Building and Simulating a Task Lighting Model in LightTools

Building and Simulating a Task Lighting Model in LightTools Synopsys 2012 1 Introduction to LightTools, Task Lighting Walkthrough Example This is an example of modeling a task lighting system in LightTools. You will follow along with the instructor. The example will make you familiar with most basic LightTools features and the user interface (UI). Goals: Get familiar with basic controls and settings Import CAD geometry Set surface properties and finishes Add light sources Add receivers Simulate the system performance Generate a photorealistic rendering of the lit system Synopsys 2012 2 Introduction to LightTools, Task Lighting Task Lighting Page 1

Walkthrough 1 2 3 Import Geometry Set Surface Properties Add Sources 6 5 4 Add Receivers and Run Simulation Photoreal Rendering (lit) Photoreal Rendering (unlit) Synopsys 2012 3 Introduction to LightTools, Task Lighting Importing Geometry Go to File > Import > STEP Using the file dialog box, locate the Task Lighting.step in the Introduction to LightTools\ WorkshopFiles folder Accept default options in the data exchange dialog, click OK Press Fit icon on toolbar The base model is supplied as a STEP file. You need to use the STEP data exchange option to import the model into LightTools. Data Import commands are located under the File menu Synopsys 2012 4 Introduction to LightTools, Task Lighting Task Lighting Page 2

Repair Geometry Select all the imported parts (Edit > Select All) and use Repair to heal the geometryet Default repair operation attempts to do the following Substitute analytic surfaces for splines Fill gaps Combine adjacent surfaces into a continuous surface Repair Synopsys 2012 5 Introduction to LightTools, Task Lighting User Interface: Tabbed Views Views appear full size on separate tabs; left-click on tab and drag to reorder tabs Dialog boxes appear in separate windows, and can move outside of the main LightTools window Autohide window control OFF: full window remains always in front ON: window rolls up to title bar only unless cursor is on top Synopsys 2012 6 Introduction to LightTools, Task Lighting Task Lighting Page 3

User Interface: Floating Views Select Tools > Options, Layout tab (or Window > Floating Views) for resizable view windows Synopsys 2012 7 Introduction to LightTools, Task Lighting Viewing and Setting Units Zoom (Mouse Wheel) and Rotate (Right Mouse Button + <Ctrl>) the model with the mouse. You can also use Zoom buttons and Alignment buttons on the toolbar Zoom Align The STEP model was created with units of Millimeters. Go to Edit > Preferences, General Preferences > System and confirm that the current LightTools are set to Millimeters. Preferences allow you to change the default system settings such as units, optical properties, and view parameters. After changing the preferences you can retain them for future models by saving them. Right click to choose the Save option. Synopsys 2012 8 Introduction to LightTools, Task Lighting Task Lighting Page 4

Rename Objects Identify each object by selecting it in the 3D View. Rename as shown in the picture. The default names during data exchange are arbitrary. Box_L MWFrame Box_R Microwave The name of an object is unique in LightTools, and it is used to identify the object graphically and programmatically (macro). Select names so that you can easily identify each object in the model. Right-Click in the System Navigator to rename an object BackWall Base Synopsys 2012 9 Introduction to LightTools, Task Lighting Surface Properties Assign basic optical properties for the geometry. The picture shows the property assigned for each surface important for the simulation Settings shown on next slide Absorber (Optical) Surface Properties for objects can be set using the Optical Property Manager An optical property can be shared by many zones Optical properties are defined for zones, which are part of a given surface. The BareSurface is the default zone for any surface. Additional zones can be added using property zones Use the right-click menu to assign optical properties for a given property Mirror Lambertian Scatter (Diffuse) Synopsys 2012 10 Introduction to LightTools, Task Lighting Task Lighting Page 5

Optical Property Manager - 1 Use Edit>Optical Properties to access optical property manager Synopsys 2012 11 Introduction to LightTools, Task Lighting Optical Property Manager - 2 Use Optical Properties tab to define the property you want The number in parenthesis (n) indicates the number of surfaces using this optical property Synopsys 2012 12 Introduction to LightTools, Task Lighting Task Lighting Page 6

