Houdini 16.5 Nodes VOP nodes

Specular VOP node

Generates a color using the selected specular lighting model calculation.

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This VOP uses the selected specular lighting model calculation to generate a color. Typically, adding this lighting model into the network, is the last thing done before connecting the resulting color to the output Cf input.

The available specular lighting models are

Inputs

nN

The normal vector is used in the selected specular calculation. The normal should be normalized if explicitly connected as an input. The face forward calculation is optional, but it is recommended. Implicitly, the normalized global variable, N, is used.

nI

The incidence direction ray used in the selected specular calculation, as well as, the face forward calculation. The incident vector should be normalized if explicitly connected as an input. Implicitly, the normalized global variable, I, is used.

Ks

The specular intensity. It is used to darken or lighten the highlight color.

spec

The specular highlight color. It is multiplied by the light color.

urough

This value is used to control the size or spread of the specular highlight.

vough

This is used only if Anisotropic specular is selected. This value controls the size or spread in the V direction of the specular highlight. If urough and vrough are the same, the highlight becomes isotropic, round rather than elliptical. Anisotropic specular is often used in metallic materials.

sharp

This value is used to control the sharpness of the edge of the specular highlight. This is used only if Glossy specular is selected. Glossy specular is used for the cornea of the eye, as well glass and other highly reflective materials.

facefwd

This toggle will change the normal to face forward towards the camera. It is recommended this toggle be on.

Outputs

Color

The selected specular color highlight calculation.

Ks * spec * specularFunction(nN, -nI, urough, vrough, sharp)

Illum

Just selected specular lighting without the multiplication by the specular intensity or the specular color. Usually used as an export parameter for extra images planes used in the composite.

BSDF

The PBR specular calculation.

See also

VOP nodes