Is the main reason to have these two seperated so when you're doing frustrum culls, and it happens to exclude an object outside of the screen, but the computing for the object needs to be there, just not the picture, you can simply do that?
I'm thinkin if you have a troll camp just out of your view distance and theyre baking a prisoner alive you want that logical action going on, you just don't want to draw it.. so you simply delete the renderable representation of the object and then keep performing calculations for their logic..
Right?
Or am I missing the idea of the thing completely?