Houdini 21.0 Nodes Geometry nodes

Labs Auto UV geometry node

Automatically generates UV attributes using one of multiple algorithmic methods.

The Labs Auto UV SOP provides several methods for generating UV layouts on polygonal geometry. It analyzes curvature, surface orientation, and spatial relationships to create UV seams, islands, and packed layouts suitable for real-time and offline workflows.

Parameters

Group

The group of primitives to apply the UV unwrap.

Method

UV Attribute

The name of the output UV attribute.

Method

The algorithm used to generate the UVs.

Shortest Path

Identifies regions of high curvature and computes shortest paths between them to define UV seams.

Cluster

Clusters primitives based on spatial position and normal orientation to generate UV islands.

UV Unwrap

Uses the built-in UV Unwrap SOP to generate UVs. While not always optimal on its own, this method is often effective when combined with Merge Small Islands.

UV AutoSeam

Uses the UV Autoseam SOP to generate seams automatically.

Shortest Path

Collapse Distance

Fuse threshold used when computed paths are too close together.

Number of Paths

Number of high-curvature points used as path endpoints.

Convex Multiplier

Biases seam placement toward highly convex regions. Useful for hard-surface geometry.

Occlusion Multiplier

Biases seam placement toward regions of high ambient occlusion. Useful for organic geometry.

Cluster

Number of Clusters

Number of UV islands to generate.

Normal Blur

Amount of normal blurring applied when evaluating similarity. Higher values merge nearby islands.

Random Seed

Seed used to vary the clustering result.

UV Unwrap

Planes

Number of projection planes used for unwrapping.

UV AutoSeam

Grain Tolerance

Sensitivity to changes in normal direction when splitting by curvature. Lower values produce smaller grains. Higher values produce larger grains.

Merge Threshold

Controls how aggressively adjacent grains merge. A value of 0 preserves all grains. A value of 1 merges all connected grains into a single island.

Packing Options

Merge Small Islands

Merges small UV islands into neighboring larger islands.

Small Island Cutoff

Size threshold below which islands are considered small and eligible for merging.

Optimize UV Border

Attempts to clean up triangles along island borders. May cause small islands to reappear.

Flattening Method

The method used to flatten UV islands.

Island Rotation Step

How UV islands are rotated during packing.

Packing Iterations

Number of packing attempts used to fit islands together.

Island Padding

Padding applied between UV islands, in pixels.

Padding Resolution

Reference resolution used to compute Island Padding.

UDIM Target Tile

The UDIM tile used as the starting location for the generated UVs. The generated UV layout is offset so that the first island begins in the specified UDIM tile (for example, 1001).

Geometry nodes