Hi(gh)!

After fiddling around with the settings from rad_def.inc (and not 
getting near anything really looking good), I searched the Web for a 
tutorial on PoV-Ray radiosity and found this: 
http://www.simnet.is/hildurka/content/tut1page.htm

So I carefully worked through the steps described there - but when I 
came to the final setting (see code below), I noticed that my scene 
matched Mrs. Andresdottir's example scene as far as brightness of the 
shadowed parts is concerned - but still contained considerably more 
artifacts than her really clean scene (seventh from top, just above the 
version with area_light).

In her tutorial, Mrs. Andresdottir does not give the version of PoV-Ray 
she used, as her original code contains a switch for versions newer than 
3.1, I assume that it is 3.5 rather than 3.6 (which I use). Could it be 
that 3.5 uses different default radiosity settings than 3.6? Or is it 
because Mrs. Andresdottir places the whole scene inside an (monochrome) 
ambient 1 sphere rather than a gradiented sky_sphere?

Here is the code:

       radiosity
       {
         brightness 1.5
	count 300
	error_bound 0.05
         gray_threshold 0.8
         low_error_factor 0.2
         minimum_reuse 0.015
         nearest_count 10
	recursion_limit 5
         adc_bailout 0.01
         max_sample 0.9 // -1
         always_sample 1
	pretrace_start 0.08
	pretrace_end 0.01
         load_file "whatmough_residential.rad"
	save_file "whatmough_residential.rad"
       }

The only difference to Andresdottir's original code is that I use a 
gray_threshold of 0.8 rather than 0.

See you in Khyberspace!

Yadgar

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=?ISO-8859-1?Q?J=F6rg_=27Yadgar=27_Bleimann?= <yaz### [at] gmxde> wrote:
> So I carefully worked through the steps described there - but when I
> came to the final setting (see code below), I noticed that my scene
> matched Mrs. Andresdottir's example scene as far as brightness of the
> shadowed parts is concerned - but still contained considerably more
> artifacts than her really clean scene (seventh from top, just above the
> version with area_light).

I cannot explain why Andresdottir's render is cleaner than yours.  I can say
that, in my experience, a really tiny pretrace_end is good for reducing
artifacts.

> In her tutorial, Mrs. Andresdottir does not give the version of PoV-Ray
> she used, as her original code contains a switch for versions newer than
> 3.1, I assume that it is 3.5 rather than 3.6 (which I use). Could it be
> that 3.5 uses different default radiosity settings than 3.6? Or is it
> because Mrs. Andresdottir places the whole scene inside an (monochrome)
> ambient 1 sphere rather than a gradiented sky_sphere?

I have no experience with 3.1, so I can't comment on that.  It is not a question
of any difference in the defaults between 3.5 and 3.6, as all the parameters are
specified.  I do not recall any difference in output between 3.5 and 3.6.  I
don't think there's any difference between a sphere and a sky_sphere, although
someone else will have to confirm this.

I am no expert at radiosity, but I question some of Andresdottir's settings:

>          brightness 1.5

This is physically unrealistic.  A high brightness value can compensate for a
low recursion_limit, but that's obviously not the case here.  I suppose that
this looks more "realistic" because a straight rendering does not capture the
dynamic range of real-life lighting.

>  error_bound 0.05

I've found that setting error_bound this low does nothing more than slow down
your render, and perhaps add more intractable artifacts.

>  recursion_limit 5

See the tutorial in the documentation.  There's no reason to set recursion_limit
this high, unless you enjoy waiting for stuff.

>  pretrace_end 0.01

I found that this works well in 3.6, but when you upgrade to 3.7, it won't be
small enough for many scenes.

>          load_file "whatmough_residential.rad"
>  save_file "whatmough_residential.rad"

I'm not sure what it means to load_file and save_file at the same time.  (I
vaguely recall that there's some trick that this effects, but it wasn't
fantastic enough for me to retain it.)

Good luck!

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Hi(gh)!

On 24.10.2011 06:41, Cousin Ricky wrote:

> I cannot explain why Andresdottir's render is cleaner than yours.  I can say
> that, in my experience, a really tiny pretrace_end is good for reducing
> artifacts.

So I changed the pretrace_end to 0.002...

> I've found that setting error_bound this low does nothing more than slow down
> your render, and perhaps add more intractable artifacts.

...and increased error_bound to 0.1 - aside from the scene now rendering 
somewhat faster, I found no advantages, there are still the same 
annoying artifacts (see below)! Perhaps I really should try the ambient 
sphere...

