Section 7.4. Destruction Proxies
Destruction Proxies are similar to Proximity Proxies, but instead of swapping close to the player – they swap close to impulses and destruction events – both single and multiplayer is supported.
They’re swapped into Geometry Collections which can then be destroyed. You can also set either a Destroyed Mesh, or a Destroyed Prefab which are swapped in at the end of the destruction, and used from then on as the main ISM or Prefab in the distance too. If the destruction is happening further than a certain distance from the camera – the geometry collection isn’t swapped in, and if something is destroyed, the Destroyed Mesh/Prefab is directly swapped in – if you add a dust cloud at destruction time, it masks it nicely and keeps things ticking along optimally.
Specify an index of -1 to assign all instances of the mesh to the Destruction Proxy.