[Radiance-general] Color Bleeding

[Marcus Jacobs]

Dear Group

I have come across an issue with the color bleeding of image maps that I use 
with my Radiance renderings. I have the dual objective of achieving a 
physically accurate and asthetically pleasing rendering. It is my 
understanding that to obtain physically accurate attributes for a material 
associated with an image map, one should normpat'd the image and then set 
the appropriate rgb reflection for its associated material. The problem I 
have come into is that the color bleedng seems excessive. Here are some 
examples:

For the wood floor image map in this rendering, the image map was not 
normpat'd and a rgb reflection for the floor (plastic) was set at .4 .4 .4. 
The floor image map brightness is a bit darker than what I would expect:

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=d98b.jpg&.src=ph

For this rendering, the wood floor image image was normpat'd. The red green 
blue option in colorpict was set to red green blue and a rgb reflection for 
the floor (plastic) was set at .4 .4 .4. Notice the level of color bleeding 
in the rendering. Also, the brightness and saturation of the image map is 
much higher than the pre-normpat'd image map:

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=e6b4.jpg&.src=ph

In this rendering, the wood floor image map was not normpat'd and a rgb 
reflection for the floor (plastic) was set at 1 1 1. I know not how 
physically accurate the floor material is reacting but the brightness of the 
floor material is what I think I would expect:

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=adb6.jpg&.src=ph

In this rendering, the wood floor image map was normpat'd, the red green 
blue option in colorpict was set to clip clip clip and a rgb reflection for 
the floor (plastic) was set at .4 .4 .4:

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=3242.jpg&.src=ph

In this rendering, the wood floor image map was normpat'd, the red green 
blue option in colorpict was set to grey grey grey and a rgb reflection for 
the floor (plastic) was set at .4 .4 .4:

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=36c5.jpg&.src=ph

In this rendering, the wood floor image map was normpat'd, the red green 
blue option in colorpict was set to noop noop noop (I think this was 
recommended in RWR) and a rgb reflection for the floor (plastic) was set at 
.4 .4 .4. This rendering and the floor is very saturated.

http://pg.photos.yahoo.com/ph/marcdevon/detail?.dir=/b3e9&.dnm=d1fc.jpg&.src=ph

I guess this is the rundown. Any suggestions?

Thanks

Marcus