occluded: Occluded shading color. The default is white.

unoccluded: Unoccluded shading color. The default is black.

numSamples: Controls the number of occlusion samples per camera hit point. The default is 4.

distribution: Sample distribution can be uniform or cosine. The defaul is cosine.

cosineSpread: Sample spread of rays for cosine distribution. The defaul of 1 gives lambertian distribution.

falloff: Falloff values greater than zero create a softer look. The default is 0.

maxDistance: The max distance at which objects may occlude. The default of 0 is infinite.

direction: Trace rays in the direction of the surface normal (outside), inverse to the normal (inside), or in both directions. The default is outside.

biasNormal: Add a directional bias to the normal vector. The default is no bias.

traceSet: Restrict ray tracing to a subset of objects defined by one or more trace groups.

VOP nodes