MergeMeshes flips normals of some submeshes some of the time

Trying to refactor an old project of mine from Babylon 2.x to 5.x, i am noticing that when using MergeMeshes(), some submeshes of the resultant mesh have their normals flipped.

After asking ChatGPT about it, it suggested to use .computeNormals(). this resulted in either fixing the issue or flipping the normals of all submeshes. Is there another solution I might try?

Sorry I can’t easily provide a sandbox because I don’t know how to import my assetfiles into the sandbox. Perhaps interesting of note is that babylon 2.x did not have this issue since I don’t remember running into it before.

Hello! A playground would definitely be helpful, see here Using External Assets In the Playground | Babylon.js Documentation ( for how to use external assets