicking either on the fragments in the screen or in the project tree. A dialog box is opened where you can directly switch between the different tools with tabsheet registers. If more than one fragment is selected, the operation is applied to all selected fragments. The fragments are treated separately and NOT as one fragment Create Skin Here, a fragment can be split into a core fragment and an outer hull or outer walls. You can specify the preferred wall thickness for six directions, being a plus and a minus direction for each axis. The plus direction is going along the respective axis towards more positive values, the minus direction towards negative values. From each of those directions, the defined number of grid cells is split off, starting with the last cell of that fragment along each line of grid cells in that direction. If you enter a hull thickness of two grid cells in plus X direction, for example, all grid cells with less than two neighboring grid cells in the plus X direction are split off and added to the hull (figure 4.20, 4.21). The operation is performed when you click on the "Create Skin" button. Figure 4.20: Enter a number of grid cells for each direction

75 FRAGMENTATION TOOLS 74 Figure 4.21: The resulting hull Split Off Blocks This function calculates the insertion of same-sized blocks of grid cells into the fragment. The size of these blocks can be defined in the dialog box. Grid cells which do not fit into those blocks are split off from the fragment. This makes sense when you want to insert a structure cell into the fragment which is bigger than the voxel size (=size of the grid cells) and does not fit into the shape of your fragment. Enter the size of the structure cell along all three axes and click on "Split off blocks". If you enter a blocksize X=3, Y=3 and Z=3, for example, all grid cells that do not fit into blocks of that size are split off and become a new fragment (figure 4.22, 4.23). If you add a translation for one of the three axes, the insertion of the blocks will start at other coordinates. If you leave zero for all three axes, the calculation starts at the coordinates X=0, Y=0, Z=0. If you tick the box "Fill incomplete blocks", the grid cells not fitting into the blocks are not split off. Instead, grid cells are added to the fragment to fill up the blocks, if no other fragments are occupy the necessary grid cells. If the box "Overwrite grid cells of other fragments" is ticked as well, other fragments or parts of other fragments within the section of the new fragment are overwritten (figure 4.23). Splitting off blocks can be very useful if you have structure cells with different sizes.

76 FRAGMENTATION TOOLS 75 Figure 4.22: Enter the preferred block size and translation along all three axes Figure 4.23: The resulting fragments without (left) and with (right) the option "Fill incomplete blocks". For example, you can split off blocks in the size of the bigger structure cells to be sure that the structure cells will fit rightly into the fragments (as in the script example 3 in chapter 6.3) Create Chessboard With this function you can split fragments with a three-dimensional chessboard pattern. You divide the fragment in little blocks containing a defined number of grid cells. In every direction, these blocks are then alternately assigned to the two resulting fragments.

77 FRAGMENTATION TOOLS 76 As in the function "Split off blocks", you can enter the preferred number of grid cells belonging to the blocks in the dialog box. This can be done for all three axes. If you enter Blocksize X: 2, Blocksize Y: 4 and Blocksize Z: 2, for example, the blocks will have a length of two grid cells along the X- and Z-axes and a length of four grid cells along the Y-axis (figure 4.24, 4.25). If you add a translation in one of the three directions, the chessboard pattern will start at other coordinates. If you leave zero for all three axes, the calculation starts at the coordinates X=0, Y=0, Z=0. The operation is performed when you click on the "Create Chessboard" button. Figure 4.24: Enter the preferred block size and translation along all three axes Figure 4.25: The resulting fragments arranged in a chessboard pattern The function "Create Chessboard" can also be used to divide a fragment into a two-

78 FRAGMENTATION TOOLS 77 dimensional chessboard (with one value very higher than the number of grid cells in that direction) or even into layers (two high values). If you enter very high numbers for X and Y and the value 1 for Z, for example, you will have horizontal layers of grid cells which will alternately belong to two different fragments Randomize This function is similar to the chessboard function, with the difference that the blocks are assigned randomly to the resulting fragments. The threshold determines the percentage of blocks which shall be cut out and assigned to the new fragment (figure 4.26, 4.27). The operation is performed when you click on the "Randomize" button. Figure 4.26: Enter the preferred block size and translation along all three axes Projection You can create projections along all three axes and in both directions of every axis. A projection is a new fragment, for which new grid cells are created and added to the part. They are inserted to fill up the space between the selected fragment and the end of the grid in the chosen direction (figure 4.28, 4.29). This function is often used to create supports for the production of the part. If you intend to do this, project towards minus Z. The operation is performed when you select a direction and click on the "Create Projection" button. If the box "Overwrite grid cells of other fragments" is ticked, other fragments or parts of other fragments within the section of the new projection

79 FRAGMENTATION TOOLS 78 Figure 4.27: Two fragments with blocks assigned randomly fragment are overwritten. If it is not ticked, those sections will remain and will not belong to the projection fragment. Figure 4.28: Choose the direction of the projection Expand If you expand a fragment, a new fragment with new grid cells is added to the grid as expansion of the selected fragment. In the dialog box, there are fields to preset the number of grid cells which shall be added in which direction. If you choose an expansion of one in plus X, for example, the expansion fragment will contain one

