Houdini 20.0 Nodes VOP nodes

Normal Clamp VOP node

Clamp shading normals to prevent bad reflection directions

On this page
Since 16.5

Clamps the input shading normal in a way that reflection vector of the input incident direction (assuming perfect specular) lies on the same side as geometry normal. This VOP can be used to avoid shading artifacts at grazing angles particularly when bump or normal maps are used.


Shading Normal

Normalized shading normal.

Geometry Normal

Normalized geometry normal.

Incident Direction

Normalized direction from eye to shading point.


Effectively increases detection threshold. If bias is set too high, reflections near grazing angles may appear incorrect.



The clamped shading normal (normalized).

See also

VOP nodes