Hi there,

I am just trying to set up a simple car rig in bullet and ended up with a bunge of questions regarding constraints in general. Please find my questions below, I also attached a file of the “working” rig.

- Is it somehow possible to limit the spring to one axis? When you press play and watch the simulation in my file the wheels totally get displaced from their attached position after the car gets hit from the cube. Would be nice if the spring would only be springy in the y direction and work more like a glue on all the other axis. I was trying to use condof & condir to free up all the other axis and tried to add a glue for all the resulting unconstrained axis but
condof & condir don't really work as expected as they are just changing the anchor gizmo (result felt the same) and combining various constraints for differnt axis as far as i know never worked in houdini. So in the end what is needed here is a glue for x,z position and xyz rotation and y position spring. How can I set up something like this?
= Is there a way to make the conetwist springy maybe?
- My next problem is the attachment of the wheels. Right now I am using a slide constraint. The problem with this is that the rotation of the wheels feedback to the spring constraint which makes the chassis jump like a lowrider. This is getting more obvious when you get rid of the box collider and just add some initial velocity. I can reduce the effect by reducing the density on the wheel/ wheelmount, but this would mess up the spring which is wonky enough in this case already. So my two questions in this regard are how can I attach a rotating object to the end of my spring and how do you guys approach density balancing in your scenes.

If you have any answers to my questions all help is greatly appreciated.

Cheers