See you in Khyberspace!

Yadgar

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Hi(gh)!

On 25.10.2011 18:40, Jörg 'Yadgar' Bleimann wrote:

> Perhaps I really should try the ambient
> sphere...

I tried this:

   sphere
   {
     0, 5000000
     texture
     {
       pigment { color rgb <0.5, 0.7, 1> }
       finish { diffuse 0 ambient 1 }
     }
     hollow
   }

...but it did not help either (see below)!

Note that I obviously made the sphere too large to be still visible 
(black sky), but at least radiosity was calculated...

See you in Khyberspace!

Yadgar

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Am 25.10.2011 18:40, schrieb Jörg 'Yadgar' Bleimann:
> So I changed the pretrace_end to 0.002...
...
> ....and increased error_bound to 0.1 - aside from the scene now
> rendering somewhat faster, I found no advantages, there are still the
> same annoying artifacts (see below)! Perhaps I really should try the
> ambient sphere...

What you really should try is POV-Ray 3.7 - radiosity has changed a lot 
since 3.6.

You'll probably need to increase the radiosity count parameter at any 
rate though; the irregularities seen on the walls indicate that POV-Ray 
doesn't "catch" the bright patches of sunlight on the floor reliably.

In case render times increase unacceptably, there are some ways in 3.7 
to counter this increase to some degree. (In particular, you can define 
fully transparent objects to "mark" the patches of sunlight, set to 
"radiosity { importance 1.0 } no_image no_shadow no_reflection", while 
you set the walls to "radiosity { importance 0.1 }" or some such.)

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High!

On 25.10.2011 22:07, clipka wrote:

> What you really should try is POV-Ray 3.7

O.k., I downloaded the source code package from www.povray.org - but 
then, I failed already after I unpacked the zip file. There is no such 
thing as "configure" on my system!

Perhaps I'm just too stupid to compile complex C++ code under Linux...

See you in Khyberspace!

Yadgar

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Am 25.10.2011 23:58, schrieb Jörg 'Yadgar' Bleimann:
> High!
>
> On 25.10.2011 22:07, clipka wrote:
>
>> What you really should try is POV-Ray 3.7
>
> O.k., I downloaded the source code package from www.povray.org - but
> then, I failed already after I unpacked the zip file.

That should be a *.tar.bz2 file actually. You won't get far with the 
Windows zip file on a Linux machine :-P

> There is no such thing as "configure" on my system!

There is - in the folder you extracted the POV-Ray sources to ;-) Just 
invoke "./configure" in that directory.

> Perhaps I'm just too stupid to compile complex C++ code under Linux...

... or you're simply not familiar with the typical procedures (yet).

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Hi(gh)!

On 26.10.2011 00:32, clipka wrote:

> That should be a *.tar.bz2 file actually. You won't get far with the
> Windows zip file on a Linux machine :-P

In fact it is! But I'm not even able to unpack the archive with ark 
correctly - all I get is an error message saying "libarchive is not able 
to process the archive file"!

See you in Khyberspace!

Yadgar

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Compare with this scene I happen to work on at this moment and rendered 
with version 3.7...

Thomas

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Am 26.10.2011 00:42, schrieb Jörg 'Yadgar' Bleimann:
> Hi(gh)!
>
> On 26.10.2011 00:32, clipka wrote:
>
>> That should be a *.tar.bz2 file actually. You won't get far with the
>> Windows zip file on a Linux machine :-P
>
> In fact it is! But I'm not even able to unpack the archive with ark
> correctly - all I get is an error message saying "libarchive is not able
> to process the archive file"!

I don't know that "ark" you're mentioning; do you mean arc? arj? ar? 
 From what I know, each of these three is specialized on one special 
type of compressed file respectively, none of which is the bzip2 format.

The traditional official way to extract the contents should be:

     bunzip2 povray-3.7.0.RC3.tar.bz2
     tar -xf povray-3.7.0.RC3.tar

The following single command should also do the job:

     tar -xjf povray-3.7.0.RC3.tar.bz2

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Hi(gh)!

On 26.10.2011 12:04, clipka wrote:

> tar -xjf povray-3.7.0.RC3.tar.bz2

This worked... but then the next problem: after ./configure 
COMPILED_BY="Jörg 'Yadgar' Bleimann <yaz### [at] gmxde>"

I got this:

This is an unofficial version compiled by:
  Jörg 'Yadgar' Bleimann <yaz### [at] gmxde>
The POV-Ray Team(tm) is not responsible for supporting this version.

