Why do you want to use B3d's coordinate system, if you're making an engine for BlitzMax, is it so you can convert the sources across? BlitzMax uses OpenGl, so I'd have thought the natural way to do coordinate systems would be the OpenGL way. If that requires converting models, either pre load or at load time, then do it.
Also, if you're worried, I'd abstract out a coordinate system into a Type - DO NOT hardcode it, and allow the engine to be setup with a coordinate system. That way, you write your Blitz3d one that works all happily, and then if you change your mind, you can just plug a new one into the engine and away you go. Also this means users of your engine, if there are any, could decide how they doit.
Aaron
Also, if you're worried, I'd abstract out a coordinate system into a Type - DO NOT hardcode it, and allow the engine to be setup with a coordinate system. That way, you write your Blitz3d one that works all happily, and then if you change your mind, you can just plug a new one into the engine and away you go. Also this means users of your engine, if there are any, could decide how they doit.
Aaron