Houdini 16.5 Nodes VOP nodes

Dirt Mask

Masks crevices or exposed edges

When the unmodified surface normal, will find crevices. If the negated normal is connected, will find exposed edges. @parameters

Sampling Mode

Hemisphere

Samples in a dome around the shaded point. The dirt mask is computed using the percentage of rays that hit a surface.

Fan

Samples in a fan around the surface normal, with Sensitivity controlling the ray direction. Lower sensitivity values rotate the rays towards the surface normal.

The mask is computed based on the farthest surface hit by any ray.

Sensitivity

In Fan Sampling Mode, this controls the ray direction. Lower sensitivity values rotate the rays towards the surface normal, making it less likely that neighbouring surface points are hit.

Samples

The number of samples to take.

Maximum Distance

The maximum distance to cast rays.

Modulate this using a noise function to create dirty areas of varying size and shape.

Bias Direction

A direction in which to bias rays. For example, this can be used to simulate more dirt accumulating on the underside of an object.

Bias

The amount to bias rays in the Bias Direction

Scope

This can be used to limit the set of objects to cast rays against.

Inputs

P

The surface position from which rays are cast.

nN

The surface normal. This can be inverted to mask exposed edges rather than crevices.

VOP nodes