Optical Property Manager - 3 Usage tab shows all zones using a given property Use sub selection to reassign Example: Change all Cylinder surfaces to a different property Mirror Synopsys 2012 13 Introduction to LightTools, Task Lighting Optical Property Manager - 4 Color tab allows you to define custom colors for the optical property Use View>Surface Color>By Optical Property to switch from default rendering mode (By Refract Mode) Synopsys 2012 14 Introduction to LightTools, Task Lighting Task Lighting Page 7

Create Optical Properties Create 3 new optical properties and assign their properties Synopsys 2012 15 Introduction to LightTools, Task Lighting Details for Each Property Absorber Mirror (5%) Diffuser (40%) Synopsys 2012 16 Introduction to LightTools, Task Lighting Task Lighting Page 8

Assign Properties to Objects For multiple surfaces/zones, use right-click menu Repeat property assignment for other surfaces/zones You can also assign optical properties through the properties dialog box Synopsys 2012 17 Introduction to LightTools, Task Lighting Model Rendering View>Surface Color>By Optical Property (use your own colors) View>Surface Color>By Refract Mode (Fixed) Synopsys 2012 18 Introduction to LightTools, Task Lighting Task Lighting Page 9

Hide the Geometry Before adding the LED we will hide temporarily hide the geometry In the Navigation Tree select all the geometry Right-click and select Hide > All The Hide function allows you to keep the selected geometry from being displayed in the 3D Design View The hidden geometry still participates in all ray tracing The icon in the Navigation Tree is shown in grey for any hidden geometry On the Edit menu you can find controls to Show All and Swap Hidden/ Visible The Hide control is in addition to any Layer visibility settings Synopsys 2012 19 Introduction to LightTools, Task Lighting Light Sources We will use 3 LEDs to illuminate the model Manufacturer: OSRAM Model LUW-W5AM (Golden DRAGON plus) Color: White Lumens: 100.5 CRI: 80 This LED model is available in the LightTools LED Library (Tools > LED Library) LEDs will be placed here LED Library provides hundreds of LED models from various vendors It allows you to use the LED model in various modes Geometry Only Geometry + Apodization Geometry + Ray Data Note: the default ray data file has only 5000 rays. If you need the full ray set then you need to download the ray file from the vendor. For this exercise we will use the geometry + apodization mode Synopsys 2012 20 Introduction to LightTools, Task Lighting Task Lighting Page 10

Select LED We will load the LED model from the library and make 2 copies to create additional sources When you click Create LED the library will add the LED model to the 3D Design The default location of the LED will be X=Y=Z=0 (i.e., global origin) The geometry is non-traceable Units = mm LED is created as a group of multiple objects Synopsys 2012 21 Introduction to LightTools, Task Lighting Examine LED Wait for the LED Library to finish adding the LED Close the LED Library Use the Fit button on the Tool Bar to zoom in on the LED Synopsys 2012 22 Introduction to LightTools, Task Lighting Task Lighting Page 11

Copy the LED Zoom the 3D Design View out slightly using the mouse wheel In the Navigation Tree select the newly added LED On the Button Palette select Modifying > Editing > Copy Click in the 3D Design View to place the copy of the LED near the original Repeat the copy procedure to create a total of three LEDs Synopsys 2012 23 Introduction to LightTools, Task Lighting Multi-select the LEDs In the Navigation Tree <Ctrl>-click to select all three LEDs In the Tool Bar click the Info button to open the Properties box with all three LEDs selected in the tree Adding more than one entity to the Properties Dialog Box tree can be very helpful when editing multiple l objects Entities can be added to an existing Properties box by <Ctrl>-clicking on the entity in the Navigation Tree Synopsys 2012 24 Introduction to LightTools, Task Lighting Task Lighting Page 12

