Show me a working example with code, even if it's just cube with whatever tangentspace normalmaps...
I'm not the first to think this up and
ATM - I don't have any web space to upload anything :P
But you can find out more here:
http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
and here:
http://planeta.terra.com.br/educacao/alessandroborges/bump/bump2.html
as well as some Google searching...
The idea is very simple...instead of going in "by hand" and setting verticy colors to reflect thier normals...you reflect those colors from a cubemap (even works with a spherical map)
If you are feeling experimental and have time for a quick do it yourself example then fire up Gile[s] then copy both the normal map and light map images from http://planeta.terra.com.br/educacao/alessandroborges/bump/bump2.html
or use these direct links:
normal map =
lightmap =
go into gile[s] or Blitz3D and create a terrain, then go to it's material..set the surface color to white (255,255,255) with fullbright...then bring up texture number 0...load in the above lightmap (the funky smooth colored one) and set it to spherical before applying it...then bring up the next available texture slot and load in the normal map from above, setting it to Dot3...and presto! You can move the camera around looking at the terrain, it almost seems like you have a bright flashlight hitting it...you can play around with the terrain surface color...changeing it to full on blue (0,0,255)brings out a lot of the detail...but note that both the above linked normal and light maps are rather low quality JPGs, which acounts for the artifacts...the lightmap could use a blurring ot two in image editing software to remove some ogf the "pops")
course that is with a basic spherical map and a non-tangent space normal map...with cubemaps it works much better :)