Using Object Snap to Draw a Rug Design The objective of the rest of this tutorial is to learn the use of object snap and hatch. Because AutoCAD is based on vectors and coordinate geometry, it can easily find coordinate pairs. You tell AutoCAD the location with use of object snap. Used below are the different types of object snap and description of what AutoCAD will do: endp End of a line mid Midpoint of line int Intersection of two lines app Apparent Intersection (used most in 3D) cen Center point of circle or polygon quad Quadrant of circle (4 equidistant points on elide circumference) per Next point will be drawn perpendicular to object tan Tangent to object node Point location (introduced) in later exercise) ins Insertion point of a block (Introduced In later exercise) nea Nearest point 1. On the menu bar, click on File, New 2. Enter file name with your initials and rug such as jmkrug In the drawing file box. You will use most of these in making your rug design (Fig. 4-16) and the tutor will take you through it step by step. Fig 4-17 Rug design ACAD object snap tutorial Page 1
You will set up the drawing for 1 =l scale and letter-size or A-size paper. UNITS Architectural. LIMITS upper right corner at 8',11' GRID 1 ZOOM all Turn ORTHO on and use the LINE command to draw a rectangle that is 6' in the x direction and 9' in the y direction. OSNAP Command The OSNAP command establishes a running object snap mode, letting you repeatedly snap to what you select (i.e. endpoint, intersection, center etc). You can also choose multiple object snap settings. OSNAP Is found under the menu bar Tools'. But you also can use the Object Snap toolbar. To bring up the object snap toolbar Go to View menu > Toolbars Scroll down and click on the box next Object Snap until a x appears. The toolbar will appear. Move it to a convenient location on the screen. Next, set the OSNAP settings. There are three ways to access the OSNAP settings dialog box. 1. At the command line type: OSNAP 2. Right click on the OSNAP button on the status bar. Pick Settings from the pop-up menu. 3. Go to Tool menu>drafting settings command. Click on the Object Snap tab and you are in the object snap settings dialog box. In the dialogue box, click on the box next to Midpoint and "Intersection". Click on "OK" to exit the Dialogue window NOTE: Until you change this setting, you will only be allowed to draw from the midpoint of a line or the Intersections of two lines. AutoCAD will show a midpoint cursor icon (triangle) or Intersection (cross) to show that you are snapping to either of these objects. Next, you will use this object snap mode to draw a line to the midpoint of each line in the existing rectangle. The resulting drawing will be a rectangle with a in a diamond shape inside it.: 1. Give the polyline command. (At the command line type: PLINE or pl) Fig 4-17 Clicking to the midpoints of the lines PROMPT: From point (click A) Current line-width is 0-0 Arc/Close/Halfwidth/Length/Undo/Width<Endpoint of line>: (click A) ACAD object snap tutorial Page 2
Arc/Close/Halfwidth/Length/Undo/Width<Endpoint of line>: (click B) Arc/Close/Halfwidth/Length/Undo/Width<Endpoint of line>: (click C Arc/Close/Halfwidth/Length/Undo/Width<Endpoint of line>: (click D) Arc/Close/Halfwidth/Length/Undo/Width<Endpoint of line>: C OFFSET Command This command will offset a copy of an entity through either a specified point or distance. Click on the offset icon on the modify menu or type: At the command line type: OFFSET Offset distance or Through <Through>: 2 Select object to offset (click anywhere on polyline) Side to offset? (Click on Inside of polyline) Select object to offset (press ENTER or right click)) The result should be similar to the illustration (fig. 4-18). Fig. 4-18 Use of the OFFSET command to offset the polyline. NOTE: Had you just used the LINE command to make the first diamond, the lines would have overlapped. Next you will draw a circle that is tangent to the diamond. But first you will draw a construction line by finding the intersection of the diamond and outline rectangle : At the command line type: L LINE: From point (click A) To point (click B) Next, you will clear the object snap setting: Command: OSNAP 1. Click on Clear all. 2. Click on OK to exit the object snap dialogue window. ACAD object snap tutorial Page 3
Now you will type in the individual object snap icons using the midpoint and a tangent to draw the circle (Fig 4-20) Give the Circle command CIRCLE 3P/2P/TT R/<CENTER POINT> point: mid Of (click A) Diameter to Radius>: tan Of (click B) Use the Erase command to erase the construction line. In the next sequence, you will draw a polygon inside the circle. You want it to have the same center point so you will use the cen object snap. You can place the edge of the polygon on the circle by using the neat object snap option or nearest point Finally you will draw a circle: At the command line type: POLYGON Number of sides <4>: 6 Edge/<Center of polygon>: cen of (click anywhere on Circle circumference) Inscribed in circle/circumscribed about circle <I/C> <i>: (press ENTER) Radius of circle: nea to (click on the bottom of the circle circumference) ACAD object snap tutorial Page 4
