Rendering in AutoCAD and Accurender

3d Rendering in AutoCAD R14

The AutoCAD built-in rendering engine:

Lights

There are three types of lights which can be used:

Distant light (like the sun)

To make a brighter scene, make more than one sun (distant light)
Spotlight (shines in a straight line only, and requires a target and a location)
Point light (shines in all directions equally, and only requires a location)

To locate lights in the drawing, before you pick a point for it, type .xy. That will allow you to set the height of the light. Otherwise, all light locations will be placed at the current elevation (usually 0)

Textures

Note that when textures are applied to an object, they are applied to the default surface only, typically the plan (top) of the object.

If you want them to be applied to a wall, you must create a 3dface or a 3dsolid parallel with the wall you want the texture to appear on.
Then select the "Mapping" command from the Render toolbar (or, "View," "Render," "Mapping" from the pull-down menu).
Select the object to map
Select the radio button named "Planar Projection."
Select the "Adjust Coordinates" button
Osnap to the lower left, the lower right, and the upper left corners of the object.
You may want to adjust the scale of the bitmap which will be applied to that object, if it is generally too large or small. To do that, note that the larger the number in the scale, the smaller the pattern will be.

You can change the opacity of the glass texture, but it can be changed only universally, for all glass textures.

You can adjust the scale of a texture either universally (for all objects) (use the library icon) or individually for each object (use the apply texture icon).

You can make your own materials under the apply texture icon by clicking on "New". You can even add images to your texture, but they have to be __.tga files. If you have a file in some other format, you can convert that file to a ___.tga file by opening it in Paint Shop Pro, and then saving it as a tga file.

3d Rendering in AutoCAD R14 using straight AutoCAD

1. Start a new drawing using the A-size template
2. Draw a box for the base using the 3d solid command:

Draw
Solids
Box
<Corner of Box> 0,0,0
<other corner> (pick a point in the upper right hand corner of grid)
Height 1

3. Move it down 1ä

Move
L
0,0,-1 <RET> <RET>

4. Draw another box with a height of 10 feet
5. Draw a 24 foot high cylinder
6. Draw a 36 foot high cone
7. Turn grid off
8. Change base to white color
9. View drawing from SE:

View
3D Viewpoint
SE Isometric
10. View
Render
Light
Distant Light
New
Type ãSUNä in Light Name Box
Check Shadow on
Click Sun Angle Calculator
Click Geographic Location
Click on map at Chicago location
Change date to 4/1
Change time to 10:00
Change time zone to CST
Click OK
Click OK again
Click OK again

11. Save and give drawing a name (perhaps your name)
12. View

Render
Click on word "Render" in white drop-down box and select "Photo Raytrace"
Click box next to "Shadows"
Click on word "Render"

13. View

Render
Materials
Select several materials
Blue Glass
Brown Bumpy Brick
Wood - Dark Ash
Wood - Medium Ash
Wood - White Ash
White Plastic
(hint - you can pick several materials to use by holding the <Ctrl> button down while picking)
Click OK
Click on White Plastic
Click Attach
Pick the base
<RET>
Click Dark Ash
Attach
Pick one of the objects
<RET>
Medium Ash
Attach
Pick another object
<RET>
Light Ash
Attach
Pick the third object
<RET>

14. View

Render
Render
Render

15. Change your viewpoint by using the Dview command

Dview
Select all objects
PO
0,0,0
50',50',50'
D
Slide the cursor to the right or left until you get the right size
CA
Slide cursor around until you get the right point of view, then click the left button of the mouse. This dynamically changes only the camera location, without changing the target. The first changes the altitude and azimuth, the second changes only the azimuth.
At this point you can go back and set the Distance again by typing D<RET>
PA will change your camera and target location without changing the distance.
Z will change the focal length of the camera lens so you can get either telephoto or wide angle views (in effect it changes the ãcone of visionä). It is good to have a wider angle for architectural subjects ö it adds ãdramaä to the drawing.
<RET> will end the perspective program and bring you back to the fa,iliar Command: prompt.

