How do you make your buildings breakable?
I do not know how the professionals do it. I am relatively new myself to the 3D stuff. But here is how I do it.
I design each piece of my model separately ( Wheels, Fenders and etc. ) then I assemble them into 1 model. I do not weld any of the meshes together. I attach a node to each section, then I animate the model simulate explosions or damage. By not welding the meshes together, I am able to pull them apart from each other in the animation sequence.
I do not know how the professionals do it. I am relatively new myself to the 3D stuff. But here is how I do it.
I design each piece of my model separately ( Wheels, Fenders and etc. ) then I assemble them into 1 model. I do not weld any of the meshes together. I attach a node to each section, then I animate the model simulate explosions or damage. By not welding the meshes together, I am able to pull them apart from each other in the animation sequence.
I think he's asking about things that can't be defined as a combination of other things, like a wall.
I also don't know how it's done in big games, but I guess you can have a model for the full object and a model of the object broke into pieces, and change the model when it must break appart. Or instead of having one big wall model, have a wall composed buy a number of small walls that each one can break appart, so you can break only a portion of it.
Another option could be to make another model in real time through code to consider where was the wall hit and make it more realistic. The same for a tree, if you know where the bullet went you might be able to create 2 models, one containg the vertex below the bullet hole and one containing the rest. Anyway, this approach doesn't sound easy, so maybe it's not the first you want to try.
http://www.videocopilot.net/blog/author/andrew-kramer/
Some possible useful CryEngine docs
http://docs.cryengine.com/display/SDKDOC3/Cloth+Merged+Mesh+Deform
