Update collision by region

[SpicyFlanx]

Description

I'm working on a project with terrain modification (explosions that leave craters in the terrain). The dynamic mode isn't appropriate for what I'm doing, but rebuilding the whole map for each modification is slow and wasteful. Could the update function allow for rebuilding only a single region?

[TokisanGames]

I'd accept a PR for that. Shouldn't be difficult.

[rpgshooter]

Simple enough building blocks are there just need specific index updates, might do a draft with a possible implementation