gltf-pipeline runs out of memory for very large glTF

[likangning93]

Running a very large (~10 million triangles, 1 GB buffer) model through gltf-pipeline can cause the pipeline to run out of memory even when running with max-old-space-size set to something large like 16 GB. This seems to happen during the optimizeForVertexCache stage.

[likangning93]

Not really something we expect to effect every day users - models that large shouldn't be optimized for vertex cache because they aren't really drawable anyway and should be split up (which is what 3D Tiles is for). But we should document this anyway - who knows, maybe someday we can even open a PR that closes this!

[lilleyse]

I'm curious to see what happens now. If you still have a model that large lying around I'd like to try it out.