Half Edge Structure for Custom Models.

[T4G2]

As I was working on my bachelor thesis, I needed to create a Half Edge Structure for any given model. I had problems that I had no way to access already created HalfEdge Class in /examples/jsm/math/ConvexHull.js. Also the problem is that this structure is only used in ConvexHull.js however it could be used to create HalfEdge structure from any 3D Model. ) Describe the solution you'd like

• I suggest to move HalfEdge Class to new file HalfEdge.js.
• Create a new Class HalfEdgeStructure with this very simple structure

  this.mesh = mesh
  this.halfEdgeMap = new **Map()**

This Issue is related to following Issue: OBJLoader loses information about Vertex ID. #24361

[LeviPesin]

Can you please file a PR?

[Mugen87]

Moving HalfEdge is fine however it will break the examples/js code path. Besides, I don't think adding HalfEdgeStructure without a concrete use case in the library makes sense.

[T4G2]

Well @Mugen87 , I'm right now using this HalfEdge Structure to implement MMP Algorithm to find geodesics, so I may be able to Push this algorithm as well

[Mugen87]

see https://github.com/mrdoob/three.js/issues/24359#issuecomment-1188847789

It's probably better if your code is put into a separate repository.

[erasta]

Excuse me for intervening, but I also needed the HalfEdge and Face classes from ConvexHull.js, but since they're not exported, i had to copy them to my own repo. Would it be possible to export those by changing the last line? from export { ConvexHull }; to export { ConvexHull, Face, HalfEdge, VertexNode, VertexList }; This will also better reflect the documentation, as those classes are shown there. Thank you.

[Mugen87]

Exporting these classes is okay. Would you like to make a PR?

[erasta]

Yes, thank you, will do shortly.