Houdini 21.0 Nodes Geometry nodes

Labs Quadrangulate 2.0 geometry node

Converts triangulated meshes back into a quad-dominant topology by collapsing diagonal edges and repairing resulting N-gons.

The Labs Quadrangulate SOP identifies and collapses diagonal edges created during triangulation to approximate the original quad layout of a mesh.

The process consists of two stages:

  1. Reduction Stage — Identifies diagonal edges in triangulated quads and collapses them. This can be performed iteratively or by assuming a consistent vertex order.

  2. Refinement Stage — Repairs polygons with more than four vertices that result from edge removal. These regions can be resolved through quadrilateral PolyFill operations or through iterative subdivision until only quads or triangles remain.

This workflow restores quad structure while avoiding silhouette loss when desired.

Parameters

Reduction Method

Method

The method used to identify edges for collapse.

Vertex Order

Collapses every Nth diagonal edge based on vertex ordering.

Longest Edge

Iteratively collapses the longest edges until only quads remain.

Edge to Collapse

Specifies which edge of each triangle is collapsed when Method is set to Vertex Order. Options correspond to the 1st, 2nd, or 3rd edge in vertex order.

Protect Silhouette

Prevents collapsing edges that would alter the mesh silhouette.

Normal Angle

The angle between adjacent polygons used to detect silhouette-breaking edges when Protect Silhouette is turned on.

Refine Method

Refine Method

The method used to resolve N-gons created by edge removal.

PolyFill

Fills N-gons using the PolyFill quadrilateral generation method.

Iterative Divide

Iteratively divides N-gons until only quads or triangles remain.

Fallback Fill Mode

Fallback strategy used when PolyFill quadrilateral generation fails.

Edge to Dissolve

Determines which edges are dissolved when Refine Method is set to Iterative Divide.

Geometry nodes