The ilrSurfaceThickness node is a utility node that samples the distance to occluding geometry behind the sample point. This value could be used for simple sub surface scattering effects or for any purpose in any general shading network. There are a number of ways to sample the thickness, either with one ray to get a single measurement, or to send a number of rays in a cone, to get a weighted measurement.
Defines how many rays to send to sample the thickness.
Defines how large cone to sample in. 0 degrees is a single ray, 180 degrees is a full hemisphere.
Defines how far a ray is allowed to go before it is considered to be infinite.
Flips the direction of the sample rays. If the normals are pointing inwards, this check box must be unchecked.
Normally the samples are sent along the surface normal, but if this check box is enabled, the sample rays are sent in the incoming ray direction.
Scales the output with Maximum Ray Distance.