Set the LED Coordinates In the Properties Dialog Box Tree <Ctrl>-click to select all three LED groups On the Coordinates tab enter: X = -304.8 Y = 87.15 Alpha = -90 The values for all the selected entries are set at the same time Only works for identical property tabs Right-clicking on a field will bring up a list of current values that can be selected Synopsys 2012 25 Introduction to LightTools, Task Lighting Set the Z Offset In the Property Dialog Box Navigation Tree select each LED group in turn and set the values to: Z = -190 Z = 0 Z = 190 Click OK to save the changes and close the Property Dialog Box Synopsys 2012 26 Introduction to LightTools, Task Lighting Task Lighting Page 13

Check the LED Position Select the Edit > Show All menu item Select the View > Render Mode > Wireframe menu item On the Tool Bar select the UCSYZView button to orient the 3D Design View Verify that the LEDs have been placed properly Save the model as Task Lighting with LEDs.lts Synopsys 2012 27 Introduction to LightTools, Task Lighting Add a Receiver In order to run a simulation we need at least one source and a receiver Select View > Render Mode > Translucent Select the center surface on the base, right-click for the pop up menu, and select Add Receiver Open the receiver property box and set the units to Photometric Surface receivers are always attached to a surface or a dummy plane Surface receivers can calculate the following: Illuminance Intensity Luminance (optional) Color (optional) Each type of calculated data is shown on a Mesh (a 2D grid) Units can be Photometric (default) or Radiometric Synopsys 2012 28 Introduction to LightTools, Task Lighting Task Lighting Page 14

Run Simulation Use Ray Trace > Simulation Input to set the number of rays to 100,000 Click Begin Forward Simulation The simulation can run in the forward and backward directions. The forward simulation is more common Synopsys 2012 29 Introduction to LightTools, Task Lighting Illuminance Output Results tab for the Illuminance Mesh shows a summary of the illuminance output Mesh Data tab provides the row data for each bin on the mesh The X and Y axes on the raster chart are aligned with the X and Y coordinates of the surface Analysis > Illuminance Display > Raster Chart Synopsys 2012 30 Introduction to LightTools, Task Lighting Task Lighting Page 15

Photoreal View You can generate a photorealistic view of the model to show its appearance (a picture of the model) This can be a lit (LEDs turned on) or unlit view of the model We need to define the appearance of each surface Photoreal settings are only applicable to the photoreal view The data you see for the regular forward/backward simulation is not affected by these settings All surface settings are defined on the Finish tab Synopsys 2012 31 Introduction to LightTools, Task Lighting Creating a Photoreal View In 3D View, select Photoreal > New Photoreal View This will open a new photoreal view with the default camera angle Use CTRL+Right Mouse to rotate, align, and zoom the view (same as the 3D View) Repaint View Stop Rendering Lit Render ON/OFF Run Lit Simulation Synopsys 2012 32 Introduction to LightTools, Task Lighting Task Lighting Page 16

Selecting a Finish Select Box_L, Box_R, and MWFrame using CTRL+Left-Click in the System Navigator (use SHIFT+ Left-Click if you re selecting in the 3D View) Right-Click and select Edit All Descendents > Surfaces On the Finish tab, select Library Finishes > Nature > Wood > Varnished > Varnished mahogany and double-click to add it to the model finishes, and press "Apply" to use it for the selected surfaces Model Finishes are the currently active finishes When you apply a Library Finish, it will move to the Model Finishes Synopsys 2012 33 Introduction to LightTools, Task Lighting Repeat Finish Selection Select the BackWall and Base, right-click and select Edit All Descendents > Surfaces On Finish tab, choose Library Finishes and navigate to Nature > Rocks and Minerals > Granite > Hornblende granite Double-click on Hornblende granite to add finish to the model, and press "Apply" to use it for the selected surfaces Synopsys 2012 34 Introduction to LightTools, Task Lighting Task Lighting Page 17