80 FRAGMENTATION TOOLS 79 Figure 4.29: The projection is added to the original fragment. grid cell following each final grid cell of the original fragment in the plus X direction (figure 4.30, 4.31). The operation is performed when you click on the "Expand" button. If the box "Overwrite grid cells of other fragments" is ticked, other fragments or parts of other fragments may be overwritten by the expansion. If it is not ticked, those sections will remain and will not belong to the expansion fragment. Figure 4.30: Enter a number of grid cells for each direction Split by Environment You can split off grid cells of selected fragments, which are lying on the outside of the whole part. If you enter "Environment in plus X: 2", for example, all grid cells

81 FRAGMENTATION TOOLS 80 Figure 4.31: An expansion by one cell with less than two neighboring grid cells with a higher X-value are split off and added to a new fragment (figure 4.32, 4.33), no matter which fragment these neighbouring grid cells belong to. So, similar to the "Create Hull" tool, it allows you to create hulls or walls around a fragment, only that grid cells of other fragments are taken into account too. The operation is performed when you click on the "Split" button. Figure 4.32: Enter a number of grid cells for each direction

82 ASSIGN STRUCTURE CELLS 81 Figure 4.33: Left: The original part consisting of two fragments. Right: "Split by Environment" is performed. A hull of cells at the outside of the whole part is split off from the selected fragment. Cells neighbouring the grey fragment are not defined as outside. 4.7 Assign Structure Cells When you have selected a fragment, you can assign structure cells to the fragment in the tabsheet. Click on the "Cell" dropdown menu and select either "solid" or one of your cells (figure 4.34). Figure 4.34: Choose a cell from the dropdown menu If you choose "solid", the selected fragment of the part will be sliced like a solid part. If you choose a structure cell, that cell is placed and multiplied within the fragment. The cells are arranged in a three-dimensional grid to form a connective structure in

83 ASSIGN STRUCTURE CELLS 82 the fragment. If the cell size and the voxel size of the fragment are identical, one cell is inserted into every grid cell. If the cell is smaller than the voxel size (which is not recommended! Enter a smaller grid size in your volume data in the 3S Generator!), more than one structure cell is inserted into one grid cell, and if it is bigger, the structure cells will simply occupy more than one grid cell (as in figure 4.35). In that case, only part of a structure cell may be inserted at the end of the fragment. Figure 4.35: Preview of the position and size of the chosen cell A preview of the cells in the fragment can be seen when you tick the box "Show Cell Preview" in the tabsheet. This adds a red grid to the part representing the structure cells inserted into fragments (figure 4.35). Below the dropdown menu for the structure cell, you can edit the translation along the three axes. You can either enter a value, change the value with the little arrow buttons to the right of it or alter the value with the scroll button of your mouse after left-clicking on the field displaying the value. The unit for those values is one voxel size. The translation determines the position where the first structure cell is inserted. This first cell determines the position of all other cells, as these follow each other. If you have a translation of X:2, Y:1 and Z:0, for example, a crossing of structure cells will be positioned after the second grid cell in X-direction and the first grid cell in Y-direction (figure 4.36). If the red grid stands out of the fragment, the complete structure cells will still be realized in the structure and you may get overlapping structure cells.

84 ASSIGN STRUCTURE CELLS 83 Figure 4.36: Change the translation values (top) to change the position of the structure cells You can assign a different structure cell to each fragment. Thus, different sections of your part will have different interior structures.

85 CREATE SIMULATION 84 Chapter 5 Preparation of the Structure for Production 5.1 Create Simulation You can view a simulation of your structure, if you click on the button "Create Simulation". This button is available at the top of the tabsheet, when you have selected the structure in the project tree, or at the bottom of the tabsheet, when you have selected any subordinate element of the structure. Alternatively, it is available in the context menu of the same elements in the project tree. A simulation is a three-dimensional preview of your structure, constructed with help of your cells. It displays bars, faces and STL-elements of the multiplied cells, but does not take into account any bar profiles or face specifications. Solid areas are not displayed. The part is displayed in a transparent way, enabling a view on both its exterior shape and its interior structure (figure 5.1). If you have more than one set of volume data, all of them are included in the simulation and you can have several structures in the same position, allowing you to insert several structure cells in the same sections of parts. When the simulation is displayed, you will always return to the structure screen, where the following options are available in the tabsheet: Clear Simulation memory: If you clear the simulation memory, the simulation is removed from the screen. Save simulation: You can save your simulation as 3ssimulation-file and use it, for

86 EXPORT STRUCTURE AS STL 85 Figure 5.1: A simulation of the structure of a sphere, including two different fragments with different structure cells. The sphere itself is still shown transparently. example, for stability tests in a simulator. Export simulation as STEP: By pressing this button you can save your simulation as.step file. A browser window opens where you can choose the destination directory and enter a file name. 5.2 Export Structure as STL When you have selected a structure in the 3S Executor, you can either export the structure as three-dimensional STL file or create a slice preview which can then be saved as slice file. If you click on the button "Export as STL", the structure is saved as STL-file. It is not recommended to export complex or very big structures as STL, if it is not necessary for your production process, as this can afford very long calculation time. For production processes, it is not necessary to save the structure as STL-file, as you only need a slice file. The work with two-and-a-half-dimensional data allows a substantial increase of processable data complexity, avoiding the step of STL generation.

