Mesh warnings from franka_description with recent Drake versions

jwnimmer-tri commented 1 year ago

What happened?

In drake/manipulation/models/franka_description/urdf we provide some sample URDFs for the Franka Panda robot.

If one of those models is loaded into a scene that contains render engines (e.g., for camera simulation) then there are a log of warnings spammed to the console:

For example:

[console] [warning] warning: Drake currently only supports OBJs that use a single material across the whole mesh; for drake_models/franka_description/meshes/visual/hand.obj, 5 materials were used: 'Part__Feature001_008_005', 'Part__Feature002_005_005', 'Part__Feature005_001_005', 'Part__Feature005_001_005_001', 'Part__Feature_009_005'. The parsed materials will not be used.

It's not OK for Drake models to trigger Drake warnings. We either need to fix the model, or nerf the warning.

For now, our plan is to nerf the warning.

Version

1.19.0

What operating system are you using?

Ubuntu 22.04

What installation option are you using?

compiled from source code using Bazel

Relevant log output

jwnimmer@call-cps:~/jwnimmer-tri/drake$ bazel run //tools:model_visualizer -- package://drake/manipulation/models/franka_description/urdf/hand.urdf --show_rgbd_sensor
INFO: Meshcat listening for connections at http://localhost:7000
WARNING: warning: Drake currently only supports OBJs that use a single material across the whole mesh; for .../drake_models/franka_description/meshes/visual/finger.obj, 2 materials were used: 'Part__Feature001_006', 'Part__Feature_007'. The parsed materials will not be used.
WARNING: warning: Drake currently only supports OBJs that use a single material across the whole mesh; for .../drake_models/franka_description/meshes/visual/finger.obj, 2 materials were used: 'Part__Feature001_006', 'Part__Feature_007'. The parsed materials will not be used.
WARNING: warning: Drake currently only supports OBJs that use a single material across the whole mesh; for .../drake_models/franka_description/meshes/visual/hand.obj, 5 materials were used: 'Part__Feature001_008_005', 'Part__Feature002_005_005', 'Part__Feature005_001_005', 'Part__Feature005_001_005_001', 'Part__Feature_009_005'. The parsed materials will not be used.

RussTedrake commented 1 year ago

I just came to this after hitting a similar wall of warnings in the MIT Quest project (using Drake 1.19). Nerf'ing the warning is a fine fix for now. But I wanted to push back on one of the statements above -- we should be fixing the parser (to support multiple materials), not fixing the few models we curate in Drake to conform to a deficient parser. Everyone else will hit the errors on their models, too.

jwnimmer-tri commented 1 year ago

I'm not sure what specific statement you are pushing back on? Nothing in this ticket should be taken to read that supporting multiple materials would be undesirable, nor do I think I've ever implied that anywhere else.

The franka models were somewhat unique. They used multiple diffuse materials, but with no texturing. Once we have textures involved, things get a lots easier (we can just "bake" the texture with all the materials in one place). In any case, the goal of this ticket was met -- our pre-installed models were spammy; now, they are not.

RobotLocomotion / drake