Onshape Importer loads assembly incorrectly

Omniverse Isaac Sim
1

5.1.0

Operating System

Windows 11

GPU Information

  • Model: RTX4060
  • Driver Version: 591.74

Onshape importer incorrectly imports the robot

Detailed Description

When importing a simple robot, with only 2 wheels, they appear disconnecetd and frame is somehow inisde of a tree of one of the wheels. The wheels are mated through revolute joint to their brackets in Onshape. Brackets are mated to the frame via fixed joint.

Steps to Reproduce

  1. Import from Onshape

  2. press play

This is how it looks in Onshape

image
image1586×909 171 KB

And this is how it looks in Isaac Sim

image
image1597×723 152 KB

image
image1432×901 160 KB

First - Why is Frame inside a Wheel_Assy_RH?

Second - why wheel assys are not connected via Fixed joint?

3

Hi @pkoprov, thank you for posting your question. This seems like an unexpected behavior. We are looking into it and will get back to you.

4

Hello! Would be good to know what is on the frame subassembly. The recommended course of action is ensuring the entire fixed subassembly be placed on a group mate to ensure the importer will interpret it as a rigid structure. Another thing to check is the order the mate is made. In Onshape it does not matter much but sometimes it may cause some confusion in the converter to decide what component is should be combined as a single rigid body.

The Onshape importer will try to make some assumptions but sometimes the topology may not be correctly interpreted.