87 SLICE STRUCTURE Slice Structure For manufacturing a structure with many 3D-printing technologies, it is necessary that you create slice data, which can later be exported as file compatible with your machine. In the tabsheet of fragments, you can set the layer size for the slice process after clicking on the "..." button. It is predefined by your specifications in the volume data of the 3S Generator, but can be altered here. It is recommended to choose a layer size which is compatible with the machine you intend to use for the production of the part (figure 5.2). Figure 5.2: Adjust the layer size for the slicing process in the tabsheet of a fragment If you then click on the structure in the project tree, the tabsheet offers the option "Slice". A slice file with your structure is created and is inserted as subordinate element named "Preview" into the structure s directory in the project tree. It is automatically displayed as 2 1/2-dimensional slice file. If you do not want to slice the whole structure, but only specific fragments, hide all other fragments, as only shown fragments are sliced. Only if the hidden fragments are solid, they are sliced anyway. So, if you do not want to slice solid fragments,

88 SLICE STRUCTURE 87 Figure 5.3: Create a slice preview assign "nothing" (or a structure cell and hide the fragments), slice the structure and then make the fragment solid again. If the option "Cut with part contour" is chosen in the volume data of the 3S Generator, a Boolean operation is automatically conducted for the slice, creating a cross section of the part and the structure. That means that all grid cells standing out of the original part are cut along the surface of the part, and only the sections of the structure which are really within the part remain in the slice (figure 5.4). To see this effect, the box "Preview Calculations" in the tabsheet has to be ticked. However, calculation time during browsing through the slices may be slowed down, if this box is ticked. Figure 5.4: The effect of the function "Cut with part contour" (right) can only be seen, if the box "Calculate" is ticked

89 THE STRUCTURE IN THE SLICE COMMANDER The Structure in the Slice Commander All options of the Slice Commander are already available in for the structure slice. If you slice the structure more than once, for example with different structure cells, they are both available in the same screen. To combine the structure slice with other slices, such as the original part, you can move the slice into the Slice Commander by drag & drop within the project tree (drag the preview into the Slices section). There, the preview is treated as any other slice and you can perform any slice operations, such as offsetting, Boolean, reducing points (important!) and hatching. The result of operations can be seen with the option "Preview Calculations" in the tabsheet. To undo an operation, choose "Clear grouping" in the context menu. A group of slices will be added to the project tree containing the original slices Example: Create Hollow Part with Interior Structure If you want to have a solid hull with the shape of the part, you can, of course, create a hull fragment and assign solid grid cells. Alternatively, you can insert the structure into the part within the Slice Commander: First, move the slice preview into the Slices section in the project tree. (The structure should be sliced with the option "Cut with part contour".) Then, slice the part itself by dragging it into the Slices section. It is important, that you have not moved the part after adding the structure to the part. If you have done so, the sliced part and the sliced structure will not be positioned at the same coordinates. Also, it is important that you choose the same layer size for the part and the structure. Next, select the three-dimensional part and use "Create Shell" to create an inner offset of the part. Create this offset as slice. The thickness you enter here will eventually be the thickness of the solid wall. Finally, conduct two Boolean operations: First, subtract the inner offset of the original part. Second, unify the resulting part with the structure (figure 5.5) Example: Point Reduction As structures often result in very complex slices, the function "Point Reduction" in the context menu is recommended to decrease processing time. Many bars of structures are very thin and their number of corners may not make any difference, as

90 THE STRUCTURE IN THE SLICE COMMANDER 89 Figure 5.5: Top left to right: The pure structure, sliced with the option "Cut with part contour". A slice of the original part is added. An inner offset of the part is created. Middle: Two Boolean Operations: First, the inner offset is subtracted from the original part, resulting in a hollow part. Second, that hollow part is unified with the structure, adding the inner structure to the solid hull of the part. Bottom: The resulting part.

91 THE STRUCTURE IN THE SLICE COMMANDER 90 the manufacturing machine may not be able to produce such fine contours. On the other hand, with many repetitions of the structure cell, a slight point reduction can save processing and production time and reduce data volume by a high proportion (figure 5.6). Figure 5.6: A crossing of structure bars in a slice layer. Top: Without point reduction each contour has 16 corner points. Bottom: With point reduction the contours have only eight corner points. Please pay attention with the maximum deformation you enter for the point reduction. If you have a very fine structure, you will have to enter a very low tolerance so that the structure keeps the right shape and not too many points are removed. You can see the result of the point reduction, if you tick the box "Preview Calculations" in the tabsheet. If the result is not satisfying, you can undo it with "Clear Grouping" in the context menu (see above) Export Slice in machine-specific format To finally create a slice file ready for your machine, right-click on the slice, move your mouse cursor to open the "Export" submenu and choose the file type you need for your machine. This opens a file browser where you can save the slice file.

