POV-Ray : Newsgroups : povray.pov4.discussion.general : Real-micro-poly-displacement based on patterns and pictures Server Time: 26 Jun 2019 20:47:00 GMT
  Real-micro-poly-displacement based on patterns and pictures (Message 1 to 10 of 10)  
From: H  Karsten
Subject: Real-micro-poly-displacement based on patterns and pictures
Date: 18 Nov 2009 03:30:00
Message: <web.4b03699294dd874dda6353d60@news.povray.org>
When like to have displacement instead of bump-mapping, you need to use
iso-surfaces.

Having real-micro-poly-displacement like having a normal{}, or a finish{} for
every object would be cool.

BTW.: The PixarRenderman uses real-micro-poly-displacement to generate
motion blur instead of multisampling of objects like MegaPov does. Its extreme
fast and the quality is *much* better. First and foremost, if you compare the
render times of these options, having the same quality.

Holger


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From: Nicolas Alvarez
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 18 Nov 2009 03:44:30
Message: <4b036d9e$1@news.povray.org>
"H. Karsten" <h-karsten()web.de> wrote:
> Having real-micro-poly-displacement like having a normal{}, or a finish{}
> for every object would be cool.

That's not possible. "poly-displacement" only works if you have polygons to 
begin with. POV-Ray doesn't use polygons for most of its objects.


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From: H  Karsten
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 18 Nov 2009 04:40:01
Message: <web.4b0379a1886514d6da6353d60@news.povray.org>
Nicolas Alvarez <nic### [at] gmailcom> wrote:
...
> That's not possible. "poly-displacement" only works if you have polygons to
> begin with. POV-Ray doesn't use polygons for most of its objects.

I know, that the PixarRenderman can real displace also objects, that are
defined, using the RIB-Language, such as spheres or boxes.

A micropolygon is that part of an surface, that appears in the very pixel of the
image. (Every pixel builds a polygon) I don't know, if its based on normal
polygons. In the Renderman, you can displace *everything* except media. And a
lot of object are definitely _not_ polygon-based, like NURBS or patches. The
surface appears of other formulas (see posting before) +the
displacement-algorithm.

Maybe, its just the name of 'micropolygon' the may confuse.

Holger


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From: Warp
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 18 Nov 2009 16:49:27
Message: <4b042597@news.povray.org>
H. Karsten <h-karsten()web.de> wrote:
> Having real-micro-poly-displacement like having a normal{}, or a finish{} for
> every object would be cool.

  You are free to offer an implementation of this.

-- 
                                                          - Warp


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From: H  Karsten
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 18 Nov 2009 18:20:01
Message: <web.4b043a10886514d6da6353d60@news.povray.org>
Warp <war### [at] tagpovrayorg> wrote:
...
>
> You are free to offer an implementation of this.
>
> --
> - Warp

Until now, I'm not able to compile PovRay without an error message ;)

OK, one time it works. My C skill is on the level, making shader in PovMan...


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From: clipka
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 19 Nov 2009 02:34:42
Message: <4b04aec2$1@news.povray.org>
H. Karsten schrieb:

> Until now, I'm not able to compile PovRay without an error message ;)
> 
> OK, one time it works. My C skill is on the level, making shader in PovMan...

C++ skills would be closer to the mark ;-)


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From: H  Karsten
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 19 Nov 2009 04:40:01
Message: <web.4b04cb76886514d6da6353d60@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
...
> C++ skills would be closer to the mark ;-)

Well then it seams, that I'm ++ behind ;)


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From: Chambers
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 21 Nov 2009 16:45:11
Message: <4b081917$1@news.povray.org>
Actually, everything in Renderman is a polygon.  Even if you use curve 
based objects like spheres, they first get tessellated as polygons 
before being rendered.

I believe Pixar uses a dynamic tessellation which yields polygons 
roughly half the size of individual pixels, so the end quality is still 
quite good, but that doesn't change the fact that the way POV-Ray works 
is very, very different.

...Chambers


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From: nemesis
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 25 Nov 2009 06:06:28
Message: <4b0cc964@news.povray.org>
Chambers wrote:
> Actually, everything in Renderman is a polygon.  Even if you use curve 
> based objects like spheres, they first get tessellated as polygons 
> before being rendered.
> 
> I believe Pixar uses a dynamic tessellation which yields polygons 
> roughly half the size of individual pixels, so the end quality is still 
> quite good, but that doesn't change the fact that the way POV-Ray works 
> is very, very different.

Yes, REYES is basically scanline.  It wasn't until quite a few years ago 
  that Renderman integrated raytracing into its pipeline.


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From: nemesis
Subject: Re: Real-micro-poly-displacement based on patterns and pictures
Date: 25 Nov 2009 06:07:51
Message: <4b0cc9b7$1@news.povray.org>
clipka wrote:
> H. Karsten schrieb:
> 
>> Until now, I'm not able to compile PovRay without an error message ;)
>>
>> OK, one time it works. My C skill is on the level, making shader in 
>> PovMan...
> 
> C++ skills would be closer to the mark ;-)

Advanced math/geometry skills more likely.


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