I've been experimenting with radiosity lately and also learning some Blender to
get my hands dirty with some mesh stuff.  This scene is all CSG though, except
for the famous Standford Bunny, which I got converted from .ply to Blender
format and then to povray with povanim.  Excellent tools.

The scene is actually meant to emulate a scene from a lighting study scene in:
http://www.tresd1.com.br/viewtopic.php?t=8557&start=0


yes, there actually is a ready-to-use 3DS file there that Blender is even able
to import, except everything is out-of-place after the import.  I found it
faster (and more fun) to just rewrite it in povray...

I played with various radiosity settings and am using fairily quality setting
with high rendering times:  this one took 2:55 hours in a P4 2.66...

I found it good-looking, despite the severely blown out floor... :)

eventually, I may try take 2...

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Attachments:
Download 'radiosity_and_bunnies.png' (149 KB)

Preview of image 'radiosity_and_bunnies.png'

The shadows are too sharp for such a huge area light.

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Warp <war### [at] tagpovrayorg> wrote:
> The shadows are too sharp for such a huge area light.

that's right!  There's no area_light and it took already 3 hours!  There's also
that horrible hemisphere spot where the ceiling touches the front wall.

I'll eventually add other furniture, area_light and play around the radiosity
settings.  And get rid of one of the bunnies!  The radiosity calculations get
stuck in the mesh for ages!

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nemesis wrote:
> Warp <war### [at] tagpovrayorg> wrote:
>> The shadows are too sharp for such a huge area light.
> 
> that's right!  There's no area_light and it took already 3 hours!  There's also
> that horrible hemisphere spot where the ceiling touches the front wall.

I usually get such artifacts when using reflection/refraction in my 
radiosity scene.

> I'll eventually add other furniture, area_light and play around the radiosity
> settings.  And get rid of one of the bunnies!  The radiosity calculations get
> stuck in the mesh for ages!

Hmm, is the bunny mesh unaltered? If so, you can play with the 
'decimate' modifier in Blender to reduce the number of triangles in the 
mesh. Since the bunnies are small, the scene won't suffer if the meshes 
are somewhat simpler.

It's a nice scene, at any rate. You're a patient guy (but not as patient 
as the ones who wait >day for a render! [I'm not one of them...]).

Sam

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stbenge <stb### [at] hotmailcom> wrote:
> I usually get such artifacts when using reflection/refraction in my
> radiosity scene.

there are none here, just simple ambient 0 diffuse something lambertian
surfaces.  Radiosity count was 80*4*2, error_bound .6/2 and nearest_count 12.
Next time, I'll try error_bound .6/3 and perhaps count 80*5*2...

> Hmm, is the bunny mesh unaltered? If so, you can play with the
> 'decimate' modifier in Blender to reduce the number of triangles in the
> mesh.

thanks!  That's a great tip!  The range scans are very high-resolution and I
guess trying to calculate diffuse interreflection between all those faces
really killed the radiosity.  It slowed to a crawl everytime it hit one of the
bunnies...

> It's a nice scene, at any rate.

thanks!  It's just a study.  But all the lighting and the rabbit looking
directly at it makes it feel like the poor fellow is being abducted by
aliens... ;)

> You're a patient guy (but not as patient
> as the ones who wait >day for a render! [I'm not one of them...]).

neither am I.  I'll try to get as many shortcuts and optimizations as possible.

I put it to render and proceeded to watch some Seinfeld episodes on DVD...

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nemesis nous apporta ses lumieres en ce 2008/01/14 09:06:
> Warp <war### [at] tagpovrayorg> wrote:
>> The shadows are too sharp for such a huge area light.
> 
> that's right!  There's no area_light and it took already 3 hours!  There's also
> that horrible hemisphere spot where the ceiling touches the front wall.
> 
> I'll eventually add other furniture, area_light and play around the radiosity
> settings.  And get rid of one of the bunnies!  The radiosity calculations get
> stuck in the mesh for ages!
> 
> 
Smooth mesh and radiosity with "normals on"? If so, remember that radiosity 
normals evaluation is slow, very slow.

-- 
Alain
-------------------------------------------------
BE ALERT!!!!  (The world needs more lerts ...)

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Alain <ele### [at] netscapenet> wrote:
> Smooth mesh and radiosity with "normals on"?

no normals at all in radiosity block.  But the mesh is reasonably dense.  Well,
I don't really know, first time I play with them...

I'll post the scene if anyone's interested in optimizing it and testing
different lighting and radiosity sets...

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"nemesis" <nam### [at] gmailcom> wrote:
> Alain <ele### [at] netscapenet> wrote:
> > Smooth mesh and radiosity with "normals on"?
>
> no normals at all in radiosity block.  But the mesh is reasonably dense.  Well,
> I don't really know, first time I play with them...
>
> I'll post the scene if anyone's interested in optimizing it and testing
> different lighting and radiosity sets...

I'd like to play around with the radiosity settings a bit if your ok with that.
Also I might try other lighting, specifically Jaime Vives Piqueres' Lightsys
system but I'm still learning how to use that.

Ian

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"binarycortex" <bin### [at] gmailcom> wrote:
> I'd like to play around with the radiosity settings a bit if your ok with that.
> Also I might try other lighting, specifically Jaime Vives Piqueres' Lightsys
> system but I'm still learning how to use that.

ok, here you go:
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.478f856641f9ed0f773c9a3e0%40news.povray.org%3E/

I'm still to add a table and possibly import the mesh for that beautiful
chair... eventually I'll update the scene...

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