Nicolas Alvarez wrote:

>> I forgot to add that the machine is only running XP 32 bit and 32 bit
>> POV which
>> is why I wondered if approaching the 2GB memory limit may be causing the
>> problem.
> 
> It definitely won't cause the problems on the image; but what a waste!
> 8GB of RAM and you can only use 2GB of them? Get a 64-bit system :)

  Yeah, what a waste. What's the point of even having 8 gigabytes when
you can't use them?

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Warp <war### [at] tagpovrayorg> wrote:
> Nicolas Alvarez wrote:

> >> I forgot to add that the machine is only running XP 32 bit and 32 bit
> >> POV which
> >> is why I wondered if approaching the 2GB memory limit may be causing the
> >> problem.
> >
> > It definitely won't cause the problems on the image; but what a waste!
> > 8GB of RAM and you can only use 2GB of them? Get a 64-bit system :)
>
>   Yeah, what a waste. What's the point of even having 8 gigabytes when
> you can't use them?

It's not my machine (just a development PC where I work that is really under
utilised..). Currently it needs to be on 32 bit XP for comparisson to the live
environment. However, I am hoping I can change this to 64 bit XP soon.

And I can't wait for Pov 3.7 with 8 cores to use...

Sean

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Hello,

These look the same radiosity artifacts I get with POV 3.7b. It's a bug 
with the current (beta quality) radiosity calculation.

To get rid of them I just lower the count until they disappear. Of 
course, this will reduce the overall quality, but you can compensate by 
introducing a slight normal to the surfaces and keeping a low 
error_bound. I hope this helps.

Sam

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> These look the same radiosity artifacts I get with POV 3.7b. It's a bug 
> with the current (beta quality) radiosity calculation.

Interesting; since the original poster didn't say what POV-Ray version 
he was using.

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stbenge <stb### [at] hotmailcom> wrote:
> Hello,
>
> These look the same radiosity artifacts I get with POV 3.7b. It's a bug
> with the current (beta quality) radiosity calculation.
>
> To get rid of them I just lower the count until they disappear. Of
> course, this will reduce the overall quality, but you can compensate by
> introducing a slight normal to the surfaces and keeping a low
> error_bound. I hope this helps.
>
> Sam

Hi Sam,

Thanks for the info but this is version 3.6. I avoided 3.7 as I know the
radiosity feature is not working correctly yet.

Sean

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"s.day" <s.d### [at] uelacuk> wrote in message 
news:web.47da42f3d387c8867eb3d110@news.povray.org...
> stbenge <stb### [at] hotmailcom> wrote:
>> Hello,
>>
>> These look the same radiosity artifacts I get with POV 3.7b. It's a bug
>> with the current (beta quality) radiosity calculation.
>>
>> To get rid of them I just lower the count until they disappear. Of
>> course, this will reduce the overall quality, but you can compensate by
>> introducing a slight normal to the surfaces and keeping a low
>> error_bound. I hope this helps.
>>
>> Sam
>
> Hi Sam,
>
> Thanks for the info but this is version 3.6. I avoided 3.7 as I know the
> radiosity feature is not working correctly yet.
>
> Sean
>

Hi Sean,

I only say this because I didn't see anyone else mention it, but I imagine 
you've checked that it's not just the old coincident surfaces chessnut 
(which catches me out with embarrassing regularity).

Regards,
Chris B.

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"Chris B" <nom### [at] nomailcom> wrote:

> Hi Sean,
>
> I only say this because I didn't see anyone else mention it, but I imagine
> you've checked that it's not just the old coincident surfaces chessnut
> (which catches me out with embarrassing regularity).
>
> Regards,
> Chris B.


Hi Chris,

No it is not coincident surfaces (although I too have suffered with these many
times).

I have rendered this scene before (for povcomp) and it rendered OK.
The only differences with this render are higher radiosity setting and higher
resolution. The render I submitted to povcomp was without isosurfaces turned on
but I have also rendered at 1600x1200 with isosurfaces. (this version can be
found here:
http://news.povray.org/povray.binaries.images/thread/%3Cweb.42885c9a31d5b4de79fdcb760%40news.povray.org%3E/?ttop=266991
&toff=2000
).

For the 1600x1200 render I gathered radiosity stats at 800x600.

I was planning to do the final render at 5250x3500 and gather radiosity stats at
2625x1750.

Sean

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s.day wrote:
> For the 1600x1200 render I gathered radiosity stats at 800x600.
> 
> I was planning to do the final render at 5250x3500 and gather radiosity stats at
> 2625x1750.

Care to post your radiosity step 2 (after gathering) setting?  I 
personally never get quite the results I want if I render both steps at 
different resolutions and my step 2 settings work best like these:

   load_file "tmp.rad"
   minimum_reuse 0
   count 1
   error_bound EB+.1
   low_error_factor 1
   recursion_limit 1
   pretrace_start 1
   pretrace_end 1
   nearest_count 1

EB is error_bound from step 1.  It goes slightly smoother like this.

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Hmmm.... All this guessing...

S. Day, my suggestion is, that you publish the entire scene code and related 
graphics and INI files. This would allow us, to have some persons working on 
your scene to find out where the problem is.

Once we can try and try again, you should get soon an exact answer. I hope, 
this suggestion is okay for you. Once the black holes are fixed, your scene 
will become a beautiful scene.

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nemesis <nam### [at] nospamgmailcom> wrote:
> Care to post your radiosity step 2 (after gathering) setting?  I
> personally never get quite the results I want if I render both steps at
> different resolutions and my step 2 settings work best like these:
>
>    load_file "tmp.rad"
>    minimum_reuse 0
>    count 1
>    error_bound EB+.1
>    low_error_factor 1
>    recursion_limit 1
>    pretrace_start 1
>    pretrace_end 1
>    nearest_count 1
>
> EB is error_bound from step 1.  It goes slightly smoother like this.

Hi,

I have had similar issues to you but find rendering at 50% of the final
width/height to usually be acceptable (although comparissons may show that
rendering with 50% the radiosity quality at the correct resolution will be just
as good..).

I do not normally specify much for the second pass just set:

pretrace_start 1
pretrace_end 1
error_bound = same as step 1 (although I might try your technique in future).
recursion_limit = same as step 1
always_sample off

I do not really understand the radiosity settings very well I have a rough idea
of how most of them work but tend to resort to trial and error more than
educated guessing..

Sean

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