Eeeh, we're getting a bit offtopic here.
And you don't break apart ROMs.
GameCube discs do not follow the ISO standard, although a somewhat similar one called "GCM" that's some crazy acronym.
So there's no such thing as a GameCube ROM.
There's a program called BMDView that views the BMD models inside some GameCube games. The games thats models follow the BMD model standard are Wind Waker, Super Mario Sunshine, Mario Kart Double Dash and a [truck]load of others, too. What I basically did was snag a ZIP containing a bunch of BMD conversions to 3DS, the 3D Studio file format which is very common.
BMDs can be viewed and exported to 3DS with BMDView, yes, but you need to extract the GCM data files out from it. This requires another tool that I won't mention because I'm yet unaware of its legality.
