Page 600 - Kitab3DsMax

Part IV: Materials, Cameras, and Lighting Basics

Light, and Sphere Light. You can select dimensions depending on which option is selected. You can also set
the Integrity, Quality, Spread, Bias, and Jitter amounts.
For the Shadow Map option, the Shadow Map Params rollout includes values for the Bias, Size, and Sample
Range. The Sample Range value softens the shadow edges. You can also select to use an Absolute Map Bias
and 2 Sided Shadows.
If the Ray Traced Shadows option is selected in the Shadow Parameters rollout, the Ray Traced Shadows
Parameters rollout appears below it. This simple rollout includes only two values: Bias and Max Quadtree
Depth. The Bias settings cause the shadow to move toward or away from the object that casts the shadow.
The Max Quadtree Depth determines the accuracy of the shadows by controlling how long the ray paths are
followed. There is also an option to enable 2 Sided Shadows, which enables both sides of a face to cast
shadows, including backfacing objects.
For the Advanced Raytraced Shadows options, the rollout includes many more options, including Simple,
1-Pass, or 2-Pass Anti-aliasing. This rollout also includes the same quality values found in the Area Shadows
rollout.

Note
Depending on the number of objects in your scene, shadows can take a long time to render. Enabling raytraced
shadows for a complex scene can greatly increase the render time. n

Optimizing lights
If you select either the Area Shadows type or the Advanced Raytracing Shadows type, then a separate
Optimizations rollout appears. This rollout includes settings that help speed up the shadow rendering pro-
cess. Using this rollout, you can enable Transparent Shadows. You can also specify a color that is used at
the Anti-aliasing Threshold. You can also turn off anti-aliasing for materials that have SuperSampling or
Reflection/Refraction enabled. Or you can have the shadow renderer skip coplanar faces with a given
threshold.

Manipulating Hotspot and Falloff cones
When the Select and Manipulate mode is enabled on the main toolbar, the end of the Hotspot and Falloff
cones appear green for a selected spotlight. When you move the mouse over these lines, the lines turn red,
allowing you to drag the lines and make the Hotspot and/or Falloff angle values greater. These manipulators
provide visual feedback as you resize the spotlight cone.

Photometric light parameters
Several of the light rollouts for photometric lights are the same as those for the standard lights, but several
key parameters are unique for photometric lights, such as the ability to choose a light distribution model
and a shape type.
Distribution options
The Distribution options are listed in a drop-down list in the General rollout. Both Free and Target photo-
metric lights can be set to one of four distribution types. Each of these types appears as a different icon in
the viewports:
l Uniform Spherical: This distribution type emanates light equally in all directions from a central
point, like the standard Omni light.

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