Houdini 20.0 Nodes Geometry nodes

UV Autoseam geometry node

Generates an edge group representing suggested seams for flattening a polygon model in UV space.

Since 17.0



When this is blank, the node applies to all geometry in the input. You can enter the name of a primitive group, or specify primitives using group syntax to operate on only a subset of primitives.

Enforce cuts

Include edges

Always include edges in this group as seams.

Island attribute

The name of an integer primitive attribute. If this is not blank, polygons with the same value for this attribute are treated as UV islands, and the edges across which the value is different are treated as seams.

Avoid cuts

Exclude edges

The node will not turn edges in this group into seams.

Avoid attribute

The name of a float point attribute. If this is not blank, the node will attempt to avoid cutting points with a value greater than 0, with higher values making the node try harder to avoid the point.


A scaling factor for the values in the Avoid attribute.

Grain islands

UV Autoseam works by starting from a set of small “grain” seed islands and merging them up to get the larger islands.


Curvature Based

Use the local properties of the mesh (such as curvature) to produce initial grain islands.

Existing Islands

Use existing UV islands in the input as the starting point.

Grain tolerance

When Splitting is “Curvature based”, controls how sensitive grains are to changes in normal direction across surfaces. A value of zero is very sensitive and produces tiny grains. Larger values up to 1 are less sensitive and produce larger grains.

Merge threshold

Controls how often smaller grains merge to become larger islands. 0 never merges (giving the initial grains as output), 1 merges all connected grains together (giving no seams in the output). You can tweak this control, centering around 0.5, to get more or fewer seams.

UV Attribute

When Splitting is “Existing islands”, the UV attribute from which to get the islands. This is usually uv.

Connectivity Tolerance

When Splitting is “Existing islands”, the maximum difference between attribute values across the end points of an edge that determine an existing seam.

Output groups and attributes

Seams Group Name

Outputs the computed seams in an edge group with this name.

Island Attribute

Adds an attribute to the polygons containing the number of the island the polygon was in.

Geometry nodes