Use the OFFSET command to offset the polygon 2 Inches inside. Give the Circle command CIRCLE 3P/2P/TTR/<Center Point> point>: cen of (click on circle - not the polygon) Diameter/<Radius>: tan of (click to polygon) Your drawing should look like the illustration You will set object snap to quad or quadrant to make a box inside the circle (Fig. 4-22). Bring up the OSNAP dialog box In the dialogue box, click on the box next to Quadrant to turn it on. Click on "OK" to exit the dialogue window. Give the Line Command LINE From point (click approximately at A) To point (click approximately at B) To point (click approximately at C) To point (click approximately at D) To polnt C ACAD object snap tutorial Page 5
Bring up the OSNAP settings dialog box and click on Clear all and OK to close the dialogue box Next you will use hatch patterns to make your rug design more Interesting and learn about the basic aspects of hatching. HATCH, BHATCH Commands The HATCH command draws patterns within an area or boundaries. The HATCH command requires enclosed boundary. It is easiest to use the pulldown menus to set a hatch style. Use the hatch Icon on the draw toolbar or type at the command prompt Give the Hatch command (either form the toolbar or at the command line type: BHATCH) The Hatch pattern dialog will appear. In this box do the following: 1. Click on Patterns to bring up the Hatch Patterns Palette window. 2. Pull bar down until you see earth pattern and then click on it. 3. Click on OK to exit the Hatch Patterns Palette window. 4. Click on the Scale box and enter 12 (very important!). 6. Click on Select objects 6. Select the inside box by selecting each line. 7. Press ENTER to Select objects: prompt 8. Click on Preview hatch. 9. If it looks like the illustration, click on ContInue to return to window. 10. Click on Apply to finish hatch. The result should look like the Illustration (Fig. 4-23). ACAD object snap tutorial Page 6
Note that the BHATCH command will use a fair amount of memory although AutoCAD has decreased the amount of disk space for hatch patterns. But, you should check the size of your drawing after using hatch, just in case. You changed the scale to 12. At the scale of 1, you would probably not see the hatching, as it would be solid. In fact, It might have locked up your computer or given you a Fatal Error kicking you out of AutoCAD! Be sure to preview your hatch to make sure it is the right size. If you are unsure of the scale, specify a much larger scale. You can always scale it down later. Mother aspect of scale is that it is related to your drawing limits. If you set up your drawing for 1/4" = 1' scale, you should use 48 for the scale. If you set up for 1/8" = 1' scale, then you should set scale at 96 and so on. AutoCAD needs an enclosed boundary to complete a hatch. If not, AutoCAD will give up or fill it In Incorrectly. If you have an object or entity within another entity and want to hatch between the two, you can select first the outer boundary and then the internal boundary. AutoCAD will fill the hatch and stop at the boundary as below (Fig. 4-24). 1. Use the BHATCH command or to bring up the dialogue box. 2. Click on Patterns ha 3. Click on another pattern. 4 Check that the Scale box still reads 12. 5. Click on Select objects button. 6. Select the outer circle and the inside diamond as shown (fig. 4-24) 7. Click on "Preview hatch button. 8. If it looks like the illustration, click on Continue to return to window. 9. Click on Apply to finish hatch. ACAD object snap tutorial Page 7
Often you will want to label within the hatch pattern. AutoCAD win hatch around the text creating an Invisible box if you select the text as a boundary. If you do not select the text, AutoCAD will ignore the text and fill in the hatch over it When two entitles overlap, selecting the objects will not work because one object will be filled in completely. In this case, you pick points and AutoCAD will search in all directions from the point to select a boundary. Such is the case with the outer area of the rug design where the outer lines overlap the diamond (fig. 425): At the command line type: BHATCH 1. Click on Patterns to bring up the Hatch Patterns Palette window. 2. Pull bar down until you see earth pattern and then click on it 3. Select another hatch pattern if you want 4. Click on Pick points.. box. 5. Point In areas illustrated in (fig. 4-25). 6. Press ENTER key to get dialogue box back 7. Click on preview Hatch box. 8. After viewing, click on Continue to get dialogue box back 9. Click on Apply to finish hatch. ACAD object snap tutorial Page 8