92 ADD SCRIPTS 91 Chapter 6 3S Scripts The 3S scripting allows you to pre-program all functions of the Selective Space Structures. They are automatically performed with the execution of the script. For the programming, LUA script language is used. 6.1 Add Scripts Each structure in the structure library has a subdirectory "Scripts". You can add scripts to that directory by double-clicking on the blue Plus-icon to its right, or by right-clicking on the directory and choosing "Create New Script". Similarly, scripts are removed from the project by a double-click on the red X-icon or in their context menu. Figure 6.1: The scripts as subordinate directory of a structure in the project tree The scripts apply to the 3S Executor, as you can preset you fragmentation, the execution of all volume tools and assign cells to fragments. When the script is selected, orders can be inserted in the main screen, which is used as text screen. In the tabsheet,

93 ADD SCRIPTS 92 you can choose at which point your script is executed and check, if your programming syntax is correct (figure 6.2). Figure 6.2: The tabsheet of a script In the first field, you can enter a new name for the script. If the box "Execute at application of structure" is ticked, the script is automatically executed when you apply the structure to a part. If it is not ticked, there are still two ways to execute the script. If "Show in 3S Executor" is ticked, the script appears in the tabsheet when the structure is selected in the parts section of the project tree. There, it can be executed with one left-click (figure 6.3). In the Debugger section of the script s tabsheet, you can click on the button "..." and select a part with the script s structure. Then, click on "Execute" to apply the script to that structure in the 3S Executor. With the "Check Syntax" button, your script is checked for applicability. If there is any mistake or if any order cannot be executed, this will be specified.

94 THE LUA SCRIPT LANGUAGE 93 Figure 6.3: If "Show in 3S Executor" is ticked, you can execute your scripts in the tabsheet of the structure in Parts section of the project tree 6.2 The LUA Script Language The programming language is based on the LUA script language. With this objectoriented and flexible command structure, you can enter orders for operations which can be conducted each time you apply the structure to the part, or can be conducted by one mouse-click later on. As reference for the LUA language, look up the official manual ( Basic LUA Orders The following basic orders for LUA are regularly used in the Script module: Lua-Objects: Methods are activated with ":": object:method(...); Properties are accessed with ".": object.property; Variables: Values are assigned to variable by a simple "=": Variable = Value Variables are defined by such assignments. For many operations in the netfabb script module, you can choose any name as variable and assign elements of the 3S module to that name. Example: cell=structure:findcell("cell1"); Effect: The cell with the name "cell1" in the 3S Generator is from now on referred

95 THE LUA SCRIPT LANGUAGE 94 to as "cell" in the script. For some methods, you can optionally add a the Boolean value "true" or "false". Relational operators: == Equality ~= Negation of equality < less than <= less or equal > greater than >= greater or equal Arithmetic Operators: +, -, *, / Basic arithmetic operations Exponent and, or, not Boolean Operations Conditions: if condition then block end if condition then block1 else block2 end if condition then block1 elseif condition2 then block2 else block3 end for variable = start, end, jump distance do block end while condition do block end repeat block until condition Abort: break

96 6.2.2 Commands for the Script Module The following methods and properties are available for the netfabb script module. Read only properties are often used as part of conditions or calculations, but do not directly perform any function.: LUAStructure Commands for the LUAStructure class. They apply for the whole structure. Functions: Name Parameters Result Use Example Effect log string message, - Insert the message displayed structure:log("part At the respective stage of the [num- during calculations triggered finished"); execution of the script, "Part ber progress] by the script. finished" is displayed. getvolumedata number index LUA Volume Data A set of volume data of your structure is loaded into the script. The number index represents the count of the volume data in the 3S generator, starting the count with 0. volumedata= structure: getvolumedata(0); The first set of volume data of the structure is from now on referred to as "volumedata" in the script. THE LUA SCRIPT LANGUAGE 95

97 Name Parameters Result Use Example Effect findvolumedata string name LUA Volume Data As above, only without a number, but with insertion of the name of the volume data. volumedata= structure:findvolumedata ("volume1"); The set of volume data with the name "volume1" in the 3S Generator is from now on referred to as "volumedata" in the script. getcell number index LUABase Cell Loads a structure cell into the script. The number index represents the count of the cell in the structure, starting with 0. cell=structure: getcell(0) The first cell of the structure in the 3S Generator is from now on referred to as "cell" in the script. findcell string name LUABase Cell As above, only without a number, but with insertion of the name of the cell. cell=structure: findcell("cell1"); The cell with the name "cell1" in the 3S Generator is from now on referred to as "cell" in the script. executescript string name - Executes an other script as part of current script. structure:executescript("script1"); Script1 is executed during execution of current script. THE LUA SCRIPT LANGUAGE 96

