They really are cinematic animations, rather then Cinematic Physics. If they were realtime then that would be pretty damn sweet, but sadly they aren’t.
When EP2 came out, we immedaitly jumped on it, and tried to do it, only to find out that it’s complicated. Not in the way that we didn’t think it would be, but natrually there is a few, or well many steps that we’ll have to take in order to achieve what Valve’s program can do in ten seconds.
1. First off the animations need to be precise, because if the enviroment changes, then you may see chunks of debree flying through a solid wall. This is what makes the animation a bit difficult to produce, simply because you can’t change it that much. The enviroment first needs to be created within Hammer, and of course the finished enviroment, which of course takes it’s own time to complete. Then saved into a map file called a BSP.
2. We then use Crafty (Because its freakin Awesome) to open the BSP and export the basic Brushwork into an OBJ. File. Which is accepted by most moddeling programs.
3. Then we open that OBJ. file, and create the animation, (using the objects on the obj. file which are just presented as blocks) as means for physics collision.
4. Of course we also need to make the animation, and turn that animation into a model as well. Which doing the animating takes it’s time to tweak just right, as well dependant on how complex it may need to be.
5. Then run it in game, and hope to God it doesn’t look like crap.
Its a Rinse, Repeat sort of process for us.