Houdini 17.0 Nodes VOP nodes

Intersect VOP node

Computes the intersection of a ray with geometry.

This operator computes the intersection of the specified ray with the geometry, and returns the number of the hit primitive or -1. In the case of multiple intersections, the one closest to the ray origin will be used.

If a metaball is hit, the returned primitive number will be the number of primitives in the geometry (to separate this case from that of a miss) as the specific metaball can’t be meaningfully identified.

The uv values are the intrinsic interpolation coordinates for the underlying geometric primitive. For a triangle, they represent the barycentric coordinates of the triangle. For other primitives they may represent other values, such as parametric coordinates. They are not tied to any attribute values.

In order to use these values, you would need to interpolate an attribute for a primitive at the given coordinate. Please see the prim_attribute function, which takes these coordinates for evaluation.

Tip

Intersect will only check for intersections within the maximum length of the Ray Direction - [0, length(raydir)].

Examples

IntersectGrid Example for Intersect VOP node

This example demonstrates how grid points can be transferred to particles on the surface of a sphere using the Intersect VOP.

VOP nodes