Possibly a stupid question, but can composite nodes be used in the game engine, or can they be easily converted into 2d filters? Im wanting to use it for creating bloom effects etc. Also, does this slow down the game by quite alot?
that would truly be incredible, but, sadly, no. you have to write out glsl filters. as for slowdown, bloom filters slow it a bit, others not so much. here’s a link to a good bunch to test.
awesome thanks! although i still dont understand why you cant do that. it doesnt sound like a complicated thing to put into blender. i wonder if they will think to put that into 2.5 
it’s because they’re coded two different ways. 2d filters are in the OpenGL shading language, and the compositor is in C(or C++ or Python or whatever. i can’t remember). they might be able to code an export, and that would truly be awesome.
… im not even going to try to understand that. someone should make a clever plug-in.