Collision between only some elements of one model
I want to know please how can I turn on collision between only some elements of one model. For exemple: I want to detect the collision between link 6 and link 1 of my robot but not between link 1 and link 2. So that, link 2 can go through link 1. I have tried collision_bitmask but it did not work for me. I need some help please. PS: I am working with an urdf file. Thank you by advance