The problem of importing URDF with GPU pipeline

Autonomous Machines Robotics - Isaac Isaac Gym
1

Hi, I would like to do pick-and-place experiments with various objects with robot-arms at the Isaac Gym.
I am still using Isaac Gym Preview 2.

The URDF loading behavior is different between without the GPU pipeline (1st image) and with it (2nd image). Of course, they read the same URDF file.
Perhaps the value set as the inertial origin is also read as the collision origin. However, the collision meshes are rendered by its original origin (3rd image).

The following is my URDF file. It is a 0.12 m high rectangular object. Its bottom is a square of 0.02 m per side. And the origin is at the bottom, so the center of gravity set at z=0.06.
I know I can easily create boxes with “gym.create_box”, but I want to create a variety of objects in Blender, so I use URDF.

<?xml version="1.0"?>
<robot name="cuboid">
  <link name="cuboid">
    <visual>
      <origin xyz="0 0 0" />
      <geometry>
        <mesh filename="../meshes/visual/cuboid.dae" />
      </geometry>
    </visual>
    <collision>
      <origin xyz="0 0 0" />
      <geometry>
        <mesh filename="../meshes/collision/cuboid.obj" />
      </geometry>
    </collision>
    <inertial>
      <mass value="1.0" />
      <origin xyz="0 0 0.06" rpy="0 0 0"/>
      <inertia ixx="0.002" ixy="0.0" ixz="0.0" iyy="0.002" iyz="0.0" izz="0.001" />
    </inertial>
  </link>
</robot>

Are the developers aware of this behavior?
If this was a bug and fixed in Preview 3, please tell me.

Thank you for your answer.

sim_params.use_gpu_pipeline = False

IsaacGym_without_gpu_pipeline
IsaacGym_without_gpu_pipeline1177×586 72.4 KB

sim_params.use_gpu_pipeline = True

IsaacGym_with_gpu_pipeline
IsaacGym_with_gpu_pipeline1157×557 72.7 KB

IsaacGym_with_gpu_pipeline_render_collision_meshes
IsaacGym_with_gpu_pipeline_render_collision_meshes1154×611 51.2 KB

2

HI
The documentation does not mention objects created with URDF. So what you want to do isn’t even possible in Preview 3. I request NVIDIA to work with Blender.

3

What did you mean?
Preview 3 can also import URDF as a matter of course, and documentation mentions about it in docs/programming/assets.
Now, I hope to discuss whether the gpu pipeline’s behavier was fixed or not. Blender is not the purpose.

4

So why not use Preview 3?

Regarding blender, it is a request for nvidia.

2021年11月4日(木) 18:11 Takushi Kodani via NVIDIA Developer Forums <nvidia@discoursemail.com>:

5

I created a new environment for Preview 3, and the above issue was resolved.

Thank you for your reply and excellent developers of Isaac Gym.