Copy Mesh: Error: Cannot connect disconnected graphs.

[marwie]

I'm currently experimenting with creating a new GLB on the fly and copying some of the meshes to the new GLB for processing.

Currently having this code which however results in Cannot connect disconnected graphs

Any hints on why this happens/can be fixed would be greatly appreciated :)

const newDoc = new Document();
	newDoc.createScene();
	newDoc.createBuffer();

	const node = newDoc.createNode();

	const newMesh = newDoc.createMesh();
	node.setMesh(newMesh);

	newMesh.setName(mesh.getName());
	newMesh.copy(mesh);

[donmccurdy]

I think the issue is with this line:

newMesh.copy(mesh);

... I assume mesh is part of a different Document than newMesh? The implementation of .copy() involves having the destination mesh assign itself references to the primitives of the source mesh, which refer to accessors, which refer to buffers ... and these resources can't be shared by two Documents.

Something like the proposal in #924 might get you closer.

[marwie]

Ok newMesh.copy(mesh, (p) => p.clone()); still results in the same error unfortunately

[donmccurdy]

I think the workaround i suggested in the post above (before editing it out ...) was incorrect sorry! The implementation of document.clone() is not a one-liner, but extracting bits of that should work, and it basically involves copying or reconstructing the primitives and attributes first, then doing a copy() on the mesh with a callback that returns the equivalent primitives from the new document. Not necessarily simpler than manually rebuilding the mesh at that point, though.

[marwie]

Thanks for the pointer. I got a lot closer (currently manually copying the mesh/primitive/accessors) - just got to figure out what "message": "Entity cannot be empty." in my output GLB is referring to

[marwie]

Ah - i just missed adding the node to the scene :)

[marwie]

happy with the result for a quick hack - thanks again :)