Well you won't create an engine (unless you are a crazy 3d physics programmer of some sort). Chances are you will use an existing 3d engine like the CryEngine, or one from any number of games that supply their game engine.

If you are giong to make a game, I'd suggest spending time deciding what engine you will use first. Because much of how you make your models will depend on how your game engine can accept them. Some engines are VERY picky about how their models can be made. Other engines are a little nicer about it.

what format would you need?

@chris fullmer said:

Probably, what file type does anim8or accept?

.3ds, .lwo and .obj if I remember correctly, along with it's own .an8(?) format. Probably the easiest way is to export .obj from SU and import into anim8or...

Cheers.

@dominicm143 said:

i've saved my old model as a component, and now it won't ...
~dominic muscatella

Exactly how?

I don't know what's in your model, but try this technique which I'll explain as if you've modeled a house.

Explode. Delete everything but the top story and roof. Save as 'attic'.

Reload. Delete everything above ground. Save as 'basement'.

Continue until you have a collection of tractable pieces. You can now delete the original. (Well, save to another name: my_old_model_that_I_may_not_need.skp.)

To rebuild, File/New, then import the parts one at a time, clicking the origin. They should assemble correctly if you import each to the origin.

That will give you a collection of small, easy-to-use models. One other technique. If you move everything in the 'attic' model into a layer named 'attic', when you import you will have a single component named 'attic' in a layer named 'attic'. Very handy for SketchUp animations.