POV-Ray : Newsgroups : povray.binaries.images : Subsurface Scattering: macro now available (21kb jpeg) Server Time
19 Nov 2024 10:31:35 EST (-0500)
  Subsurface Scattering: macro now available (21kb jpeg) (Message 1 to 7 of 7)  
From: Samuel Benge
Subject: Subsurface Scattering: macro now available (21kb jpeg)
Date: 26 Nov 2003 18:38:51
Message: <3FC5397E.1020307@hotmail.com>
Okay. For whoever is interested, I have placed the code into 
povray.binaries.scene-files. There is an example file (see image 
attached to this message) as well as an include file containing the macro.

There are still a few things that could be modified, but it should work 
well in most cases, where the scattered light doesn't have to be 
extra-smooth.

Have fun~

-- 
Samuel Benge

stb### [at] hotmailcom
See my website@: http://www.goldrush.com/~abenge/Top/index.html


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From: Gilles Tran
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 26 Nov 2003 18:58:51
Message: <3fc53e3b$1@news.povray.org>

news:3FC### [at] hotmailcom...
> Okay. For whoever is interested, I have placed the code into
> povray.binaries.scene-files. There is an example file (see image
> attached to this message) as well as an include file containing the macro.

This is simply brilliant! Thanks a lot (I'm selfishly glad that you finally
got a more permanent internet connection... Rare as it was, your input was
always impressive)!
Just wondering: how did you came up with this idea? It seems to be a case
example of "thinking out the box"...

And for the potential developers: could this be hard coded for faster
rendering?
Also: could a trick like this be used to create patina effects?

G.


-- 
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters


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From: Samuel Benge
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 26 Nov 2003 19:38:53
Message: <3FC5479B.1010305@hotmail.com>
Gilles Tran wrote:

> This is simply brilliant!


Thank you. You know, in-between posting the preliminary images, I kept 
on thinking you might like to use this technique. You're an inspiration 
to all POVers.... you know that, right? :)

> Thanks a lot (I'm selfishly glad that you finally
> got a more permanent internet connection... 


If I can find a job soon, I can keep my ISP.

> Rare as it was, your input was
> always impressive)!


I'm terrible about being a stable presence. The problem is, I only post 
when I'm sufficiantly inspired, and sometimes I take vacations from POV 
for months; it's not all because I can't keep an ISP.


> Just wondering: how did you came up with this idea? It seems to be a case
> example of "thinking out the box"...


That's a tricky question. For some reason everything I learn about 
POV-Ray gets stored in my memory better than most things, which makes 
for a good pool of ideas to pull from. Somehow, this idea came as a 
flash one night before bed.

 
> And for the potential developers: could this be hard coded for faster
> rendering?
> Also: could a trick like this be used to create patina effects?

 > G.

This *can* be hard-coded. A setup similar to the current implementation 
of photons would do the trick, but instead of making them pass through 
in refraction or bounce off in reflection, they would simply stick onto 
the object's surface and blur out.



-- 
Samuel Benge

stb### [at] hotmailcom
See my website@: http://www.goldrush.com/~abenge/Top/index.html


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From: Hughes, B 
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 26 Nov 2003 23:15:21
Message: <3fc57a59@news.povray.org>
"Samuel Benge" <sbe### [at] hotmailcom> wrote in message
news:3FC### [at] hotmailcom...
> Okay. For whoever is interested, I have placed the code into
> povray.binaries.scene-files. There is an example file (see image
> attached to this message) as well as an include file containing the macro.

Yea!

> There are still a few things that could be modified, but it should work
> well in most cases, where the scattered light doesn't have to be
> extra-smooth.

Nice rendered example. Great chew-toy too.

Bob H.


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From: Christoph Hormann
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 27 Nov 2003 04:45:16
Message: <kktg91-8o2.ln1@triton.imagico.de>
Samuel Benge wrote:
> [...]
> 
> This *can* be hard-coded. A setup similar to the current implementation 
> of photons would do the trick, but instead of making them pass through 
> in refraction or bounce off in reflection, they would simply stick onto 
> the object's surface and blur out.

This 'scattering photon mapping' is definitely an interesting idea.  I 
don't know it it will work efficiently in practice but that's difficult 
to tell.  Note that it is a completely different approach towards 
scattering than usual.

But your blob based technique could be much more efficient with Chris 
Huff's blob pattern.  This way you would avoid the need for the multiple 
object patterns and don't need a slow proximity pattern either.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 25 Oct. 2003 _____./\/^>_*_<^\/\.______


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From: Samuel Benge
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 27 Nov 2003 13:45:55
Message: <3FC64661.7070303@hotmail.com>
The problem with the way I shot the blobs at the surface is that they 
are just randomly shot at the surface. Photon-mapping has a more 
efficient way of doing this. The photons are shot at the target object 
in a spiral pattern, and therefore cover the surface more completely 
with fewer samples.

Chris Huff's blob pattern would be a great benefit. Is that part of 
MegaPovPlus? If so, I could get started on something right away :).

Christoph Hormann wrote:

> 
> This 'scattering photon mapping' is definitely an interesting idea.  I 
> don't know it it will work efficiently in practice but that's difficult 
> to tell.  Note that it is a completely different approach towards 
> scattering than usual.
> 
> But your blob based technique could be much more efficient with Chris 
> Huff's blob pattern.  This way you would avoid the need for the multiple 
> object patterns and don't need a slow proximity pattern either.
> 
> Christoph
> 


-- 
Samuel Benge

stb### [at] hotmailcom
See my website@: http://www.goldrush.com/~abenge/Top/index.html


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From: Christoph Hormann
Subject: Re: Subsurface Scattering: macro now available (21kb jpeg)
Date: 27 Nov 2003 14:22:06
Message: <54vh91-76g.ln1@triton.imagico.de>
Samuel Benge wrote:
> The problem with the way I shot the blobs at the surface is that they 
> are just randomly shot at the surface. Photon-mapping has a more 
> efficient way of doing this. The photons are shot at the target object 
> in a spiral pattern, and therefore cover the surface more completely 
> with fewer samples.

Then try placing the blob components in a similar way.  You don't 
necessarily need a spiral pattern, other regular patterns or random but 
uniform distributions like used for radiosity might be useful as well. 
Try for example the halton sequence Mael used for radiosity some time ago.

> Chris Huff's blob pattern would be a great benefit. Is that part of 
> MegaPovPlus? If so, I could get started on something right away :).

It is part of MegaPOV 0.x.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 25 Oct. 2003 _____./\/^>_*_<^\/\.______


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