POV-Ray : Newsgroups : povray.binaries.programming : UV-mapping - problems on surface edges. Server Time: 29 Sep 2020 22:48:13 GMT
  UV-mapping - problems on surface edges. (Message 1 to 4 of 4)  
From: Vahur Krouverk
Subject: UV-mapping - problems on surface edges.
Date: 13 Jun 1999 13:39:25
Message: <3763B492.E705A36@fv.aetec.ee>
Hello.

Hopfully this is not very wrong group, as it seems to be only binary
group, which has relevance for this message ;-)

I have problem with UV-mapping: it seems to me, that it does not work
correctly on surface edges. I use Rhino for creating surfaces and then
export them to .3DS and from it with Win3DS2POV to Pov-Ray format. 
Now, when I compare output from Rhino renderer and from PovRay, then it
could be seen, that on edges, where U and V have small values, texture
mapping is corrupted. I add 2 pictures to illustrate this problem. UV
values run in Rhino model from 0 (green-yellow corner) to 7 (red-blue
corner). 
Is this known problem and/or is there workaround for it? I tested it
with UVPov 5.2. If it helps, then I can send test files for it (texture
map, 3DS file, PovRay files).


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Attachments:
Download 'rho.jpg' (28 KB)
Download 'uvpov.jpg' (27 KB)

Preview of image 'rho.jpg'
rho.jpg

Preview of image 'uvpov.jpg'
uvpov.jpg


 

From: Nathan Kopp
Subject: Re: UV-mapping - problems on surface edges.
Date: 14 Jun 1999 03:21:29
Message: <37647484.42C3898B@Kopp.com>
Someone else had a similar problem, but I was unable to find the problem
at that point.  Hopefully I will this time.  That person was also doing
a Rhino->3ds->POV conversion, so the problem may be in one of the steps
of the conversion process.  But I won't rule out UV-Pov.  I'd rather
you not email the files (limited disk space on the server holding my
email), but if you could post here or in the scene-files group, I'll
take a closer look.

-Nathan

Vahur Krouverk wrote:
> 
> Hello.
> 
> Hopfully this is not very wrong group, as it seems to be only binary
> group, which has relevance for this message ;-)
> 
> I have problem with UV-mapping: it seems to me, that it does not work
> correctly on surface edges. I use Rhino for creating surfaces and then
> export them to .3DS and from it with Win3DS2POV to Pov-Ray format.
> Now, when I compare output from Rhino renderer and from PovRay, then it
> could be seen, that on edges, where U and V have small values, texture
> mapping is corrupted. I add 2 pictures to illustrate this problem. UV
> values run in Rhino model from 0 (green-yellow corner) to 7 (red-blue
> corner).
> Is this known problem and/or is there workaround for it? I tested it
> with UVPov 5.2. If it helps, then I can send test files for it (texture
> map, 3DS file, PovRay files).
> 
>   -------------------------------------------------------------------------------
>  [Image]  [Image]


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From: Thomas Baier
Subject: Re: UV-mapping - problems on surface edges.
Date: 14 Jun 1999 04:49:24
Message: <3764890a.1363563@news.povray.org>
Hi,

just download a new version of Win3dstopov at 

http://extra.newsguy.com/~tbaier/

I have found a curious bug with UV-mapping conversion.
Very small values are destroyed.

>Hello.
>
>Hopfully this is not very wrong group, as it seems to be only binary
>group, which has relevance for this message ;-)
>
>I have problem with UV-mapping: it seems to me, that it does not work
>correctly on surface edges. I use Rhino for creating surfaces and then
>export them to .3DS and from it with Win3DS2POV to Pov-Ray format. 
>Now, when I compare output from Rhino renderer and from PovRay, then it
>could be seen, that on edges, where U and V have small values, texture
>mapping is corrupted. I add 2 pictures to illustrate this problem. UV
>values run in Rhino model from 0 (green-yellow corner) to 7 (red-blue
>corner). 
>Is this known problem and/or is there workaround for it? I tested it
>with UVPov 5.2. If it helps, then I can send test files for it (texture
>map, 3DS file, PovRay files).


-tb


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From: Vahur Krouverk
Subject: Re: UV-mapping - problems on surface edges.
Date: 14 Jun 1999 15:56:24
Message: <37652636.1D34A74F@fv.aetec.ee>
Thomas Baier wrote:
> 
> Hi,
> 
> just download a new version of Win3dstopov at
> 
> http://extra.newsguy.com/~tbaier/
> 
> I have found a curious bug with UV-mapping conversion.
> Very small values are destroyed.
> 
> -tb

Thank You! This new version corrected the problem. Other Thank You for
writing textures to different file from objects: it was not easy to edit
files with size 12M.


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