POV-Ray : Newsgroups : povray.general : RADIOSITY save/load syntax in v3.7-3.8? Server Time: 25 Jan 2021 23:56:59 GMT
  RADIOSITY save/load syntax in v3.7-3.8? (Message 1 to 9 of 9)  
From: Kenneth
Subject: RADIOSITY save/load syntax in v3.7-3.8?
Date: 22 Nov 2020 14:50:10
Message: <web.5fba799d449c7afd98418910@news.povray.org>
[I'm running the latest v3.8 Windows 'development' build of POV-ray.]

Does anyone know the updated proper syntax for LOADING a saved radiosity data
file?  I tried doing a search of the newsgroups, but I have not found anything
useful. I haven't used radiosity very much in the past, but I'm trying to catch
up ;-)

For SAVING radiosity data, POV-ray's built-in documentation and the online wiki
have the following instructions, for use in an .INI file:

Radiosity_File_Name="RAD data" (or whatever file name you choose)
Radiosity_To_File=on

*Both* of these need to be used to create a saved rad-data file, and they
successfully work.

But for re-LOADING the saved file for use in the scene, the instructions have
apparently never been finalized-- the syntax as given does not work...
            Radiosity_From_File=<on/off>
although the docs do say that the syntax is "subject to change."

By experimenting, I found some syntax that *appears* to work -- at least, it
does not cause a fatal error:
              Radiosity_From_File="RAD data"
I don't know if there is a 2nd command that also needs to be used; the docs
don't mention one.

However, in running tests with this syntax, it seems that the saved data file is
not being used at all. The only way that I know to test this is to creat a scene
with initial radiosity settings that take a long time to render (while SAVING
the *large* rad-data file), and then to try to re-load the file for a subsequent
render. The result is that the 2nd render takes just as long to complete as the
first-- so I have to assume that the saved rad file is not being used.

I also tried  +RFI on the command line, per the documentation, but the re-render
completely fails: "Runtime library Invalid Parameter Handler Invoked"

Has anyone found alternate command-line settings for loading the file that will
actually work? Does this command successfully work in LINUX builds of the source
code?

The other important question is: What should the scene's rad settings be when
RE-rendering the scene with the saved file? Are they supposed to be left as-is?
Or modified? This has always been a mystery to me, and I have not yet found
anything in the documentation that would be a clue. (I tried using a 'blank'
radiosity block--  radiosity{} -- but that ignores the saved data as well.)


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From: Thomas de Groot
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 23 Nov 2020 07:45:08
Message: <5fbb6884$1@news.povray.org>
Op 22/11/2020 om 15:48 schreef Kenneth:
> 
> [I'm running the latest v3.8 Windows 'development' build of POV-ray.]
> 
> Does anyone know the updated proper syntax for LOADING a saved radiosity data
> file?  I tried doing a search of the newsgroups, but I have not found anything
> useful. I haven't used radiosity very much in the past, but I'm trying to catch
> up ;-)
> 
> For SAVING radiosity data, POV-ray's built-in documentation and the online wiki
> have the following instructions, for use in an .INI file:
> 
> Radiosity_File_Name="RAD data" (or whatever file name you choose)
> Radiosity_To_File=on
> 
> *Both* of these need to be used to create a saved rad-data file, and they
> successfully work.
> 
> But for re-LOADING the saved file for use in the scene, the instructions have
> apparently never been finalized-- the syntax as given does not work...
>              Radiosity_From_File=<on/off>
> although the docs do say that the syntax is "subject to change."
> 
> By experimenting, I found some syntax that *appears* to work -- at least, it
> does not cause a fatal error:
>                Radiosity_From_File="RAD data"
> I don't know if there is a 2nd command that also needs to be used; the docs
> don't mention one.
> 
> However, in running tests with this syntax, it seems that the saved data file is
> not being used at all. The only way that I know to test this is to creat a scene
> with initial radiosity settings that take a long time to render (while SAVING
> the *large* rad-data file), and then to try to re-load the file for a subsequent
> render. The result is that the 2nd render takes just as long to complete as the
> first-- so I have to assume that the saved rad file is not being used.
> 
> I also tried  +RFI on the command line, per the documentation, but the re-render
> completely fails: "Runtime library Invalid Parameter Handler Invoked"
> 
> Has anyone found alternate command-line settings for loading the file that will
> actually work? Does this command successfully work in LINUX builds of the source
> code?
> 
> The other important question is: What should the scene's rad settings be when
> RE-rendering the scene with the saved file? Are they supposed to be left as-is?
> Or modified? This has always been a mystery to me, and I have not yet found
> anything in the documentation that would be a clue. (I tried using a 'blank'
> radiosity block--  radiosity{} -- but that ignores the saved data as well.)
> 
> 

I have used the features a couple of times with the following ini code:

// +w285 +h424 -a +am2 +bm2 Radiosity_File_Name="Samples.rad" +RFO
// +w855 +h1272 +a0.1 +am2 +bm2 +wt6 Radiosity_File_Name="Samples.rad" +RFI

*Note the difference of image size for saving and reading!!!* That will 
gain you much render time for the same final result. As far as I am 
aware, the rad settings remain the same for both renders, and povray 
takes care of doing things right (or so I have understood it). I have no 
idea about linux.

