[Radiance-general] color of the light source

[Bei Xiao]

Hi, Greg
 Thank you. I am generating hyperspectral images using Radiance and also
PsychotoolBox. For right now, I rendered 24 chips of the macbeth
checker board to test the code of generating right color of hyperspectral
images. But the color of the objects come out weird because the light has a yellowish
color. So everything looks yellowish.

  I follwed the thread of the specular reflectance. But i am not so clear
what does the -st (specular thresold mean). Currently, I set the -st as
0.1. But I found whatever falue I use for specular reflectance, the effect
of the glossiness is not big.


Thanks,

Bei

 On Fri, 14 May 2004, Greg Ward wrote:

>_Hi Bei,
>_
>_Colored sources are a complex issue due to white balance.  Instead of
>_giving you a long-winded and incomplete reply, I'll refer you to the
>_paper I coauthored on the subject:
>_
>_	http://www.anyhere.com/gward/papers/egwr02/
>_
>_Have you been following the related thread on spectral reflectance?
>_
>_-Greg
>_
>_> From: Bei Xiao <beixiao at mail.med.upenn.edu>
>_> Date: May 14, 2004 1:32:39 PM PDT
>_>
>_> HI,
>_>  Thank you all very much for the previous replies.
>_>  I have another very rudimentary questions about the rendering. I use
>_> a point light source in my rendering of the following parameters:
>_> void light bulb_light
>_> 0
>_> 0
>_> 3 5000 5000 5000
>_> Am i suppose to render the scene with white color?
>_> But this light source illuminate the room with yellowish color. How
>_> can I
>_> get the white illumination? Is there any parameter that I need to set
>_> to
>_> get the correct color of thelight?
>_>
>_> Thanks a lot.
>_>
>_> Bei
>_