Environment
-----------
checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
/bin/bash: /media/disk1part12/Software: No such file or directory
configure: WARNING: `missing' script is too old or missing
checking for a thread-safe mkdir -p... /bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether to enable maintainer-specific portions of Makefiles... no
checking whether $C_INCLUDE_PATH contains the "." path... no
checking whether $CPLUS_INCLUDE_PATH contains the "." path... no

Programs
--------
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for style of include used by make... GNU
checking dependency style of gcc... gcc3
checking how to run the C preprocessor... gcc -E
checking for grep that handles long lines and -e... /bin/grep
checking for egrep... /bin/grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking for stdlib.h... (cached) yes
checking for g++... g++
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking dependency style of g++... gcc3
checking whether the g++ compiler works... yes
checking how to run the C++ preprocessor... g++ -E
checking for C++ compiler vendor... gnu
checking for g++ version... 4.6
checking for ranlib... ranlib

Libraries
---------
checking whether to link with cygwin DLL... no
checking whether to enable static linking... no
checking for the pthreads library -lpthreads... no
checking whether pthreads work without any flags... no
checking whether pthreads work with -Kthread... no
checking whether pthreads work with -kthread... no
checking for the pthreads library -llthread... no
checking whether pthreads work with -pthread... yes
checking for joinable pthread attribute... PTHREAD_CREATE_JOINABLE
checking if more special flags are required for pthreads... no
checking for boostlib >= 1.37... configure: error: We could not detect 
the boost libraries (version 1.37 or higher). If you have a staged boost 
library (still not installed) please specify $BOOST_ROOT in your 
environment and do not give a PATH to --with-boost option.  If you are 
sure you have boost installed, then check your version number looking in 
<boost/version.hpp>. See http://randspringer.de/boost for more 
documentation.

All Greek to me! Really, it is the very first time in my life that I try 
to compile larger things than just a single-script C++ program...
Are there packages missing? Should I install the boost libraries? What 
are boost libraries?

See you in Khyberspace!

Yadgar

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On 10/26/2011 10:42 AM, Jörg 'Yadgar' Bleimann wrote:
> Hi(gh)!
>
> On 26.10.2011 12:04, clipka wrote:
>
>> tar -xjf povray-3.7.0.RC3.tar.bz2
>
> This worked... but then the next problem: after ./configure
> COMPILED_BY="Jörg 'Yadgar' Bleimann <yaz### [at] gmxde>"
>
> I got this:
>
> This is an unofficial version compiled by:
> Jörg 'Yadgar' Bleimann <yaz### [at] gmxde>
> The POV-Ray Team(tm) is not responsible for supporting this version.
>
> Environment
> -----------
> checking build system type... x86_64-unknown-linux-gnu
> checking host system type... x86_64-unknown-linux-gnu
> checking for a BSD-compatible install... /usr/bin/install -c
> checking whether build environment is sane... yes
> /bin/bash: /media/disk1part12/Software: No such file or directory
> configure: WARNING: `missing' script is too old or missing
> checking for a thread-safe mkdir -p... /bin/mkdir -p
> checking for gawk... gawk
> checking whether make sets $(MAKE)... yes
> checking whether to enable maintainer-specific portions of Makefiles... no
> checking whether $C_INCLUDE_PATH contains the "." path... no
> checking whether $CPLUS_INCLUDE_PATH contains the "." path... no
>
> Programs
> --------
> checking for gcc... gcc
> checking whether the C compiler works... yes
> checking for C compiler default output file name... a.out
> checking for suffix of executables...
> checking whether we are cross compiling... no
> checking for suffix of object files... o
> checking whether we are using the GNU C compiler... yes
> checking whether gcc accepts -g... yes
> checking for gcc option to accept ISO C89... none needed
> checking for style of include used by make... GNU
> checking dependency style of gcc... gcc3
> checking how to run the C preprocessor... gcc -E
> checking for grep that handles long lines and -e... /bin/grep
> checking for egrep... /bin/grep -E
> checking for ANSI C header files... yes
> checking for sys/types.h... yes
> checking for sys/stat.h... yes
> checking for stdlib.h... yes
> checking for string.h... yes
> checking for memory.h... yes
> checking for strings.h... yes
> checking for inttypes.h... yes
> checking for stdint.h... yes
> checking for unistd.h... yes
> checking for stdlib.h... (cached) yes
> checking for g++... g++
> checking whether we are using the GNU C++ compiler... yes
> checking whether g++ accepts -g... yes
> checking dependency style of g++... gcc3
> checking whether the g++ compiler works... yes
> checking how to run the C++ preprocessor... g++ -E
> checking for C++ compiler vendor... gnu
> checking for g++ version... 4.6
> checking for ranlib... ranlib
>
> Libraries
> ---------
> checking whether to link with cygwin DLL... no
> checking whether to enable static linking... no
> checking for the pthreads library -lpthreads... no
> checking whether pthreads work without any flags... no
> checking whether pthreads work with -Kthread... no
> checking whether pthreads work with -kthread... no
> checking for the pthreads library -llthread... no
> checking whether pthreads work with -pthread... yes
> checking for joinable pthread attribute... PTHREAD_CREATE_JOINABLE
> checking if more special flags are required for pthreads... no
> checking for boostlib >= 1.37... configure: error: We could not detect
> the boost libraries (version 1.37 or higher). If you have a staged boost
> library (still not installed) please specify $BOOST_ROOT in your
> environment and do not give a PATH to --with-boost option. If you are
> sure you have boost installed, then check your version number looking in
> <boost/version.hpp>. See http://randspringer.de/boost for more
> documentation.
>
> All Greek to me! Really, it is the very first time in my life that I try
> to compile larger things than just a single-script C++ program...
> Are there packages missing? Should I install the boost libraries? What
> are boost libraries?
>
> See you in Khyberspace!
>
> Yadgar
>

have a look at the files INSTALL and README in the root of your build 
directory ... tis all spelled out for ya!

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High!

On 26.10.2011 15:47, Jim Holsenback wrote:

> have a look at the files INSTALL and README in the root of your build
> directory ... tis all spelled out for ya!

In fact I did nothing else but reading through INSTALL.txt - 
http://www.povray.org/beta/source/unix-src-INSTALL.txt !

See you in Khyberspace!

Yadgar

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Am 26.10.2011 15:42, schrieb Jörg 'Yadgar' Bleimann:
> checking for boostlib >= 1.37... configure: error: We could not detect
> the boost libraries (version 1.37 or higher). If you have a staged boost
> library (still not installed) please specify $BOOST_ROOT in your
> environment and do not give a PATH to --with-boost option. If you are
> sure you have boost installed, then check your version number looking in
> <boost/version.hpp>. See http://randspringer.de/boost for more
> documentation.
>
> All Greek to me! Really, it is the very first time in my life that I try
> to compile larger things than just a single-script C++ program...
> Are there packages missing? Should I install the boost libraries? What
> are boost libraries?

Boost libraries := something you should install; check out your Linux 
distribution's package manager, it'll most likely have them. Make sure 
to also install the "developer" package for the boost libraries 
(probably named something like "boost-dev" or "boost-devel").

If you still experience problems even after installing the boost 
libraries, try adding the command-line option 
"--with-boost-thread=boost_thread-mt" to ./configure.

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High!

On 26.10.2011 22:55, clipka wrote:

> Boost libraries := something you should install; check out your Linux
> distribution's package manager, it'll most likely have them. Make sure
> to also install the "developer" package for the boost libraries
> (probably named something like "boost-dev" or "boost-devel").

But I did not know which boost packages exactly are necessary, I 
foolishly tried apt-get install boost* - which totally blew my system, 
the system partition ran full, and nothing worked anymore...

Meanwhile, I have mostly recovered from the crash - but I still do not 
now which boost packages to install...

See you in Khyberspace!

Yadgar

Now playing: Rio (Duran Duran)

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Hi(gh)!

On 25.10.2011 22:07, clipka wrote:

> What you really should try is POV-Ray 3.7 - radiosity has changed a lot
> since 3.6.

During the prolonged weekend, I stayed with a friend who in fact runs 
3.7 on his multi-processor systems - and even though I decreased count 
to 100 and upped error_bound to 0.15, the result (attached here) was 
much more satisfying than everything I achieved under 3.6!

See you in Khyberspace!

Yadgar

Now playing: September Gurls (Bangles)

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Am 02.11.2011 02:33, schrieb Jörg 'Yadgar' Bleimann:
> Hi(gh)!
>
> On 25.10.2011 22:07, clipka wrote:
>
>> What you really should try is POV-Ray 3.7 - radiosity has changed a lot
>> since 3.6.
>
> During the prolonged weekend, I stayed with a friend who in fact runs
> 3.7 on his multi-processor systems - and even though I decreased count
> to 100 and upped error_bound to 0.15, the result (attached here) was
> much more satisfying than everything I achieved under 3.6!

Now what did I tell you? :-)

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