MeshType

Changes between polygon and subdivision representations for mesh objects, and optionally recalculates vertex normals for polygon meshes.

Note that currently the Gaffer viewport does not display subdivision meshes with smoothing, so the results of using this node will not be seen until a render is performed.

user

Container for user-defined plugs. Nodes should never make their own plugs here, so users are free to do as they wish.

enabled

The on/off state of the node. When it is off, the node outputs the input scene unchanged.

filter

The filter used to control which parts of the scene are processed. A Filter node should be connected here.

meshType

The interpolation type to apply to the mesh.

calculatePolygonNormals

Causes new vertex normals to be calculated for polygon meshes. Has no effect for subdivision surfaces, since those are naturally smooth and do not require surface normals. Vertex normals are represented as primitive variables named “N”.

overwriteExistingNormals

By default, vertex normals will only be calculated for polygon meshes which don’t already have them. Turning this on will force new normals to be calculated even for meshes which had them already.

interpolateBoundary

Specifies which parts of mesh boundaries are forced to exactly meet the boundary. Without this forcing, a subdivision surface will naturally shrink back from the boundary as it smooths out.

Usually, you want to force both edges and corners to exactly meet the boundary. The main reasons to change this are to use Edge Only if you want to produce curved edges from polygonal boundaries, or to use None if you’re doing something tricky with seamlessly splitting subdiv meshes by providing the split meshes with a border of shared polygons in order to get continuous tangents.

faceVaryingLinearInterpolation

Specifies where face varying primitive variables should use a simple linear interpolation instead of being smoothed.

In order for UVs to correspond to approximately the same texture areas as the original polygons, usually you want to, at minimum, pin the outside corners. But pinning the entire boundary causes some pretty weird discontinuities, so finding the right compromise is tricky.

See the OpenSubdiv docs for explanation of the details of options like Corners Plus 1: https://graphics.pixar.com/opensubdiv/docs/subdivision_surfaces.html#schemes-and-options

triangleSubdivisionRule

Option to use a non-standard Smooth subdivision rule that provides slightly better results at triangular faces in Catmull-Clark meshes than the standard Catmull-Clark algorithm.