16. Save the perspective view -type V<RET> click on the "NEW" button and type in a name in the slot, and click on OK. This way, you can easily retrieve it again.
17. Save the drawing again
18. Render this view
19. Try changing materials
20. Add another light.

View
Render
Light
In drop-down box click on Spotlight
New
Type name ãSpotä in Light name box
Modify
0,0,0
50',50',5'
Click Shadow On
Click Shadow Options
Shadow Volumes/Ray Traced Shadows
OK
OK
OK

21. Add more lights -try distant light and other times for sun
22. Create Scenes and select certain lights to be used with each scene
23. Make Slides of each rendered scene

MSLIDE
Give it a name

24. Play slides to display sequence of scenes ö perhaps do a sunrise to sunset sequence showing how the building will look at every hour.
25. Do a series of rendered plans

Type Plan<RET><RET>
Render
Make slide

3d Rendering in AutoCAD R14 with Accurender

1. Create new layers of all objects - name them

Base
Object1
Object2
Object3

2. Change each of the objects to be on one of these new layers
3. Type ar3<RET>
4. Click on Materials button
5. Click on Base layer on list, then "Assign Material" button, then pick "AR2_ACCUREND, then pick "dura-glossy, white" from list of materials, then click on OK
6. Assign materials for other 3 layers:

Object1: brick
Object2: bronze, polished
Object3: concrete, pitted, natural tan

7. Click on Lighting button
8. Click on word SUN, then click on the ON button
9. Click on sun again, then edit button
10. Click on place tab
11. Click on Chicago, then click on date and time tab
12. Change month to 4 and day to 1
13. Click on OK then the Close button
14. Click on Raytrace Tab, then the Raytrace button, Exterior Scene, then Full
15. It will take longer to render, but results will be better ö note that it automatically goes into a perspective view, based on your viewpoint
16. You can make slides of this rendering
17. You can increase the quality of the rendering. It is set to "Medium" by default, but increasing it to "Highest" will take much longer (about 15 minutes) to render.
18. You can save the rendering to a JPG file to be able to insert it into a drawing, send it to someone attached to an email message, or upload to your internet site. To do this click on the Settings button, in the drop-down box, select JPG. Note that the name of the JPG file will be the same as your drawing name, unless you change it here. Note that Accurender gives you many more choices of types of graphic files to save as. Straight AutoCAD gives you only one choice -BMP file, which is not as ãclean.ä

How to speed up rendering with AccuRender:

One of the most important jobs of the 3D modeller is to keep the face count down to an absolute minimum. In most cases, a 16 sided polygon will look exactly like a circle - and in some cases 8 will be enough. If the circle is tiny, use a square! In any case, unless you really know how to control the faceting of round objects, don't let AutoCAD and AccuRender do it for you - use lines instead of curves. Think about how many faces you are creating for every object you make. If you make a sheet of glass from an extruded solid, you are creating 12 triangular faces. If you make it from a 3dface, you create only 2 triangular faces. Over a whole building, this can be a massive saving in memory.

Keep your use of raytracing effects to a minimum. By this I mean reflectance, transparency, refraction, depth of field. Only use them if you need them - don't just add 30% reflectance to a material if you feel like it - make sure you will need it - if you can't see the effect in the final rendering, you don't need it.

Procedural materials can get heavy. If you have a granite procedure on top of a blend on top of a mask, and all made into a tile with a granite joint material, the stuff will take ages to render. Use a bitmap instead.

Too many lights in a raytrace-only rendering will cause quite a big slow down. If you have loads of lights, consider radiosity.

Finally, the most obvious one: Don't set your anti-aliasing higher than you need. I believe the consensus is that you will rarely need any higher than the "high" setting. You many find that certain tiled materials look better at higher settings, but in most cases rendering at a higher resolution is a better option. In general you should use "medium" for test runs, and "high" for finals - unless you have a specific reason for the "very high" and "highest" settings.