98 Properties: Name Type Result Use Example Effect volumedatacount number read Reads the count of volume data sets if Condition: if there are two only in the 3S executor. volume.volume- datacount(2) sets of volume data cellcount number read Reads the count of structure cells if Condition: If there are two only cell.cellcount(2) cells simulateafter execution boolean read and write After the script is executed in the 3S Executor, a simulation of the structure structure.simulate afterexecution= Executes the function "Create Simulation" is automatically created. true; LUAVolumeData Commands for the LUAVolume class. They refer to volume data in the script and therefore apply for the volume data in your 3S Executor. Functions: Name Parameters Result Use Example Effect reset - - All operations conducted with the volume data are undone. volumedata: reset(); The function "Reset Fragmentation" of the 3S Executor is performed. THE LUA SCRIPT LANGUAGE 97

99 Name Parameters Result Use Example Effect cleanup - - Removes all empty fragments volumedata: All fragments which no cleanup(); longer contain any grid cells are deleted getfragment number index LUA Volume Data Fragment findfragment string name LUA Volume Data Fragment getgroup number index LUA Volume DataGroup Loads a fragment of your fragment=volume volume data into the script. data:get The number index represents the count of the frag- fragment(0); ment in the volume data, starting with 0. As above, only without a fragment=volume number, but with insertion data:findfragment of the name of the fragment. ("fragment1"); Loads a volume group of group=volume your volume data into the data:getgroup(0); script. The number index represents the count of the volume group in the volume data, starting with 0. The first fragment of "volumedata" in the 3S Executor is from now on referred to as "fragment" in the script. The fragment with the name "fragment1" in "volumedata" in the 3S Executor is from now on referred to as "fragment" in the script. The first volume group or subgroup in "volumedata" in the 3S Executor is from now on referred to as "group" in the script. THE LUA SCRIPT LANGUAGE 98

100 Name Parameters Result Use Example Effect findgroup string name LUA As above, only without a group=volume The volume group or Volume DataGroup number, but with insertion of the name of the volume group. data:findgroup ("group1"); subgroup with the name "group1" in "volumedata" in the 3S Executor is from now on referred to as "group" in the script. addgroup string name LUA Volume DataGroup Adds a new subgroup to the structure in the 3S Executor group=volume data:addgroup ("group1"); A new subgroup referred to as "group" in the script is added to the part. addmeshto raster - LUA Volume Data Your part is rasterized and a basic fragment is inserted. volumedata: addmeshtoraster(); The function "Grid Part" of the 3S Executor is performed. Fragment resize number plusx, - The grid is enlarged by a volumedata:resize Executes the function "Enlarge number plusy, number of grid cells you (1,1,1,2,2,2); Grid" with an expan- number plusz, specify in the parameters. sion of Plus 1 and Minus 2 number minusx, This has no effect on existing along all three axes. number minusy, fragments. number minusz THE LUA SCRIPT LANGUAGE 99

101 Name Parameters Result Use Example Effect merge object fragment1/ LUA The fragments or groups part=volume fragment1 and fragment2 group1, [object Volume specified in the parameters data:merge are merged as with the fragment2/group2], [object fragment3/ Data Fragment are merged and become one fragment. (fragment1, fragment2); function "Merge" and will be referred to as "part" in group3], [object the script. fragment4/group4], [object fragment5/ group5], [object fragment6/group6] Properties: Name Type Attribute Use Example Effect name string read only Reads the name of the volume data volumedata.name; visible boolean read and Makes the volume data visible volumedata.visible "volumedata" is not visible, write or invisible in the struc- ture tree of the 3S Executor. =false; as if box "Visible for user" in volume data tabsheet of the 3S Generator is unticked. rastersizex number read only Grid cell size in mm along X- axis volumedata. rastersizex THE LUA SCRIPT LANGUAGE 100

102 Name Type Attribute Use Example Effect rastersizey number read only Grid cell size in mm along Y- volumedata.rastersizey axis rastersizez number read only Grid cell size in mm along Z- volumedata.rastersizez axis sizex number read only Number of grid cells along X- volumedata.sizex axis sizey number read only Number of grid cells along Y- volumedata.sizey axis sizez number read only Number of grid cells along Z- volumedata.sizez axis originx number read only Origin of grid in platform volumedata.originx along X-axis originy number read only Origin of grid in platform volumedata.originy along Y-axis originz number read only Origin of grid in platform volumedata.originz along Z-axis fragment count number read only Number of fragments in the volumedata volumedata. fragmentcount groupcount number read only Number of volume groups an subgroups in the volume data volumedata.groupcount THE LUA SCRIPT LANGUAGE 101

