Creating Normal Maps

[Aegrus]

I've been working on a complete HD texture overhaul for Dragon Age; Origins. I've been replacing vanilla textures with completely remade, 2048 textures with simulated baked lighting on them. I've also been re-making every normal map at 2048.

 

I know how to make normal maps, and I've been using grain-merging in GIMP 2.6 to increase their depth. The issue is, I'm not sure if grain-merging is an acceptable way to improve a normal map for a game. Are grain-merged normals optimized enough to run well?

Edited January 2, 2013 by Aegrus

[BarefootWarrior]

While I am familiar with 'grain merge', I'm not sure how one would use it in a normals map. If the grain merge is already incorporated in your diffuse texture, there should be no need to add that feature again in the normals map. What I do to increase 'depth' in a normals map is to duplicate the layer, increase 'contrast' (in the duplicate layer) and then 'flatten' the layers, then go on to create (save) the final normals map. I do this in both Photoshop and GIMP.

 

And, increase or decrease brightness in the alpha (if one is used) to add shine or to make dull. I'm sure someone else may have something to add to this, and possibly more familiar with the technique regarding your question. :unsure: