I've just about started with a project I've had in mind for ages. I don't quite know how to start such big projects (bigger than Pong, anyway), so I thought I would get started by making a basic organization.
Now, in games like Freelancer and X feature large, open spaces. I ma aware that these have to be organised, to ensure collision testing don't happen continuously anywhere but only where the player can see it.
I thought first about a general scene graph, I am familiar with those, but it would just have almost all objects directly in the root node. The next idea was a Quad/Octree, but the objects are not quite static, and I don't know if it would make sense if you have to change the tree's organisation every second frame.
So, how is this done in real games? I'm using C# with XNA, if that matters, and would like to run the game on the XBox as well.