[Bf-docboard] Correction for Lighting chapter

[instinctive new media]

Hi,

after reading the chapter on lighting, I'm not quite sure if the description
of the "Bias" value is correct. 

I might be wrong, but in my opinion it just shifts the shadows back and
forth from the lamp to account for inaccuracies. It does _not_ improve
shadow quality, it's merely a corrective measure.

Tell me if I'm wrong.

| alexander ewering           instinctive new media
| ae@instinctive.de       http://www.instinctive.de 
|
| fon: +49-2393-220558         fax: +49-2393-220559