[Radiance-general] glow&spotlight material

[WOOK JEA OH]

Hi, This is woogie.

I am trying to study material characteristic in Radiance by using Desktop
Radiance in the DOS mode.

I have some problems with glow and spotlight material.

I made a simple scene with only two surfaces facing each other.
One of surfaces is light source and the other is plastic.
the plastic surface (1x1m) is 5m apart from the light source material(1x1m)

And I plugged in different light source material to see if there is differernt.

Light and illum material result in the same illuminance value as that by hand
calcuation.

When it comes to glow material, it seems to me odd.
The first, It is said that the fourth argument, maxrad in the glow material can
be negative, zero, and positive. 

When the fourth argument is zero, illuminance value on the floor(1x1m) which is
5m apart from the glow material(1x1) is not uniform.

Light amd illum material result in the uniform illuminance value on the floor
with the same geometry material setting.

It seems to me that rendering parameter might not correct because the center of
the floor is darker than the edge of the floor or it comes from Desktop
Radiance or it is because I did not understand the fourth argument in the glow
material.

If anyone knows of my problem, please let me know.
I am linking a file below

http://www.personal.psu.edu/users/w/x/wxo110/radiance.htm

I appreciate any comment about it.
Thanks!

>From woogie.