MeshPart now defaults to "Box" but changes to "Default" when Id is set

It looks like MeshParts were updated to be “Box” collision by default when inserted in studio. This is awesome because it simplifies the builder’s workflow of having to remember to set this.

However - setting the MeshId will change the collisions back to Default. This happens without any indication and is not intuitive. Setting one property should not change another imo!


Well, It’s because natively it’s set to adapt the collisions to the geometry. Before even MeshParts were a thing we used UnionOperations, in which basically acted the same in terms of collisions.

It was like a combo part. Nowadays they aren’t that used because of the lag they create.


“CollisionFidelity” was updated to properly reflect the current state of collisions for the MeshPart/Union.

When you import a MeshPart without an ID set it collides as a box because there is no geometry available. When you set an ID, we still precompute collision geometry and use that as the starting point for every mesh.

Basically the behavior didn’t change. The CollisionFidelity is working as intended because a MeshPart that is imported has no collision geometry and simply collides as a brick. You can think of a MeshPart without ID as “uninitialized”.