I am modifying the mesh at runtime.
After the modifications are done, I need to update the mesh collider.
The operation of assigning the mesh to the collider causes a freeze like in this example:
so you can not orbit for a while.
Is there a way to get rid of that by moving the process to the background thread?
I don’t think you can update your collider on another thread, it has to take place in main. You can move your calculation to threads, but not the assignment. A similar question was asked here (not about collider, though).
Anyway, mesh colliders require some serious pre-processing, and are not that viable for update at runtime, maybe you should rethink your flow so you don’t have to do this.