Very big robot apear then vanish in pybullet

[FrGe2016]

Hi

I have tried a very big robot basically a gantry crane with a few arms ( 30m X 10 m X 10m ) moving along a 60m rail.
It apears in bullet for about 1 second then vanishes.

If i use ros2
The robot is displayed in rviz and every joint move perfectly
But i also have simulation problems with gazebo. ( the robot definition is available but no display )

I have found a partial solution
Increasing the ground_plane surface in the file .../.local/lib/python3.10/site-packages/onshape_to_robot/bullet/plane.obj

This way the robot is on the ground plane as long at no joints moves.
From this moment, the robot flip over and fall below the ground plane ?

Since the robot moves on rails is the any way to lock the rails on the ground ?

[Gregwar]

Hello,

Do you pass -f to onshape-to-robot-bullet ?
This makes the robot "fixed" (else, it is considered as floating base, like a mobile robot)

https://onshape-to-robot.readthedocs.io/en/latest/commands.html#onshape-to-robot-bullet-running-bullet-simulation-to-test-your-robot-urdf