PxrDirt renders local geometric occlusion. This is usef= ul for applying shading effects to nooks and crevices.
A traditional ambient occlusion effect can be accomplished by setting th= e occluded color to black and unoccluded color to white.
Resulting colors for occluded and unoccluded shading.
Controls the number of occlusion samples per camera hit point. More samp= les reduces can the noise at the cost of increased render time.
Possible values are uniform and cosine (Lambertian).
Description | |
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Uniform | Rays are not weighted in any particular directio= n in the hemisphere above the shading point. |
Cosine | Cosine distribution is commonly used to render a= mbient occlusion. |
Sample spread of rays when using cosine distribution. A value o= f 1.0 gives a perfect Lambertian distribution.
Falloff can be used to control the softness of the occlusion effect.
The max distance at which objects may occlude. Zero is infinite (all obj= ects occlude).
Trace rays in the direction of the surface normal (outside), in= verse to the normal (inside), or in both directions.
Add a directional bias to the normal vector. Values must be specified in= world space.
Name of bias direction co-ordinate system transform such as object, worl= d or camera
Restrict ray tracing to a subset of objects defined by one or more trace= groups