103 LUAVolumeDataFragment Commands for the LUAVolumeDataFragment class. Referring to fragment in the script, they conduct fragmentation operations, including the volume tools of the 3S Executor. Funtions: Name Parameters Result Use Example Effect moveto group object group boolean Fragments can be moved into Volume groups fragment:movetogroup(gr1) "fragment" is moved into the Volume Group "gr1" generate [number blocksizex], LUA Cuts a new fragment in shape fragment1= Executes function "Create chessboard [number blocksizey], Volume of a three-dimensional chessboard fragment: Chessboard" with blocksize [number blocksizez], Data out of another fragment. generate X=2, Y=1, Z=3 and no [number translationx], [number translationy], [number translationz] Fragment The parameters are the same as in the respective function. chessboard (2,1,3,0,0,0); translations. The chessboard fragment is referred to as "fragment1" in the script and is cut out of "fragment". createhull [number minusx], LUA As in the equivalent function, a hull=fragment: A fragment referred to as [number minusy], Volume fragment is split into a core and createhull "hull" in the script is split [number minusz], Data an outer hull or outer walls. (1,0,0,2,0,0); off from "fragment" with the [number plusx], Frag- thickness Minus X=1, Plus [number plusy], ment X=2 [number plusz] THE LUA SCRIPT LANGUAGE 102

104 Name Parameters Result Use Example Effect divideblocks [number blocksizex], LUA Calculates the insertion of blocks=frag- Executes the function "Split [number blocksizey], Volume same-sized blocks into a fragment. ment:divide- off blocks" with the block- [number blocksizez], Data The size of these blocks size X=4, Y=4, Z=4 and [number translationx], Fragmenrameters. blocks is defined by the pa- (4,4,4,0,0,0); no translations. The new [number translationy], Grid cells not fitting framgent including the [number translationz], into blocks of this size are split blocks will be referred to [boolean fillblocks] off. The option "Fill incomplete as "blocks" in the script. blocks" can be activated by adding "true" as last parameter. The option "Fill incomplete blocks" is not activated. create [number type], LUA projection [boolean celloverride] Volume Data Fragment Adds a new fragment with new fragment1=frag- Executes the function "Pro- grid cells. They fill up the ment:create- space between existing grid cells and the end of the grid. The direction can be specified with the parameters. The option "Overwrite grid cells of other fragments" can be activated projection(1); projection(number) 1 = +x, 2 = -x, 3 = +y, 4 = -y, 5 = +z, 6 = -z by adding "true" as last parameter. jection" of "fragment" in the PlusX-direction. The projection fragment will be referred to as "fragment1" in the script. The option "Overwrite grid cells of other fragments" is deactivated. THE LUA SCRIPT LANGUAGE 103

105 Name Parameters Result Use Example Effect create [number minusx], LUA Adds a fragment with additional fragment1=frag- Executes the function "Ex- expansion [number minusy], Volume grid cells forming outer ment:create- pansion" with "fragment", [number minusz], Data walls of the original fragment. expansion with one grid cell added in [number plusx], Fragment The parameters determine the (0,0,0,1,2,0); Plus X direction and two [number plusy], number of added grid cells in grid cells in Minus Y direc- [number plusz], each direction. The option tion. The new fragment is [boolean celloverride] "Overwrite grid cells of other fragments" can be activated by adding "true" as last parameter. referred to as "fragment1" in the script. The option "Overwrite grid cells of other fragments" is deactivated. randomize [number blocksizex], LUA Calculates blocks with a blocksize randomfrag= Executes the function "Ran- [number blocksizey], Volume determined in the parame- fragment: domize" with a blocksize [number blocksizez], Data ters. Randomly assigns a defined randomize X=1, Y=1, Z=1, no translations [number translationx], [number translationy], [number translationz], [number probability] Fragment percentage of blocks to the new fragment. (1,1,2,0,0,0,30) and a threshold of 30%. The new fragment is referred to as "randomfrag" in the script. THE LUA SCRIPT LANGUAGE 104

106 Name Parameters Result Use Example Effect splitby environment splitinto shells [number minusx], LUA Splits off grid cells from a environfrag= Executes the function "Split [number minusy], Volume fragment, depending on the fragment:splitbyenvironment "fragment". The by Environment", based on [number minusz], Data number of neighboring grid specifica- [number plusx], Fragmention cells. That numbers and direc- (2,0,2,2,0,2) tions are Minus X=2, Minus [number plusy], are specified in the param- Y=0, Minus Z=2, Plus X=2, [number plusz] eters. It does not matter if the Plus Y=0, Plus Z=0. The neighboring grid cells belong central fragment will be referred to the same fragment. to as "environfrag" in the script. - LUA Fragment is split apart, so that fraggroup= Executes the function "Split Volume only connected grid cells belong fragment:split- into connected fragments". Data to the same fragment. If intoshells Fragmenhesive a fragment consists of two co- components, they will both become an own fragment. remove - - Deletes a fragment fragment: "fragment" is removed from remove(); the grid. THE LUA SCRIPT LANGUAGE 105

107 Properties: Name Type Attribute Use Example Effect name string read and Reads name or changes the fragment.name= "fragment" is named "Base write name of objects in the 3S Executor. "Base fragment"; fragment" in the 3S Executor. In the script, it will still be referred to as before. color number read and Changes the color of fragments fragment.color= "fragment" gets color write 49906; rastercount number read only fragment. rastercount; cell object read and Reads cell of fragment or assigns fragment.cell= "cell1" is assigned to "frag- write a cell to a fragment. cell1; ment". LUAVolumeDataGroup Commands for the LUAVolumeDataGroup class refer to groups of volume data sets in the script and modify Volume groups in the 3S Executor. THE LUA SCRIPT LANGUAGE 106

