KHR_draco_mesh_compression and triangle strips

[bghgary]

It seems like Draco does not support triangles strips: google/draco#423, but yet, the KHR_draco_mesh_compression spec explicitly states that it is supported.

How should implementations handle this?

[donmccurdy]

It's not obvious to me what (if anything?) is missing for the sequential encoder to support triangle strips, but I gave it a quick test and hit generic errors. three.js does not do any special workaround here, and basically trusts that the vertex and index data returned by the decoder are what the glTF header says that they are. glTF Transform will skip Draco compression for any mode but plain triangles.