Houdini 20.5 Nodes Geometry nodes

Intersection Analysis geometry node

Creates points with attributes at intersections between triangles and/or polygon curves, either within a single input geometry or between a first and a second input geometry.

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Since 16.0

This low-level node can be used to build higher-level tools dealing with intersecting geometry, such as the Boolean node. If you just want to intersect geometry or output intersections in a more usable format, use Boolean.

The node outputs a point at each intersection with attributes identifying the origin of the intersection. It does not pipe through the input geometry. You can control which attributes the node creates on the points using the Input number, Primitive number, Primitive UVW, and Point num parameters.

IMPORTANT NOTE: This node produces correct results only for geometry that consists of linear pieces, specifically triangles and polygon curves. Curved geometry such as NURBS is not supported. Each closed polygon in the input must be a triangle. Each open polygon is treated as a polyline, consisting of multiple line segments. Any other geometry types will produce incorrect results!

Inputs

  • If you connect one input, the node finds self-intersections in the input.

  • If you connect the first and second input, the node finds intersections between the two models.

Parameters

Group A

A list of primitives to check from the first input. If this is blank, the node checks all primitives.

Group B

A list of primitives to check from the second input. If this is blank, the node checks all primitives.

Output attributes

Turn on the checkbox next to a parameter to create the attribute on the output points. You can use the text boxes to change the names of the attributes.

Input Number

Add an attribute indicating which input (0 or 1) the intersected primitive belongs to.

Primitive Number

Add an attribute indicating the numbers of primitives incident to the intersection point.

Primitive UVW

Add an attribute indicating the coordinates of the intersection point in the parameter space of the primitive on which it was generated.

Point Num

Add an attribute indicating the point numbers of points incident to the intersection point.

See also

Geometry nodes