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whether to render, save to a .mi file, or both, are on the Translator Options
on page 6122 rollout.
To make the mental ray Renderer the default renderer for new scenes:
■ After you make the mental ray renderer the active production renderer,
click Save As Defaults on the Assign Renderer rollout.
Getting Good Results with mental ray Rendering
Although the mental ray renderer is relatively easy to use once you’ve set it
up correctly, there are several "gotchas" that you might encounter immediately,
especially if you’re primarily accustomed to the 3ds Max scanline renderer
and its workflow. For example, see
3ds Max Materials in mental ray Renderings
on page 6048 . Below are some basic rules of thumb for using mental ray in 3ds
Max.
Using Lights with the mental ray Renderer
When you set up a scene for rendering with the mental ray renderer, keep the
following tips in mind:
■ The Overshoot parameter for lights doesn't work when you use mental ray
to render shadow-mapped shadows. To use Overshoot, use ray-traced
shadows.
■ Excluding an object from shadow casting doesn't work when you use
mental ray to render shadow-mapped shadows. To exclude objects from
shadow casting, use ray-traced shadows. (The Exclude button is on a light's
General Parameters rollout.)
■ When you assign a map to object shadows in the light's Shadow Parameters
rollout, the mental ray renderer does not recognize the toggle for the map
(to the left of the Map button), and renders the map whether the toggle
is on or off. To stop using the map, you must click the Map button and in
the Material/Map Browser, assign NONE as the map type.
■ Using the default scanline renderer, you can set a light to have a value of
zero, with a shadow color of white, and a shadow density of −1. With these
settings, the light casts shadows but does not illuminate the scene. To get
the same effect using the mental ray renderer, the light value must not be
zero. Instead, set it to a value close to zero (for example, 0.001 or –0.001).
6044 | Chapter 18 Rendering