Provide documentation on draco3d vs draco3dgltf packages?

[donmccurdy]

From the information in the README it would be difficult to know that both packages exist, or to know what they each do. I'm still not sure what (if anything) happens if thedraco3d is used to create a glTF file instead of the draco3dgltf package... could the intention for each package be documented?

[tomfinegan]

I think we finally cleared this up:

• draco3d: all Draco features.
• draco3dgltf: Only the features of Draco that are included in the Draco GLTF spec.

The build system variable has been renamed, and the help text updated to hopefully help keep this clear in the future. Please feel free to reopen if more discussion or clarification is needed.

[donmccurdy]

That's really helpful, thank you! I think if some wording could be added to the draco3dgltf npm package description, particularly emphasizing that it is a subset of the draco3d package, that would be a good clarification. I'd assumed it was a fork with some slightly different behavior, and have seen users assume that it is a superset including functionality related to reading/writing glTF files. Perhaps:

The draco3dgltf package is a subset of the draco3d package, containing only features of the Draco library that are relevant to compression in the glTF file format. glTF files (.gltf, .glb) can contain Draco-compressed mesh geometry, as defined by the glTF extension KHR_draco_mesh_compression.

I might also go one step further and include:

This library does not directly read/write glTF files, but is intended for use within tools and applications that deal with the glTF format. Examples of tools using the Draco library to apply compression to glTF files include: Blender, glTF Transform, and glTF Pipeline.

[tomfinegan]

@donmccurdy The description update will be in the next push. Thanks for the suggested text!