> Alain <aze### [at] qwertyorg> wrote:
>> In both cases, when the end is inside the plane, you have one less
>> surface to traverse. It's normal that the tint is not the same.
>>
>> In the non-radiosity case, the light is to one side, so that the
>> illumination is not the same. What you see is as expected.
>>
>> In the radiosity case, you use "recursion_limit 1" whitch is not enough.
>> If you use recursion_limit 2, the black areas disapears. You realy need
>> recursion_limit 3 to have good result. You need to change your "sky
>> with: pigment {color White }finish{ambient 1 diffuse 0}
>> Otherwise, it gets REALY to bright as the plane illuminate the sky.
>>
>> If you expect the colour to depend on the thickness of the object, you
>> need an interior where you define a fade_color, fade_distance and
>> fade_power. Without that, only the surfaces affect the resulting coloration.
>>
>> Unrelated: assumed_gamma in the global_settings is been phased out and
>> will not be supported in future versions. It's beter to NOT use it and
>> only rely on the effective illumination level. Instead, you should rely
>> on the gamma settings from the main ini file, and NOT change it for a
>> given scene.
>>
>>
>>
>> Alain
> 
> Thank you, I appreciate the helpful information. I re-rendered the test scene
> using recursion_limit 2 and 3. The dark areas on the plane AROUND the cylinders
> did indeed disappear, but the dark area causing the "bottoms" of the cylinders
> to appear black remained. I still think there is a problem with the way
> radiosity and transmit (also filter) interact. I'm reasonably sure that if one
> had a real cylinder made of a clear material and placed it near a white object,
> there would not be any dark ring like we see in these images.
> 
> I tried using interior. Without radiosity a mostly-transparent object looked
> great, but adding the radiosity caused the dark ring to appear again. I'm not as
> experienced at using interior so I'm probably doing something wrong.
> 
> Regards,
> Dave Blandston
> 
> 
I tested on my side and with recursion_limit 3, I got prety good result 
and no black area. Only difference: I used version 3.7 beta 34.

Some times, increasing max_trace_level can help. With 3.6, it sometimes, 
can help aleviate /some/ radiosity problems.



Alain

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