Apply Finish to Individual Surfaces Front Surface (Microwave ) Top Surface (Base ) In 3D View, select an individual surface for a specific finish FrontSurface of Microwave Crystal and Glass > Refractive > Gray Glass TopSurface of Base Ceramics > Porcelain > Porcelain Color > Black You only need to set the finishes of the surfaces that are visible in the desired view Synopsys 2012 35 Introduction to LightTools, Task Lighting Photoreal View Settings Set the background to none (black) View > View Preferences Repaint the Photoreal View Select View > Contrast > Equalizing 1 2 3 Synopsys 2012 36 Introduction to LightTools, Task Lighting Task Lighting Page 18

Unlit Photoreal View Photoreal View is sensitive to the display settings on your computer In order to create the best rendering you must adjust the View > Contrast > Tone/Contrast settings as appropriate Tone/Contrast Settings Synopsys 2012 37 Introduction to LightTools, Task Lighting Lit Photoreal Simulation Using PhotoReal > Lit Simulation Input set the Total Rays to Trace = 1,000,000 Click Begin Lit Simulation Lit Simulation collects data for photoreal rendering on each surface. It will also update the regular simulation data (such as charts). The regular simulation does not collect photoreal data Typically you need a large number of rays in order to generate photoreal views with high fidelity Synopsys 2012 38 Introduction to LightTools, Task Lighting Task Lighting Page 19

Lit Photoreal View In the Photoreal View click LitOn to turn the model sources on By default the photoreal view is generated with some ambient light level in order to be able to see objects You need to balance the ambient and model lighting g when you enable lit rendering There are Studio Lights you can add to your model for different lighting effects Point Light Spot Light Distant Light Synopsys 2012 39 Introduction to LightTools, Task Lighting Getting Help There are multiple ways to access Help Help > Contents and Index (HTML) Help > Document Library (PDF) Search across all documents in the library with» or What s This? For command and Toolbar buttons, using HTML help Dialog level help (HTML) Synopsys 2012 40 Introduction to LightTools, Task Lighting Task Lighting Page 20

Workshop 1: Flashlight A simple flashlight model will be used as a sample system for photorealistic rendering. Facetted reflector; 0.85 Gaussian scatterer Bulb with cylinder source 3λ representation of a 3500K blackbody source Window Target: reflective Lambertian scatterer Synopsys 2012 41 Introduction to LightTools, Task Lighting Workshop 1: Create Photoreal View Open supplied file FlashlightPRR.1.lts Open a Photoreal View (Photoreal > New Photoreal View) Add scenery by opening the View Preferences for the Photoreal window. On the Scenery tab, select either a Base or a Room and apply to model. Example: Tiled Room Unlit appearance Synopsys 2012 42 Introduction to LightTools, Task Lighting Task Lighting Page 21

Workshop 1: Lit Rendering Run a photoreal simulation of 100,000 rays Photoreal > Lit Simulation Input to set the rays Photoreal > Begin Lit Simulation View the lit target in the Photoreal window Running the lit rendering disables the camera light; only the light from the LightTools source is visible Source spectrum is 3500K Tungsten Use Saturation to adjust color of output (View > Contrast > Tone/Contrast) Saturation=1.0 Synopsys 2012 43 Introduction to LightTools, Task Lighting Saturation=0.0 Workshop 1: Add Studio Light Add a point light above the flashlight and update the photoreal view Photoreal > Place Point Light, on command line enter XYZ 0,600,600 Note: you don t need to repeat the simulation to update the lit appearance Synopsys 2012 44 Introduction to LightTools, Task Lighting Task Lighting Page 22

Workshop 1: Change Surface Finish Currently, the surface finish on the flashlight body is the Default Mechanical Absorber. Select a different surface finish from the library and apply it to the surfaces of the flashlight body. Synopsys 2012 45 Introduction to LightTools, Task Lighting Workshop 1: Change Surface Finish (2) Example: Select FlashlightBody, right click in 3D View and Edit All Selected > Surfaces Click on Finish i tab, select Library Finishes, i Metals > Aluminum > Aluminum and double click to add to Model Finishes tab On Model Finishes tab, change color as desired Repaint the photoreal view to see the new finish In this case, you don t need to repeat the simulation since only the studio lights interact with the body of the flashlight Synopsys 2012 46 Introduction to LightTools, Task Lighting Task Lighting Page 23