How to store content on disk? What format should we use? There are a verity of 3d tools out there, from milkshape to blender to gmax on the free end with lightwave and maya on the high end. There is also the possibility of different clients programmed with different systems. They too have their own formats. In order to reach the biggest number of content creators we are going to need a file format that is as platform and engine neutral as possible. COLLADA (http://en.wikipedia.org/wiki/Collada) will provide us this. It is an XML schema for 3d mesh, physics, and a host of other bits of information that might interest us.
don't ever touch COLLADA, this format is so open that every 3D Tools screwed it up with his own tags, nothing is really defined as on how to handle things and no library is able to read it
Take a look at fbx instead, even if it not the a silver bullet it is by far the most stable format as of today
And definitly you should make your own format for runtime, and provide tools to Custom content creators to convert from a standard format to your proprietary one
Any standard format will contain many informations that you won't need at runtime and sometimes will miss some, you'll have to compute them. It is far better for loading time and memory to have the computation offline ( ie not in the game itself )
My 0.02€
PS : you better take a look at assimp (http://assimp.sourceforge.net/) on sourceforge, I'm very pleased with it
Thanks for your input Wou :D
Joe