Autodesk 12812-051462-9011 - 3DS MAX 9 COM LEGACY SLM, Help File

Page: 2386 / 2577

Skylight and Radiosity in Architectural Design
In order for radiosity to be processed correctly when a Skylight is added to
the scene, you need to make sure that walls have closed corners and floors
and ceilings have thickness under and over the walls. In essence, your 3D
model should be built just like the real-world structure is built.
If you build your model with walls that meet along a single edge or floors and
ceilings are simple planes, when you process radiosity after adding a Skylight,
you can end up with “light leaks” along those edges.
Some of the ways to repair a model so light leaks do not occur are as follows:
■ Make sure floors and ceilings have thickness.
You can fix this by extruding those surfaces at a sub-object level or by
applying modifiers like
Shell on page 1660 or Extrude on page 1448.
■ Use the Wall command on page 516 to create walls.
The Wall command is programmed to make sure corners are constructed
of solid objects instead of leaving a single, thin edge.
■ Ensure that floor and ceiling objects extend beyond walls.
Floor objects need to extend under walls and ceilings need to extend over
walls.
By building your 3D model using these guidelines, light leaks will not occur
when you process radiosity after adding a Skylight to the scene.
Using Render Elements with a Skylight
If you use Render Elements on page 6336 to output the lighting element on page
6356 of a skylight in a scene using either radiosity or the light tracer, you cannot
separate the direct, indirect, and shadow channels of the light. All three
elements of the skylight lighting are output to the Indirect Light channel.
Procedures
To create a Skylight:
1 On the Create panel, click Lights.
Standard is the default choice of light type.
2 In the Object Type rollout, click Skylight.
3 Click a viewport.
Standard Lights | 5067