Object Space verus Tangent space when doing Normal maps for Environments.

Dallas Robinson

So i was doing some practice with normal maps and looking at portfolios as usual then all of a sudden it hit me. Why is is t that people always seem to use Tangent Space normals when doing normal maps for stuff that will be in the environment? like a rock wall or something? I mean it won't move or animate so why use tangent space normals? I feel like there is something basic that I'm missing or forgetting. Can someone refresh my memory or give me a link to a good tutorial saying why? Thanks!

MoP

It's usually because most game engines primarily support tangent-space normal-maps. Many engines don't actually have shaders that allow object-space maps, hence why people usually go the tangent-space route.

Tangent-space also means you can tile normal-maps or re-use parts of the normal-map more effectively.

Peris

yeah with object space you basically have to texture your entire model uniquely, when do you ever really do that on environment stuff? Some very small props maybe but that's it.

Dallas Robinson

OH! now I remember! Thanks!

And I actually do texture some background element uniquely if the whole model itself is meant to be modular. That way i can squeeze more use out of that item. Then i just hang various other elements around it to mix it up a bit. (example: One big rock wall then hang a bunch of mediem to small rocks around it, add some roots and plants, etc.) I know you can do that other ways but this way works for me most of the time.

Thanks again for refreshing my memory guys :-)