-- 
Thomas


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From: Ash Holsenback
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 23 Nov 2020 11:54:02
Message: <5fbba2da$1@news.povray.org>
On 11/22/20 9:48 AM, Kenneth wrote:
> 
> [I'm running the latest v3.8 Windows 'development' build of POV-ray.]
> 
> Does anyone know the updated proper syntax for LOADING a saved radiosity data
> file?  I tried doing a search of the newsgroups, but I have not found anything
> useful. I haven't used radiosity very much in the past, but I'm trying to catch
> up ;-)
> 
> For SAVING radiosity data, POV-ray's built-in documentation and the online wiki
> have the following instructions, for use in an .INI file:
> 
> Radiosity_File_Name="RAD data" (or whatever file name you choose)
> Radiosity_To_File=on
> 
> *Both* of these need to be used to create a saved rad-data file, and they
> successfully work.
> 
> But for re-LOADING the saved file for use in the scene, the instructions have
> apparently never been finalized-- the syntax as given does not work...
>              Radiosity_From_File=<on/off>
> although the docs do say that the syntax is "subject to change."
> 
> By experimenting, I found some syntax that *appears* to work -- at least, it
> does not cause a fatal error:
>                Radiosity_From_File="RAD data"
> I don't know if there is a 2nd command that also needs to be used; the docs
> don't mention one.
> 
> However, in running tests with this syntax, it seems that the saved data file is
> not being used at all. The only way that I know to test this is to creat a scene
> with initial radiosity settings that take a long time to render (while SAVING
> the *large* rad-data file), and then to try to re-load the file for a subsequent
> render. The result is that the 2nd render takes just as long to complete as the
> first-- so I have to assume that the saved rad file is not being used.
> 
> I also tried  +RFI on the command line, per the documentation, but the re-render
> completely fails: "Runtime library Invalid Parameter Handler Invoked"
> 
> Has anyone found alternate command-line settings for loading the file that will
> actually work? Does this command successfully work in LINUX builds of the source
> code?
> 
> The other important question is: What should the scene's rad settings be when
> RE-rendering the scene with the saved file? Are they supposed to be left as-is?
> Or modified? This has always been a mystery to me, and I have not yet found
> anything in the documentation that would be a clue. (I tried using a 'blank'
> radiosity block--  radiosity{} -- but that ignores the saved data as well.)
> 
> 

i have theses two definitions in Options.ini:

[RadiosityLoad]
Declare=UseRad=1
Radiosity_File_Name="/users/ash/POV-Ray/v3.8/Source/Work.rad"
+RFI
+RFO

[RadiositySave]
Declare=UseRad=2
Radiosity_File_Name="/users/ash/POV-Ray/v3.8/Source/Work.rad"
+RFO

they get called on the command line

in the scene file if loading saved rad data, set pretrace_start and 
pretrace_stop to 1 and add RadiosityLoad to the command line

in the scene file if saving rad data, set pretrace_start and 
pretrace_stop to preferred settings and add RadiositySave to the command 
line

hint: if / else blocks are your friend


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From: Bald Eagle
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 23 Nov 2020 19:10:00
Message: <web.5fbc085d4489f50e1f9dae300@news.povray.org>
Maybe this might be of some help?

http://www.ignorancia.org/index.php/technical/tools-objects/2-pass-radiosity/


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From: Kenneth
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 23 Nov 2020 21:45:01
Message: <web.5fbc2c5b4489f50ed98418910@news.povray.org>
THANKS Thomas and Ash for giving me the clues I needed; I got the loading of the
radiosity data to work, in an .INI file. Happy days! (But the +RFO and +RFI
comand-line terms simply don't work in the 3.8 version I am using.)

To SAVE the rad data to a file:
Radiosity_File_Name="RAD data" (or whatever name)
Radiosity_To_File=on

To LOAD the saved file:
Radiosity_File_Name="RAD data" [I didn't realize that this needed to be
specified again]
Radiosity_From_File=on

Simple! Although, I think the documentation could be a bit clearer about the
need for Radiosity_File_Name in *both* cases. BTW, I haven't yet tried this
syntax in v3.7.0. And the "RAD data" file , when loaded, apparently doesn't need
the .rad file extension, at least when used in an .INI file.

From experimenting, I agree with Thomas that a scene's radiosity settings should
be left as-is when loading the saved file, with no modifications. Here's why:

Given these original settings as an example...
Radiosity{
brightness 1.0
count 200
recursion_limit 3
minimum_reuse 0.0001
maximum_reuse 0.0013
pretrace_start 0.08
pretrace_end 0.01
always_sample off [the default]
}

....if I modify one or more of those terms, the re-rendered image with the saved
file shows a strange combination of settings. For example, changing COUNT from
200 to 1 creates a visual 'mix' of both counts, which is hard to describe. And
even stranger, changing RECURSION_LEVEL to 1 rather than 3 takes five times
longer to render than the initial scene(!). Normally, a lower recursion_level
will produce a *faster* render. Very strange.

The point is, changing any parameter seems to change the behavior and visual
result of the saved file, in unexpected ways. Some changes are obvious, some are
subtle. However, as Ash mentioned, changing PRETRACE_END to 1.0 (and maybe
PRETRACE_START as well?) has a useful effect: It apparently keeps any 'new'
radiosity samples from being taken. (I had to run some animation tests to see
this.) Even with ALWAYS_SAMPLE off, the original values for those two terms
produce a few more samples. That probably improves the quality of a still image,
but it adversely affects radiosity in *animations*, as I've discovered. Using
1.0 for both terms (along with the saved file) really helps to keep animation
from 'jittering'.

I've also discovered an interesting limitation in rad behavior that I didn't
know about, when used in animation. But I've come up with a useful solution-- to
keep the radiosity 'light patches' steady and unchanging, with no 'flicker'.
:-)   I'll save that for a separate post.


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From: Thomas de Groot
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 24 Nov 2020 07:39:19
Message: <5fbcb8a7$1@news.povray.org>
Op 23/11/2020 om 20:07 schreef Bald Eagle:
> 
> Maybe this might be of some help?
> 
> http://www.ignorancia.org/index.php/technical/tools-objects/2-pass-radiosity/
> 
> 

There is also this discussion I forgot about:

">3C4e81db88@news.povray.org%3E/" target="_new">http://news.povray.org/povray.general/thread/%3C4e81db88@news.povray.org%3E/

which may or may not be of interest here. I forgot about those pretrace_ 
and _end set to 1 in the second pass. I suppose this works also for v3.8

-- 
Thomas


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From: Kenneth
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 24 Nov 2020 13:55:04
Message: <web.5fbd0f704489f50ed98418910@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:

>
> There is also this discussion I forgot about:
>
> ">3C4e81db88@news.povray.org%3E/" target="_new">http://news.povray.org/povray.general/thread/%3C4e81db88@news.povray.org%3E/
>

">3C4e81db88@news.povray.org%3E/" target="_new">http://news.povray.org/povray.general/thread/%3C4e81db88@news.povray.org%3E/

Thanks for that (and to Bald Eagle for his link as well.) I didn't know about
this '2-pass' radiosity method for still image renders. Although, those
recommendations (from 2011) appear to be based on using v3.6 of POV-ray, I
think; perhaps Jaime's original Ignorancia article is too(?) AFAIU, radiosity's
inner workings have undergone some major changes since then, for v3.7-3.8, so I
wonder if the information is still valid for later versions. That would require
some comparison tests, to find out.


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From: Bald Eagle
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 24 Nov 2020 18:40:01
Message: <web.5fbd529f4489f50e1f9dae300@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
> Thanks for that (and to Bald Eagle for his link as well.) I didn't know about
> this '2-pass' radiosity method for still image renders. Although, those
> recommendations (from 2011) appear to be based on using v3.6 of POV-ray, I
> think; perhaps Jaime's original Ignorancia article is too(?) AFAIU, radiosity's
> inner workings have undergone some major changes since then, for v3.7-3.8, so I
> wonder if the information is still valid for later versions. That would require
> some comparison tests, to find out.

I was using that method for my Secret Passage TC-RTC entry, which is filed under
POV-Ray/v3.7, and my .pov file has #version 3.7; at the top.
Also, the image metadata for the final render says "Created By POV-Ray 3.7.0",
so I'm confident that it works with 3.7.
There could be some changes in 3.8, but I would imagine that the overall
workflow ought to be the same.


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From: Kenneth
Subject: Re: RADIOSITY save/load syntax in v3.7-3.8?
Date: 24 Nov 2020 19:50:08
Message: <web.5fbd62934489f50ed98418910@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
>
> Given these original settings as an example...
> Radiosity{
> brightness 1.0
> count 200
> recursion_limit 3
> minimum_reuse 0.0001
> maximum_reuse 0.0013
> pretrace_start 0.08
> pretrace_end 0.01
> always_sample off [the default]
> }
>

BTW, my reason for choosing these particular minimum_reuse and maximum_reuse
values is based on what I perceive to be a ratio, approximately 1:13, which is
the same ratio as the default values...
           minimum_reuse 0.015
           maximum_reuse 0.2

I assume that the defaults were chosen for a reason; and from experimenting, it
looks like my own values reproduce the same *kind* of effect, only on a smaller
scale (for more detail in object corners, etc.) So this radiosity block is my
preferred choice, at the moment ;-) With whatever COUNT value I choose.


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