Why chalk blue?

Blitz3D Forums/Blitz3D Programming/Why chalk blue?

Whats My Face (Posted 2008) [#1]

I was wondering how I would go about drawing a env. bump map. Why is it that chalk blue? And what determines what appears bumped-in or bumped-out? I know there is probably a thread on this already but I can't seem to find anything anywhere.

Stevie G (Posted 2008) [#2]

Never used them myself but I'm pretty sure the RGB components define a vector representing the normals for lighting ... Nx# = ( Red - 127 ) / 127.0 Ny# = ( Green - 127 ) / 127.0 Nz# = ( Blue - 127 ) / 127.0 There are loads of discussions and code re this.

Ross C (Posted 2008) [#3]

Yeah, i have a height map to normalmap convertor in my sig below. I may need tweaking though, as someone complained of an error. Works ok for me :D And Stevie is correct in how it works. Blitz really only works well with world space normalmap, but you can use tangent space normal maps with a cubemap, to produce good results. Look for a thread also in the showcase part, started by Devils Child. It's about his engine.

Whats My Face (Posted 2008) [#4]

Thanks for the explanation Stevie G and thanks for the converter Ross C.