Houdini 17.5 Nodes VOP nodes

Fresnel VOP node

Computes the Fresnel reflection/refraction contributions given a normalized incident ray, a normalized surface normal, and an index of refraction.

The amount of reflected light will be returned in kr, and the amount of transmitted light will be returned in kt. Optionally, the reflection and transmission vectors can be returned in the R and T variables. Both R and T will be normalized.

The global variables I and N will be used if the incident vector and surface normal inputs are not connected. If connected, the N and I vectors must be normalized.


The following examples include this node.


This example demonstrates the use of ramps and referenced ramps which are animated over time.

See also

VOP nodes