3ds Max 2012 Bible - Kelly L. Murdock [247]
Shadow parameters
All light types have a Shadow Parameters rollout that you can use to select a shadow color by clicking the color swatch. The default color is black. The Dens setting stands for “Density” and controls how dark the shadow appears. Lower values produce light shadows, and higher values produce dark shadows. This value can also be negative.
The Map option, like the Projection Map, can be used to project a map along with the shadow color. The Light Affects Shadow Color option alters the Shadow Color by blending it with the light color if selected.
In the Atmosphere Shadows section, the On button lets you determine whether atmospheric effects, such as fog, can cast shadows. You can also control the Opacity and the degree to which atmospheric colors blend with the Shadow Color.
When you select a light and open the Modify panel, one additional rollout is available: the Atmospheres and Effects rollout. This rollout is a shortcut to the Environment dialog box, where you can specify atmospheric effects such as fog and volume lights.
Note
The only effects that can be used with lights are Volume Light and Lens Effects. •
Cross-Reference
Chapter 46, “Using Atmospheric and Render Effects,” covers atmospheric effects. •
If the Area Shadows option is selected in the General Parameters rollout, then the Area Shadows rollout appears, which includes several settings for controlling this shadow type. In the drop-down list at the top of the rollout, you can select from several Basic Options, including Simple, Rectangle Light, Disc Light, Box 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. •
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 process. 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