Graphics Programs Reference
In-Depth Information
Figure 23-1:
Rendering compared to Conceptual visual style.
Before rendering a 3D model, you need to do the following:
Add lighting to highlight features and define shadows
Apply materials to 3D objects by face, object, or layer
Set up a background for your 3D model to be rendered against
All the above-mentioned items help to bring realism to a 3D model. This chapter focuses
on each of these tasks before covering the steps to create a rendering.
Adding Lighting
One of the key ingredients in the soup that makes a rendering look good is
lighting
.
Lighting helps give a model depth through the use of highlights and shadows. Just as in
the real world, objects that are closest to the light source appear the brightest and
those the farthest away appear the darkest.
The two types of lighting in AutoCAD are default and user-defined. Default lighting, as its
name suggests, is on and available in every drawing, and it's what gives some basic form
to your 3D model when you click the Render button before you add lighting of your own.
All types of user-defined lights can cast shadows. Most of the tools that you use to cre-
ate and edit lights are located on the Lights and Sun & Location panels on the Render
tab.
Default lighting
Over the past few years, AutoCAD's default lighting has improved in quality. Prior to
AutoCAD 2007, default lighting consisted of a single distant light source, always directed
toward the target of your current view from behind your back. AutoCAD 2007 added a
