How to Extrude & Cap a path that come back internally

Hi, I’m trying to extrude and cap the following shape.
It seem to have a problem with capping when the path goes internally in the shape.

I would expect the cap to follow the path instead cutting through it.
Does someone know why it have this behavior? How can I only extrude the path without having the cap cutting through the shape?

Here’s the code.
Unfortunately, the path is too long to be pasted here.

export function pathToMesh(path:Path, extrusion:Vector3 = new Vector3(0, 0, 10)):Mesh {
  const extrusionPath = [
    new Vector3(0, 0, 0),
  const pathVec = pathToVector3(path)

  const mesh = MeshBuilder.ExtrudeShape('extrusion', {
    shape: pathVec,
    path: extrusionPath,
    cap: Mesh.CAP_START,
    sideOrientation: Mesh.DOUBLESIDE

  return mesh


Hi @samuelint and welcome to the community. The way caps are created they cannot work with concave paths. Try this instead


Thanks @JohnK!

MeshBuilder.ExtrudePolygon did what I expect.

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