Extract selected faces / vertices as an additional submesh

Questions
1

So, I have a mesh containing 4 subMeshes. I know the indices that I wish to extract and create as a 5th submesh with a new material but can’t quite work out how best to go about this. Any suggestions would be very welcome!

2

You can simply call the SubMesh constructor and pass the required parameters:

image

You will have to update the index buffer first. You can do something like this (not tested!):

const ib = mesh.getIndices();
const idxStart = ib.length;
// add the new faces
ib.push(...);
mesh.setIndices(ib);
new BABYLON.SubMesh(0, 0, mesh.getTotalVertices(), idxStart, ib.length - idxStart, mesh);