Mesh Combining

The mesh combination menu allows you to combine multiple rock meshes into 1 mesh. Simply add a parent object into the slot and all the children of that parent object will be combined into 1 mesh. You can also pick a name for the new combined rock mesh and you have also several options to choose the type of collider you want, whether or not multiple materials should be preserved, if the new rock should have a rigidbody and if the old meshes should be removed.

You can also see how many meshes/vertices you will be combining.