Convert `iiwa7` and `iiwa14` .obj mesh files to glTF

siddancha commented 4 months ago

Changes

Replaces iiwa7 and iiwa14 .obj mesh files (visual only, not collision) to .gltf + .bin files.
- For example, link_0.obj now becomes link_0.gltf + link_0.bin.
~~Also adds draco compressed versions of the files.~~
- ~~For example, link_0.obj also becomes link_0.draco.gltf + link_0.draco.bin.~~

Benefits

This resolves the issue of IIWA *.obj files being duplicated in static HTML: https://github.com/RobotLocomotion/drake/issues/21056
This also helps reduce the size of link_0.obj (620 KB) to
- link_0.gltf (4 KB) + link_0.bin (184 K) or
- ~~link_0.draco.gltf (4 KB) + link_0.draco.bin (20 KB)~~

Visualization

Here's a visualization of what the IIWA's look like: [ANIMATION]:

Conversion process

The following script was used for conversion using the obj2gltf ~~and gltf-pipeline tools~~:

FILES="path/to/*.obj"
for file in $FILES; do
  obj2gltf -i "${file}" -s --inputUpAxis Z
  # obj2gltf -i "${file}" -o "${file%.obj}.full.gltf" --inputUpAxis Z
  # gltf-pipeline -i "${file%.obj}.full.gltf" -o "${file%.obj}.draco.gltf" -d -s
  # rm "${file%.obj}.full.gltf"
done

This change is

jwnimmer-tri commented 4 months ago

Thanks for this!

At the moment, we can't accept the draco files, even as as separate *.gltf files. We intended to use this repository to showcase the best practices for Drake's model files, and having duplicated *.gltf files (depending on the mesh compression) is not a best practice.

Our medium-term aim with draco meshes is to have them as "extentionsUsed" but not "extentionsRequired" in the same gltf file as the uncompressed meshes. Then consumers that know about draco will use them, but consumers that don't will fall back to the uncompressed mesh. A kind of "graceful degradation" so that we don't need (for example) separately forked SDFormat files for the two mesh styles.

So I'll ask that for this first PR, please just keep the normal uncompressed meshes and git rm the draco ones for now. Once we have more Drake capabilities and tooling related to draco meshes ready, we can start using draco here.

siddancha commented 4 months ago

Makes sense @jwnimmer-tri . Removed all draco-related files.

siddancha commented 4 months ago

@jwnimmer-tri I want to add that I tweaked some material parameters in the glTF files. For one, the original .obj files don't contain any material/color information. I copied the RGB values provided in RobotLocomotion/drake's iiwa_description URDF files. Since material properties in glTF files are more expressive (e.g. metallicFactor, roughnessFactor), I picked sensible values guided by how aesthetic the iiwas looked in meshcat.

RobotLocomotion / models