Houdini 17.0 Nodes VOP nodes

Hair Specular VOP node

Generates a color specifically for curves (hairs) using a specular lighting model calculation.

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

Inputs

nN

This normal should be the explicitly connected to the specially calculated hair normal VOP. In this VOP the normal is already front facing and normalized.

nI

The incident direction ray used in the hair 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.

nT

This is the vector tangent to the curve (hair). If this is not connected, the normalized global variable, dPdt, is used. If the tangent vector is connected as an input, it must be normalized.

Ks

The specular intensity. A value used to darken or lighten specular highlight.

spec

The specular highlight color. For hair, a value slightly lighter and less saturated than the hair tip color is recommended.

rough

A floating point value to control the width of the specular highlight along the curve (hair).

Outputs

color

The hair specular color highlight.

Ks * spec * hairspec(nN, -nI, nT, rough)

illum

Just hair specular lighting without the multiplication by the specular intensity and color. Usually used as an export parameter for extra images planes used in the composite of the final image.

bsdf

Returns the PBR wireblinn function calculation.

Ks * spec * wireblinn(nT, 4/rough)

Examples

The following examples include this node.

FurBallWorkflow Example for Fur geometry node

This example demonstrates how the Fur SOP and Mantra Fur Procedural can be applied to an animated skin geometry. CVEX shaders are used to apply a custom look to the hairs based upon attributes assigned to the geometry.

FurPipelineExample Example for Fur geometry node

This example illustrates how custom shaders can be used to define the appearance of fur generated by the Fur SOP.

See also

VOP nodes