Zoly nous apporta ses lumieres en ce 2007/08/31 16:05:
> Thank you for tips.
> One clarification: may I remove AA from the first step as it will not affect 
> the values stored in the radiosity file?
AA and focal blur can be removed as they don't affect the radiosity data.
area_light can also be replaced by normal lights, even if they alter radiosity 
samples from the penumbrae regions.
> 
> I also just realized with more tests that if I use the same radiosity 
> parameters at both steps, the second one runs much faster. If I change 
> 'count', 'error_bound', 'recursion_limit' even to more relaxed values, it 
> takes more than double of the time to render.
> 
> Rgds,
> Zoly
If you change the settings, exept for pretrace_start/pretrace_end and 
always_sample off, you force new sampling with the new parameters. Those samples 
will be added to the loaded ones.
> 
> "Alain" <ele### [at] netscapenet> wrote in message 
> news:46d86fb9@news.povray.org...
>> Zoly nous apporta ses lumieres en ce 2007/08/31 12:49:
>>> Hi,
>>>
>>> I am finishing a set of scenes that make intensive use of radiosity as 
>>> the light comes from outside of the space that I am designing. To allow 
>>> more light to enter through the windows, I am applying radiosity in 2 
>>> steps:
>>>
>>> 1. Render without windows storing the radiosity info (save_file)
>> Windows without the "glass" pane.
>>> 2. Render with windows and reading the radiosity info from the file 
>>> (load_file).
>>>
>>> I have some doubts about how storing radiosity info works. I would 
>>> appreciate some lighting (in my mind):
>>>
>>> 1. What radiosity parameters have influence on the info that is stored in 
>>> the file (all of them?)
>> All of them.
>>> 2. What radiosity parameters have influence on the image if I am using 
>>> load_file?
>> Any can have an effect, when there is a need to gather some extra samples.
>>> 3. Does the info in the file overwrite the radiosity parameters in the 
>>> SDL code?
>> NO.
>>> 4. Can I make the first step at a lower size than the second step?
>> Absolutely. You can also remove any AA.
>>> 5. Does it matter where I put the parameters load_file and save_file in 
>>> the code (after the actual radiosity parameters, after them, ...?
>> load_file
>> radiosity parameters
>> save_file
>> or
>> radiosity parameters
>> load_file
>> save_file
>>
>> If you save_file before load_file, you may reload the data you just saved.
>>> 6. If I get some artifacts in the first step, may I remove them in the 
>>> second one?
>> The second step will gather additional samples if needed. They may, or 
>> not, remove or reduce those artefacts.
>> Use high quality parameters in the first pass, and more relaxed ones on 
>> the second pass.
>> In the first pass, remove any flat transparent, colorless, objects. 
>> Reflective objects should have the texture replaced by a plain white one 
>> IF they are far from bright surfaces: high ambient ones.
>> Keep shaped with ior or colored transparent objects as they actively 
>> change the radiosity samples. Also, keep non-flat reflective
>>> Thanks for your help,
>>> Zoly
>> If you also use photons, you must keep any object that is a target for the 
>> photons.
>>
>> -- 
>> Alain
>> -------------------------------------------------
>> You know you've been raytracing too long when you have ever brought your 
>> computer to its knees by mistakenly launching 64 simultaneous frames to be 
>> traced, while trying to maximizing the benefits of parallelizing them.
>> Carsten Whimster 
> 
> 


-- 
Alain
-------------------------------------------------
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