How Expensive is Parallax Mapping?

cycloverid

Just how expensive is it?

When implementing parallax mapping on assets, when would one draw the line between poly details, and putting it in the heightmap? For things like bricks this seems obvious enough, but I'm just curious as to how it compares to polygon details.

It seems like the answer most would give is: if in doubt omit it. But, it's a very interesting new technology.

Eric Chadwick

Not very expensive on current-gen hardware, but it depends on the method too. Some info here.
http://wiki.polycount.net/Parallax_Map

Biggest drawback for us is that other meshes sitting on a parallax-mapped surface will sometimes look like they're floating, because the parallax distortion goes "down" into the surface.

DarthNater

I'd have to argue that the extra increase in polies would be easier on the system than parallax mapping is. It takes less time and memory to pass vertices to the GPU than it does to create the effect.

Am I saying don't use it? No, obviously it would be more efficient to parallax map those stones in the Oblivion picture in Eric's link than it would be to model them all. I'm just saying use it sparingly.