usdgeom-mesh-manifold#

Code

VG.007

Validator

latest+

Compatibility

core usd

Tags

✅

Summary#

Mesh geometry must be manifold

Description#

Mesh geometry must maintain manifold topology to ensure proper simulation and rendering behavior. Non-manifold issues include:

  • Non-manifold vertices: Vertices are repeated in the geometry

  • Non-manifold edges: Edges are repeated multiple times

  • Inconsistent winding: Polygon winding appears inconsistent

Why is it required?#

  • Memory usage inefficiency

  • Visual artifacts

  • Simulation instability

Examples#

# Invalid: Non-manifold edge
def Mesh "BadMesh" {
    int[] faceVertexCounts = [4, 4]
    int[] faceVertexIndices = [0, 1, 2, 3, 3, 2, 4, 5]  # Edge 2-3 used twice
    point3f[] points = [(0,0,0), (1,0,0), (1,1,0), (0,1,0), (1,2,0), (0,2,0)]
}

# Valid: Manifold mesh
def Mesh "GoodMesh" {
    int[] faceVertexCounts = [4]
    int[] faceVertexIndices = [0, 1, 2, 3]
    point3f[] points = [(0,0,0), (1,0,0), (1,1,0), (0,1,0)]
}

How to comply#

  • Use mesh repair tools to weld edges and vertices

  • Fill holes in geometry

  • Align face normals

  • Reconvert to USD after repair

  • Scene Optimizer - Remesher

For More Information#