"JSR" <jsr### [at] gmailcom> wrote:
> Hi,
> I have a problem with radiosity at 3400x1920 resolution.
> I use 2 pass radiosity: The first pass has deactivated transparency and
> reflections. In this pass there is no problem with radiosity and I save
> file information "scene.rad".
> In the second pass I activate transparency and reflections. If I render a
> test at 1700x960 all is correct, but when I render at 3400x1920 there is
> splotchiness.
>
> Source code:
>
> global_settings {
>   ambient_light 1.0
>   assumed_gamma 2.2
>   exposure 1.6
>   max_trace_level 6
>
>   #if (RAD)
>     radiosity {
>       brightness      2.0  //[1.0]
>       recursion_limit 2    //[3]
>       count           500  //[35]
>       error_bound     0.1  //[1.8]
>       gray_threshold  0.8  //[0.0]]
>
>       #if(SAVERAD)
>         save_file "scene.rad"
>       #else
>         pretrace_start 1
>         pretrace_end 1
>         load_file "scene.rad"
>         always_sample off
>       #end
>     }
>   #end
> }
>
> Any comments??
>
> Regards,
>
> Joel.

Hi Joel.

I am absolutely not a radiosity expert, lightyears from it, and I was
writing my post concerning a problem I have with rad when you posted yours!
At first look, I would increase the error_bound parameter. Too a low value
implies risk of splotchiness if the count parameter is not high enough. As
I think a count of 500 is very enough for your scene, try increasing
error_bound up to 0.5 or so, and decrease step by step if you really need
it. You may also play with pretrace_start and pretrace_end, the latter
could be determinant. You use default values (0.08 and 0.04 respectively).
Perhaps you could try one more pretrace step by setting pretrace_end to
0.02.

However, the problem might be something more subtle, requiring more
expertise ...

Unless you are a radiosity guru, this feature is a trial-and-fail approach.
Mainly fail for me ;o) ....

    Bruno

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