POV-Ray : Newsgroups : povray.binaries.images : smooth mesh outline artifacts fix Server Time
30 Jul 2024 00:27:04 EDT (-0400)
  smooth mesh outline artifacts fix (Message 1 to 5 of 5)  
From: clipka
Subject: smooth mesh outline artifacts fix
Date: 8 Jan 2013 18:41:33
Message: <50ecaead@news.povray.org>
One type of artifacts seen with smoothed meshes is dark specks, and/or 
the interior_texture poking through, at the mesh's outline; see the 
first image for an example.

Those artifacts can be avoided with a patch, as seen in the second 
image. (The one remaining red triangle is actually a hole in the mesh, 
not an artifact.)


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Attachments:
Download 'mesh_artifacts_37.png' (72 KB) Download 'mesh_artifacts_37_patched.png' (70 KB)

Preview of image 'mesh_artifacts_37.png'
mesh_artifacts_37.png

Preview of image 'mesh_artifacts_37_patched.png'
mesh_artifacts_37_patched.png


 

From: Thomas de Groot
Subject: Re: smooth mesh outline artifacts fix
Date: 9 Jan 2013 03:19:34
Message: <50ed2816$1@news.povray.org>
On 9-1-2013 0:41, clipka wrote:
> One type of artifacts seen with smoothed meshes is dark specks, and/or
> the interior_texture poking through, at the mesh's outline; see the
> first image for an example.
>
> Those artifacts can be avoided with a patch, as seen in the second
> image. (The one remaining red triangle is actually a hole in the mesh,
> not an artifact.)

Excellent. I noticed these artefacts indeed lately with the Satrap's 
veil: the interior_texture was partly poking through in places and I 
initially thought it was a modelling problem.

Thomas


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From: Jaime Vives Piqueres
Subject: Re: smooth mesh outline artifacts fix
Date: 9 Jan 2013 03:52:27
Message: <50ed2fcb$1@news.povray.org>

> One type of artifacts seen with smoothed meshes is dark specks,
> and/or the interior_texture poking through, at the mesh's outline;
> see the first image for an example.
>
> Those artifacts can be avoided with a patch, as seen in the second
> image. (The one remaining red triangle is actually a hole in the
> mesh, not an artifact.)

   Sweet... I sometimes resorted to insane subdivision levels to try to
avoid these.

   We need you to render regular scenes more often, so you can find
things to fix... ;)

   Thanks,

--
Jaime


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From: Kenneth
Subject: Re: smooth mesh outline artifacts fix
Date: 9 Jan 2013 07:00:01
Message: <web.50ed5b61cb9618f0c2d977c20@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:

>
> Those artifacts can be avoided with a patch...

That's quite amazing.

I had always thought that these kinds of anomalies were 'unfixable'--a natural
consequence of the smooth_triangle normals at the edges of objects. (As in 2.4.8
in the docs, "The shadow line artifact.") The only *partial* solution I've ever
found (which has been noted in the past) is the use of 'double_illuminate.' But
that was always kind of a kludge.

Your patch would be *most* welcome!! Nice work.


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From: clipka
Subject: Re: smooth mesh outline artifacts fix
Date: 9 Jan 2013 10:22:06
Message: <50ed8b1e$1@news.povray.org>
Am 09.01.2013 12:58, schrieb Kenneth:

> I had always thought that these kinds of anomalies were 'unfixable'--a natural
> consequence of the smooth_triangle normals at the edges of objects. (As in 2.4.8
> in the docs, "The shadow line artifact.") The only *partial* solution I've ever
> found (which has been noted in the past) is the use of 'double_illuminate.' But
> that was always kind of a kludge.

Make no mistake - these are only the artifacts at the outline; the 
classic shadow line artifacts are a trickier case.

> Your patch would be *most* welcome!! Nice work.

I'm sure it will find its way into POV-Ray proper. Not for 3.7.0 (the 
necessary changes go too deep), but I'd expect a 3.7.1 shortly after.


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