Web-based URDF visualization tool and library opensourced from NASA JPL

[gavanderhoorn]

@GarrettJohnson

@gavanderhoorn

This is not too well known, but there isn’t really anything in URDF which prevents you from using mesh formats other than .stl , .dae and .mesh .

Yes structure of the format itself doesn’t prevent it – my tool here allows for overriding the the load mesh callback to enable loading any geometry format.

You mean the javascript library loading the meshes? Not in any of the ROS packages, correct?

@GarrettJohnson

It does look like RViz uses ASSIMP to load geometry so this may just be a matter of updating the docs. The URDF spec document makes the geometry format support sound very limited (STL and DAE only):

The recommended format for best texture and color support is Collada .dae files, though .stl files are also supported.

If there are no objections it would be great to update the docs to say that the mesh file extension is flexible but of course compatibility is dependent on the application – most or all reasonable file formats would be supported in ROS via ASSIMP, though. This would enable and encourage users to use more efficient and more generally compatible file formats for their models.

Yes, I’d say updating the documentation would be fine.

Especially in the way you suggest (“compatibility will depend on the application loading the urdf file”).

@GarrettJohnson

We’re using GLTF and GLB and in some cases PLY for our models for a variety of reasons and at least on the surface it looks like we’re creating out-of-spec and ros-incompatible models which seems to not be the case and something I want to avoid.

What would the right way to get the URDF wiki updated be?

Well technically the “only” thing needed to edit the wiki would be to register for an account (and then request write access in ros-infrastructure/roswiki#258).

I write “technically”, as there is another aspect here, which is how compatible this is with “older versions of URDF”.

I don’t believe that’s a problem here though: Assimp has been used “since time immemorial” in ROS to load meshes, so I believe using formats other than the three listed now is supported on all supported ROS releases.

@GarrettJohnson

@clalancette

We’ve been discussing this in various places, most recently over at https://github.com/ros/urdf/issues/34 . Feel free to join in the discussion there.

Great, thank you! I’ll write something later this week.

Related (since you mention gTLF and GLB): ros-industrial-consortium/tesseract#184.

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Edit: also related (and very nice): it seems Ubuntu Focal comes with version 5.0.1 which supports .zae, which is compressed Collada (assimp/assimp#2545). That potentially saves up to 90% on mesh (and typically also ROS package) size.

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Edit 2: hah, just noticed that we’ve discussed (almost) all of this 2 years ago: Support the PLY geometry format in URDF? - #4 by gavanderhoorn.