I've used the quick hull collision shape generator (or whatever it is called) several times and it seems to work pretty nicely. You just need to select the MeshInstance node and then there should be an option called Mesh. If you click it, you will be presented with several options that create collision shapes (and more) from the mesh selected.
In Godot 3.2 there will also be a new way to make a Convex collision mesh in the Godot editor.
Hopefully this helps :smile:
