Use Newton loading URDF

[Tadinu]

Hi @kavanwyk,

Thank you very much for this amazing repo for the community, the first afaik on using Warp for batched Fabrics!
Earlier, we used to only have https://github.com/tud-amr/fabrics, a great one by @maxspahn.

This PR mostly is only for reference regarding:

• Using the latest warp, which deprecated warp.sim, in favor of Newton.
• Using Newton for URDF loading
• Visualizing palm targets

Notes:

• Regarding RobotVisualizer, which currently uses IsaacSim, in line with this PR, the results could be also probably visualized by the more light-weight in Newton.
• Unfortunately, the changes are full of formattings done automatically by IDE, so it may be really hard for reviewing (my great apology🙏).
• Mostly, the main changes are:
  • pyproject.toml, setup.py, deps.txt: remove urdfpy
  • README.md: update installation steps by replacing one for urdfpy with newton
  • fabric.py:
    • add FabricJointMeta data class, hosting joint info: name, type, upper/lower limit
    • BaseFabric: remove urdfpy_robot, joint_names -> joints_meta, _num_joints -> property num_joints: len(self.joints_meta)
    • load_robot(): use newton.ModelBuilder instead of wp.sim.ModelBuilder, loading joints meta directly from the former.
      -> Keep newton.ModelBuilder as class member for more conveniently later browsing, as the compiled model possibly resides in GPU.

• import_urdf.py - parse_urdf_annotated():
  • use newton.parse_urdf(), removing supporting utils like KinematicTree, expand_link() for the old loading function.
  • then save the parsed model meta into UrdfInfo (Most important changes)
• kinematics.py:
  • Joint type enums from wp.sim -> newton.JointType
  • KinematicsBase init: wp.sim.ModelBuilder -> newton.ModelBuilder
• world_mesh_model.py - create_object_model(): wp.sim.ModelBuilder -> newton.ModelBuilder

[maxspahn]

@Tadinu Thanks for mentioning me ❤️