108 Functions: Name Parameters Result Use Example Effect movetogroup object group boolean Subgroups can be moved into Volume groups or other subgroups group1:movetogroup(group2); "group1" is moved into the Volume Group "group2" getfragment number LUAVolume Loads a fragment of a group fragment=group1: The first fragment of index DataFragmenber into the script. The num- getfragment(0); "group1" in the 3S Executor index represents the count of the fragment in the group, starting with 0. is from now on referred to as "fragment" in the script. findfragment string name LUAVolume As above, only without a fragment=group1: The fragment with the name DataFragment number, but with insertion of the name of the fragment. findfragment ("fragment1"); "fragment1" in "group1" in the 3S Executor is from now on referred to as "fragment" in the script. getgroup number LUAVolume Loads a subgroup of your newgroup=group1: The first subgroup of index DataGroup group into the script. The getgroup(0); "group1" in the 3S Executor number index represents the count of subgroups in the is from now on referred to as "newgroup" in the script. group, starting with 0. THE LUA SCRIPT LANGUAGE 107

109 Name Parameters Result Use Example Effect findgroup string name LUAVolume As above, only without a newgroup=group1: The subgroup with the name DataGroup number, but with insertion of the name of the group. findgroup ("group2"); "group2" in "group1" in the 3S Executor is from now on referred to as "newgroup" in the script. addgroup string name LUAVolume DataGroup Adds a new subgroup to the group in the 3S Executor group=group1: addgroup ("group1"); A new subgroup referred to as "group" in the script is added to "group1". Properties: Name Parameters Result Use Example Effect name string read and Reads name or changes the name group1.name= "group1" is named "Core write of objects in the 3S Executor. In "Core fragments"tor. fragments" in the 3S Execu- the script, it will still be referred to as before. fragmentcount number read only Number of fragments in group group1.fragmentcount subgroupcount number read only Number of subgroups in group group1.subgroupcount THE LUA SCRIPT LANGUAGE 108

110 LUABaseCell Commands for the LUABaseCell class. They give information on the structure cells generated on the 3S Generator and loaded into the script. Properties: Name Parameters Result Use Example Effect name string read only Name of the cell "cell"=cell.name; sizex number read only Size of the cell along X-axis cell.sizex sizey number read only Size of the cell along Y-axis cell.sizey sizez number read only Size of the cell along Z-axis cell.sizez THE LUA SCRIPT LANGUAGE 109

111 SCRIPT EXAMPLES Script Examples The work with scripts can be demonstrated with some basic examples: Example 1 Figure 6.4: Script example 1 The first script example (figure 6.4) automatically executes the following working steps in the 3S module. Getting volume data: The information of the volume data in the 3S Generator is loaded into the script, referred to as "volume" data. Getting Cell: The cell with the name "diamond" is loaded into the script and will be referred to as "cell". Initialising: The part is cleared of all fragments.

112 SCRIPT EXAMPLES 111 Rastering the part: The part is gridded and a new fragment is created, overwriting all other fragments within the part. The new fragment is referred to as "fragment" in the script. Create Shell: A hull of the fragment is created with the parameter "3" for all axes and all directions. The hull fragment will be referred to as "hull" (figure 6.5). Figure 6.5: Example 1: The resulting fragments in the project tree. Assign cell: The structure cell "cell" is assigned to the core fragment "fragment". Final Cleanup: All empty fragments containing no more grid cells are removed. Create Simulation: After execution of the script, a simulation of the part will be created (figure 6.6). Figure 6.6: Example 1: A simulation is created automatically. In the core fragment, there is a structure. The outer fragment does not contain a structure.

113 SCRIPT EXAMPLES 112 Example 2 Example 2 is similar to Example 1, but contains one more cell and an additional fragmentation operation (figure 6.7). Figure 6.7: Script example 2 Divide blocks off: Blocks with blocksize X=2, Y=2, Z=2 are split off from the core fragment ("fragment"). This block fragment is referred to as "blocks" (figure 6.8). Assign cells: The structure cell "cell1" is assigned to the remains of the core fragment, "cell2" is assigned to the fragment "blocks". The final cleanup and the creation of the simulation are equivalent to Example 1. Example 3 This example is a more complex script (figure 6.10). In the structure, there are six different cells with different sizes (figure 6.9). With the script, these are assigned to core and hull fragments, with the biggest cells inserted into the core of the part and the finer cells inserted into the outer fragments.

