   Radiosity Normal Mapping
  Is it possible to do radiosity normal mapping without radiosity, using only ordinary lightmaps. I do not understand how I should transform these basis vectors. Should I transform the lightpositions by these vectors. And how can I transform a vector by a vector. I only know how to transform a vector by a matrix?   
  Are you talking about the tangent space matrix?Here is a link about the derivation of that matrix.TBN matrix derivationYou transform the light vector from world space to the local TBN space and there you perform the lighting operations its all explained in the link above   ;  I know how tangent space normal mapping is done. But now I want to add a precomputed lightmap (without radiosity). I 've read the paper from http://www2.ati.com/developer/gdc/D3DTutorial10_Half-Life2_Shading.pdf but I do not understand, what I should do with the three basis vectors.   ;  http://www.gamedev.net/community/forums/topic.asp?topic_id=357006&whichpage=1   ;  Thank you for this link. I've searched quite a lot on gamedev, but I didn't find this link. I don't have to transform the light-position, I only need to replace the normal.   ;  Presuming you are talking about this technique:Indirect Lightinghttp://img218.imageshack.us/img218/5144/nvil3av.jpgGet the documentation athttp://download.nvidia.com/developer/presentations/2005/SIGGRAPH/Truth_About_NVIDIA_Demos_Med.pdfI've made simlar test:http://img218.imageshack.us/img218/2699/room436cf.jpgMore screenshot at my blog:http://www.lifepop.com/myradio.aspx?domain=chenmengjihttp://chenmengji.lifepop.com/   