Jrock, he doesn't need to edit the source to make the "grahpics" look better.
He needs to make "better" models and textures.
Fact is, the models are made of a certain quality, so are the textures. It's not like you can make a 512x512 texture 1024x1024 and make it look good, it's like zooming in on a tiny picture a hundred times and expecting it to retain the look it starts with--it just doesn't.
That said, there are things you can add thorugh source alterations. You could, for example, add partiles, or Newton physics, or any physics able to be integrated into DBP. That won't make existing things look better though.
Fact is, the DBP itself is the threshold. DBP can't run high poly models efficiently, so neither can DBP. It's as simple as that.
Evil has a new name. Demo out now!