114 SCRIPT EXAMPLES 113 Figure 6.8: Example 2: The fragments resulting from the script are listed in the project tree (left) and visualized in the 3S Executor (right). Figure 6.9: Example 3: The structure in the 3S Generator, containing six different cells First, the volume data is loaded and reset and the cells are loaded as "cell_1", "cell_2", "cell_4", "cell_8" and "cell_16". These names indicate the size of the cells to keep a better overview. From now on, structure logs are inserted that are displayed when the script is run, depending on how far the script has progressed (figure 6.11). After the part is gridded by "addmeshtoraster" (Name of basic fragment: "struc1_core"), a hull of this basic fragment is created with the hull thickness "1"

115 SCRIPT EXAMPLES 114 Figure 6.10: Script example 3

116 SCRIPT EXAMPLES 115 Figure 6.11: Example 3: With the order "structurelog", "Initialise Part" is displayed during the execution of the first part of the script. in each direction, and new names are assigned to the fragments in the 3S Executor (e.g. "Structure 1 - Hull"). Next, "cell1" is assigned to the fragments (figure 6.12). Figure 6.12: Example 3: Cell 1 from the script (which is "cell 1mm") is assigned to the first fragments. In the next step, the following process is repeated: From the core fragment of the previous repetition of the process, blocks with twice the size of the last repetition are split off by "divideblocks". Then, a hull of these blocks is created with the same thickness as the block size. This results in ten different fragments. The fragments are renamed and the cell fitting the block size is inserted into both fragments (figure 6.13). That way, the raster will be divided into fragments with blocks getting bigger and bigger, and the equally sized cells will fit exactly into the fragments. The creation of the hull guarantees that the respective cell remains not only in the grid cells remaining after the next split-off, but also in a hull, which will remain as well. At the end, a simulation of the structure is created.

117 SCRIPT EXAMPLES 116 Figure 6.13: Example 3. Left: The fragments resulting from the script. Right: Cells are assigned to fragments generated with the equivalent block size. Figure 6.14: Example 3: A cross section of the part. The inner fragments consist of bigger blocks of grid cells than the outer fragments. Example 4 Example 4 demonstrates, how the automatic repetition of the "Randomize" function can result in a part with a large number of randomly arranged fragments (figure 6.15).

118 SCRIPT EXAMPLES 117 Figure 6.15: Script example 4

119 SCRIPT EXAMPLES 118 The structure consists of 16 different, but same-sized cells (figure 6.16). Figure 6.16: Example 4: The structure in the 3S Generator, with 16 different cells. In the script, the volume data is loaded and reset. After the part is gridded and the name "bauteil" is assigned to the basic fragment, 15 further fragments are created with the order "randomize". The reference fragment of the randomization is altered so that, in the end, all 16 random fragments have approximately the same number of grid cells (figure 6.17). Next, a different structure cell is assigned to each fragment. As the arrangement of the fragments is coincidental, the cells are inserted randomly into the part (figure 6.18). Finally, the fragments are given numbered names in the 3S Executor, as the automatic name creation of netfabb could become very confusing in cases of repeated processes(figure 6.17).

120 SCRIPT EXAMPLES 119 Figure 6.17: Example 4: The script results in a totally randomized fragmentation. The fragments are renamed according to the cells assigned to them. Figure 6.18: Example 4: The 16 different cells are assigned to the 16 different fragments. Example 5 This example demonstrates how conditions, operators and read-only values can be used in a script (figure 6.19). The script adds a support for the construction of a part consisting of one fragment. The support is implemented as projection in minus-z direction and reaches from the bottom of the part to the bottom of the platform. After the volume data, the fragment and two cells are loaded into the script and the first cell is assigned to the fragment, there is a conditional block of LUA orders. The

121 SCRIPT EXAMPLES 120 Figure 6.19: Script example 5 conditional line ("if") determines that the following block of orders is only executed, if the origin of the grid has a higher Z-value than "0", which means that the part is not placed at the bottom of the platform. For the enlargement of the grid ("volumedata:resize"), the parameter "0" is given for all directions except the minus-z direction. For this last parameter, the lowest Z-value of the grid, which is measured in mm, is divided by the grid cell size. This results in the number of grid cells between the base of the part and the bottom of the platform and has to be done, because the enlargement is measured by the number of grid cells. Thus the grid is enlarged far enough that a projection fragment can be inserted ("fragment:createprojection"), reaching to the bottom of the platform (figure 6.20). This projection is then given the name "Support" in the 3S Executor (figure 6.21) and is filled with the cell "supportcell". The second conditional block of orders needs to be inserted for the case that the enlargement of the grid does not reach to the bottom of the platform. This can be the case when the result of the division of the origin by the cell size of the grid has been rounded down in the first block of orders. For this case, a further enlargement of the grid by one grid cell in minus-z direction is conducted and a new projection

122 SCRIPT EXAMPLES 121 Figure 6.20: Example 5: The support (blue) is inserted below the part. Figure 6.21: Example 5: The two fragments in the project tree fragment is inserted. The parameter "true" is added to overwrite the first projection fragment. As before, the new projection fragment is given the name "Support" in the 3S Executor and is filled with the cell "supportcell". Example 6 Example 6 demonstrates how operations are conducted for certain fragments only, by use of the "for" condition and of a count-variable (figure 6.22). As in Example 4, the basic fragment of the part is split into 16 random fragments. After that, the first two cells of the structure are loaded into the script, referred to as "cell_a" and "cell_b". Then, the first conditional block of orders applies to every second fragment (Jump distance: "2") of the volume data, starting with the first ("a=0") and running through