this is a weird thing but i'm becoming mad...i think that many of you have already seen the demo of my engine with dot3 bump mapping etc... but i still have a problem with per pixel lighting. i've a list of faces and vertexes. every face has a normal. So i know faces and vertexes coords and their normals. Now i want to compute tangents and binomials for every face and for every vertex... how can i do?

In this thread Eric Lengyel gave code to just about the best way to calculate tangnts (and binormals/bitangents?).

But next time please use 5 minutes to search for things like this, as the same question is asked about once a week :)

The most common way of computing the TBN triplet is using the UV space that already settles your texture coordinate, because the texture coordinates somehow "follow" the natural curvature of the mesh.

The topic has been discussed many times here and there. Search the forums or google it.

[edit: nice one Mirko I haven't seen you already posted]

thank you guys :D
@vincoof: nice advice,i'll search on google for UV mapping
@DarkWIng: sorry, but sometimes i'm simply too lazy for searching alone :P