francogassibe

As explained by @jr-b-reiterer . Inverse kinematics may have multiple solutions (8 in your UR5 case). Witch solution is returned on numerical methods (like ikineLM ) depends on some seed...

i have done some research and based on what this https://github.com/kmammou/v-hacd git says in its presentation (slide 16) the meshes have to be watertight (whatever that means) with no holes...