Hi, 1. I'm trying to roll a ball down a plane inclined at 10 degrees. In the simulation, the plane and the ball are imported meshes. I have put the mass of the ball as 84000kg. In the simulation, the ball rolls down the plane at a slow pace compared with the real-world. I have increased the timestep to a maximu of 0.01 but it doesn't seem to be making a difference. I have also varied o_solimp and o_solref and observed that o_solimp = "0.9 9.95 0.01" produced the best result but that is still slow. -> Could you please help me understand why ball moves slowly and what I can do to change it? 2. On a related note, I've observed that when the ball slides down the inclined plane, the number of contacts is '0' most of the time. I have put collision = 'dynamic' in options element. -> Why is the number of contacts zero even though the ball is in contact with the plane? Thanks for your help.
This is a very large mass... are you sure a real ball with that mass would roll faster? Is there a reason you are importing the ball as a mesh instead of using a sphere geom? The mesh may not be in contact with the plane all the time, causing 0 contacts; this could happen if there is a small flight phase in-between contacts along the edges of the mesh. If you upload your model I can take a look.
Thank you for your reply. Yes, the mass was too high. I was actually scaling the mass by 100x as I had scaled the dimensions by 100x. But reducing the mass and the dimensions of the sphere proportionately did increase the speed comparable to with the real-world case. I also used the sphere geom instead and it did solve the problem of 0 contacts. Thanks again for your help!