Hello:

Does anyone of you know whats the difference between these two by default
settings  for radiosity in POVRAY?:

Radiosity_OutdoorLQ
Radiosity_OutdoorHQ

For instance.
 The average number of iterations.
 The minumun distance before the coefficients are made equal to zero.
 The ambient and diffuse settings.


But mostly what are the differences in the algorithms used.

For instance a manual setting macro for radiosity looks like this:

global_settings {
    radiosity {
      pretrace_start 0.08
      pretrace_end   0.04
      count 35

      nearest_count 5
      error_bound 1.8
      recursion_limit 3

      low_error_factor 0.5
      gray_threshold 0.0
      minimum_reuse 0.015
      brightness 1

      adc_bailout 0.01/2
    }
  }

How would this compare to the other two "by default" quick settings?

Thank You in advance for any information on this.

Einar.

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einarabelc5 wrote:
> Hello:
> 
> Does anyone of you know whats the difference between these two by default
> settings  for radiosity in POVRAY?:
> 
> Radiosity_OutdoorLQ
> Radiosity_OutdoorHQ

You can just open the include file and check the settings made in the
declarations of the above.

	Thorsten

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Thorsten Froehlich <tho### [at] trfde> wrote:
> einarabelc5 wrote:
> > Hello:
> >
> > Does anyone of you know whats the difference between these two by default
> > settings  for radiosity in POVRAY?:
> >
> > Radiosity_OutdoorLQ
> > Radiosity_OutdoorHQ
>
> You can just open the include file and check the settings made in the
> declarations of the above.
>
>  Thorsten

Ok thanks, you mean povray.ini I suppose. What about the number of
iterations.

Post a reply to this message

Thorsten Froehlich <tho### [at] trfde> wrote:
> einarabelc5 wrote:
> > Hello:
> >
> > Does anyone of you know whats the difference between these two by default
> > settings  for radiosity in POVRAY?:
> >
> > Radiosity_OutdoorLQ
> > Radiosity_OutdoorHQ
>
> You can just open the include file and check the settings made in the
> declarations of the above.
>
>  Thorsten

Got it, rad_def.inc


does the count parameter indicates the number of iterations?

for example Radiosity_OutdoorLQ indicates a count of 80
and Radiosity_OutdoorHQ a count of 500

Thx again.

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einarabelc5 wrote:
  > does the count parameter indicates the number of iterations?
> 
> for example Radiosity_OutdoorLQ indicates a count of 80
> and Radiosity_OutdoorHQ a count of 500
> 
> Thx again.

Einar,

You might want to familiarize yourself with all of the keywords specific 
to radiosity. Here's a good starting point:

http://www.povray.org/documentation/view/3.6.1/271/

~Sam

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Samuel Benge <stb### [at] THIShotmailcom> wrote:
> einarabelc5 wrote:
>   > does the count parameter indicates the number of iterations?
> >
> > for example Radiosity_OutdoorLQ indicates a count of 80
> > and Radiosity_OutdoorHQ a count of 500
> >
> > Thx again.
>
> Einar,
>
> You might want to familiarize yourself with all of the keywords specific
> to radiosity. Here's a good starting point:
>
> http://www.povray.org/documentation/view/3.6.1/271/
>
> ~Sam

Thanks, you hit the nail.

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If you are using Megapov, see this excellent tutorial: 
http://www.imagico.de/pov/radiosity.html. Afaik, works also with latest 
Megapov and version 3.6.

Thomas

Post a reply to this message

einarabelc5 nous apporta ses lumieres en ce 2007/06/27 10:30:
> Hello:
> 
> Does anyone of you know whats the difference between these two by default
> settings  for radiosity in POVRAY?:
> 
> Radiosity_OutdoorLQ
> Radiosity_OutdoorHQ
Mostly, count.
> 
> For instance.
>  The average number of iterations.
>  The minumun distance before the coefficients are made equal to zero.
>  The ambient and diffuse settings.
> 
> 
> But mostly what are the differences in the algorithms used.
You always use the same algorithm, you only alter some parameters.
> 
> For instance a manual setting macro for radiosity looks like this:
> 
> global_settings {
>     radiosity {
>       pretrace_start 0.08
This set the initial dimention of the mosaic pretrace phase
>       pretrace_end   0.04
This set the final dimention of the pretrace step. The pretrace is used to 
pregather radiosity samples. A low pretrace_end can help you use lower settings 
elsewhere.
>       count 35
This is how many samples you want to collect. Importent quality parameter. Using 
any smaler value is not recomended.
> 
>       nearest_count 5
Number of close samples to average.
>       error_bound 1.8
Acceptable margin of error. High values give softer, smoother images, shadows 
will tend to be lighter. Low values give sharper, deeper shadows, demand that 
you increase the count value of the image will get splotchy. A quality parameter.
>       recursion_limit 3
How many times you want rays to bounce from object to object. Minimum of 1, 
normaly no object of using more than 5.
> 
>       low_error_factor 0.5
By how much the error_bound is multiplied during the final pretrace step.
>       gray_threshold 0.0
Increase this to reduce the effect of object's colour on it's environment. At 
default (0), a red object on a white plane will colour the plane red neer it. If 
set to 1, there will be no such colouring. Mostly aestetic parameter.
>       minimum_reuse 0.015
Importent quality factor. This is a good general default value, you rarely need 
to change it.
>       brightness 1
Changes the overall brightness of your scene. The highest the recursion_limit, 
the more effect it will have.
> 
>       adc_bailout 0.01/2
>     }
>   }
This is the same as global_settings{radiosity{}}
> 
> How would this compare to the other two "by default" quick settings?
This is the real defaults that are used if you use only radiosity{}. The others 
are "presets" from the rad_def.inc file, not defaults.
> 
> Thank You in advance for any information on this.
> 
> Einar.
> 
> 
> 
In any radiosity scene, you don't want ambient <> 0 in your finishes, unless you 
want the object to emit light (ambient>0) or "anti-light" (ambient<0).
I usualy add this: #default{finish{ambient 0 diffuse 1}} to my radiosity scenes. 
I also edited some includes to remove ambient from the various finishes.

-- 
Alain
-------------------------------------------------
E=MC^2.. I'm not fat! I'm energetic!

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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> If you are using Megapov, see this excellent tutorial:
> http://www.imagico.de/pov/radiosity.html. Afaik, works also with latest
> Megapov and version 3.6.

I think that's in the 3.6.1 documentation as well:

http://www.povray.org/documentation/view/3.6.1/103/

Tom

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