making holes in a mesh

hi,
I was wondering how to make holes in a mesh. For instance, let’s say the player has a gun that can make a hole in the wall (something like Portal, but without creating a portal, just a hole). I was thinking about using shaders to make that part of the mesh transparent, but I also need to disable collision detection so the player can go through.

any ideas?

Seems like a lot of work. The two obvious ways to do it would be to either use alpha to make a hole in your textures or dynamically tesselate your mesh to cut a hole in it.
With the texture method you’ll have to create a shader that will somehow render the wall thickness depending on the angle you are facing it otherwise your walls will look paper thin. Though i’ve seen shaders do this kind of things for alpha test textures, I’ve never seen it done properly for a simulated thickness large enough to emulate a wall. You would then have to create a dynamic atlas for all your breakable walls very much like a lightmap to create and store all the holes.
Dynamic tesselation is pretty straightforward and I’m sure a lot about it has been written. Given the number of AAA games using it to create destroyable levels, I’m pretty sure it must be a nightmare to implement. Think at all the calculations necessary to make a whole building fall because it is not supported by enough walls !
In most games i know with destroyable levels, the crumbling is pretty much always fully scripted… Good luck with your project !

thanks
However, as you said, it’s probably a nightmare to implement! So I wanna find a way to disable collision detection for the part of the mesh with the hole without modifying the mesh