Physics Collider Baking inconsistency

[tired stump]

What is the recommended approach to do something like a conveyor belt placement at runtime ?

A conveyor belt need to have an input & output sockets.
And the conveyor belt is basically a spline with a few system modifying the mesh at runtime.

How do you do a Physics Collider for each of the parts ? ( Belt, and one for each sockets ) Starting from a prefab with subprefab ( one for each component )
How to be sure that the sockets are not updating their collisions filters BEFORE the belt is placed ?

Again what would be the correct approach ?

My idea would be : ( cf screenshot ) purple : visual, green : a physic collider is present

Same question : how do you ensure a mesh collider is baked with an empty mesh ? ( I need to put a cube mesh for it to be present after conversion ) So I can update it at runtime ( if no mesh present it's currently not adding the physics Collider component )

Same thing about parenting loss at baking. in my screenshot If I don't add the Parent component at baking in a authoringMonobehaviour, the two socket lose parenting :/

[hoary dust]

Let me unpack this a little.

For starters, we currently don't support baking "empty" meshes. We simply don't create the rigid body if there is no collider present.

You can though manually create rigid bodies in code if that helps.

You could use a compound collider to represent your conveyer belt, e.g., using multiple boxes that you place and shape in accordance with your spline.

Or you can create a MeshCollider using the MeshCollider.Create() function and handing it input vertices and triangle indices.

If you want to do procedural conveyor belt creation based on a spline, I think procedurally creating the physics of the conveyor belt would be the best way to go here.

You could have a look at the ragdoll demo in the PhysicsSamples. The ragdolls including their graphics are created in code as entities. Maybe that could give you some code to work with as a starting point.