Re: pfLightSource::ProjTex question

New Message Reply Date view Thread view Subject view Author view

From: Devrim Erdem (devrim++at++vires.com)
Date: 11/14/2001 13:36:56


>
>
>The multipass algorithm in pfLightSource builds up a greyscale lightmap in
>the framebuffer. When building this lightmap, the contribution of each
>lightsource is additively combined with the rest of the scene. After all
>the lighting, we multiply the lightmap by the scene rendered normally
>(colors, textures, but no lights). So, anything black in your scene will
>multiply the lightmap by 0 and it does not get illuminated. This is
>correct behavior for diffuse lighting - a black object will not reflect
>any light. There isn't any way to light black objects with projective
>pfLightSources.
>
>For headlights, which do not move with respect to the eye, you could just
>create a texture that contains your desired headlight shape and in the
>draw callback, add it to the scene. The faster approach is to blend a
>texture containing the light lobe shape on top of the scene after
>rendering. The nicer approach is to project a texture onto the scene. In
>either case, you only need two passes. This approach will light black
>objects, but "adding" light to a scene does not look very realistic unless
>the light does not contribute much.
>
I have also implemented the post-draw-method. However, as you say it is
not realistic since black pixels are now gray and the underlying texture
can not be seen. ( My geometry is multitextured with base texture +
shadow texture ).

It looks like the technology is not yet there to light objects which are
statically shadowed using multitexture and I will falk back to the
traditional method with slightly modified textures.

Thanks Marcin.


New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Wed Nov 14 2001 - 14:02:15 PST

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.