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From: HadleyRille
Subject: Strange normal mangling issue
Date: 25 Feb 2009 13:25:01
Message: <web.49a58c5bb203a2a6483613820@news.povray.org>
I have a friend who's using POV-Ray to render a model I built for her.  I used
Poseray to convert it from a lwo to a POV scene.  I tested it, and was able to
get this using POV 3.6.1c under WindowsXP:

http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg

My friend takes the same scene, renders it using POV 3.6.1 under Linux, and gets
this:

http://homepage.mac.com/johnknoll/in/lores_aptera4.png

It sure looks like the normals are getting mangled, but it renders fine for me.
I expect that this is some issue with the linux build, but she claims to have
rendered many POV scenes including mesh objects and hasn't seen this issue
before.  The only difference here is that the model came from Poseray.  Any
thoughts about what might be going on, or what we might try to fix it?

Thank!


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From: Mike Hough
Subject: Re: Strange normal mangling issue
Date: 25 Feb 2009 13:33:53
Message: <49a58f11$1@news.povray.org>
Looks like the normals are not set smooth in the mesh. How does the model 
look in the preview window of poseray when you import it? If they don't look 
smooth, go to the "groups" tab and use the "recalculate normals" option in 
poseray.

Mike

"HadleyRille" <nomail@nomail> wrote in message 
news:web.49a58c5bb203a2a6483613820@news.povray.org...
>I have a friend who's using POV-Ray to render a model I built for her.  I 
>used
> Poseray to convert it from a lwo to a POV scene.  I tested it, and was 
> able to
> get this using POV 3.6.1c under WindowsXP:
>
> http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
>
> My friend takes the same scene, renders it using POV 3.6.1 under Linux, 
> and gets
> this:
>
> http://homepage.mac.com/johnknoll/in/lores_aptera4.png
>
> It sure looks like the normals are getting mangled, but it renders fine 
> for me.
> I expect that this is some issue with the linux build, but she claims to 
> have
> rendered many POV scenes including mesh objects and hasn't seen this issue
> before.  The only difference here is that the model came from Poseray. 
> Any
> thoughts about what might be going on, or what we might try to fix it?
>
> Thank!
>
>


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From: clipka
Subject: Re: Strange normal mangling issue
Date: 25 Feb 2009 15:30:01
Message: <web.49a5a976b967aba2c87a9d90@news.povray.org>
"HadleyRille" <nomail@nomail> wrote:
> http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
> http://homepage.mac.com/johnknoll/in/lores_aptera4.png
>
> It sure looks like the normals are getting mangled, but it renders fine for me.

"Mangled" is quite an understatement for *this* one...!

Check your auto-generated mesh2 object for number format issues (especially
decimal point vs. decimal comma, but also any other peculiarities). Maybe
Poseray did a lousy job there (using locale instead of forcing decimal point?),
and maybe the windows version of POV is more robust against that issue (possibly
using a compiler-dependent number parsing lib).

Did your friend use the same Poseray export, or did he export it again himself?


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From: HadleyRille
Subject: Re: Strange normal mangling issue
Date: 25 Feb 2009 19:00:00
Message: <web.49a5da5fb967aba483613820@news.povray.org>
I should be clear that the first image is what I get from POV under WindowsXP,
and the second image is what my friend gets from the same file under linux.
The preview looked good in Poseray.  It's a little hard for me to debug this,
since it works fine on my setup.  I've tried with and without normal
recomputation, makes no difference.

"Mike Hough" <nos### [at] nospamcom> wrote:
> Looks like the normals are not set smooth in the mesh. How does the model
> look in the preview window of poseray when you import it? If they don't look
> smooth, go to the "groups" tab and use the "recalculate normals" option in
> poseray.
>
> Mike
>
> "HadleyRille" <nomail@nomail> wrote in message
> news:web.49a58c5bb203a2a6483613820@news.povray.org...
> >I have a friend who's using POV-Ray to render a model I built for her.  I
> >used
> > Poseray to convert it from a lwo to a POV scene.  I tested it, and was
> > able to
> > get this using POV 3.6.1c under WindowsXP:
> >
> > http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
> >
> > My friend takes the same scene, renders it using POV 3.6.1 under Linux,
> > and gets
> > this:
> >
> > http://homepage.mac.com/johnknoll/in/lores_aptera4.png
> >
> > It sure looks like the normals are getting mangled, but it renders fine
> > for me.
> > I expect that this is some issue with the linux build, but she claims to
> > have
> > rendered many POV scenes including mesh objects and hasn't seen this issue
> > before.  The only difference here is that the model came from Poseray.
> > Any
> > thoughts about what might be going on, or what we might try to fix it?
> >
> > Thank!
> >
> >


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From: HadleyRille
Subject: Re: Strange normal mangling issue
Date: 25 Feb 2009 19:05:00
Message: <web.49a5dc56b967aba483613820@news.povray.org>
I don't see anything obviously wrong with the number formatting:

<0.1231928,0.913117,0.3886397>,
<0.2473599,0.8537122,0.4582451>,
<0.2138725,0.9033616,0.3717476>,
<0.4174524,0.808294,0.4152039>,
<0.3592963,0.8736917,0.3279772>,
<0,0.877506,0.4795656>,
<0,0.8864407,0.4628422>,

unless the "0," that leads the coordinate triplets of the last two lines screws
up the parser and it really needs to see 0.0 instead.  Seems unlikely, though.
I'll look for more subtle formatting weirdness, though.

To be clear, I did the Poseray conversion, and produced the first image.
Thinking it was all working well, I sent her the POV scene, and she replied
with the mangled image.

Thanks!

"clipka" <nomail@nomail> wrote:
> "HadleyRille" <nomail@nomail> wrote:
> > http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
> > http://homepage.mac.com/johnknoll/in/lores_aptera4.png
> >
> > It sure looks like the normals are getting mangled, but it renders fine for me.
>
> "Mangled" is quite an understatement for *this* one...!
>
> Check your auto-generated mesh2 object for number format issues (especially
> decimal point vs. decimal comma, but also any other peculiarities). Maybe
> Poseray did a lousy job there (using locale instead of forcing decimal point?),
> and maybe the windows version of POV is more robust against that issue (possibly
> using a compiler-dependent number parsing lib).
>
> Did your friend use the same Poseray export, or did he export it again himself?


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From: Thomas de Groot
Subject: Re: Strange normal mangling issue
Date: 26 Feb 2009 03:48:42
Message: <49a6576a$1@news.povray.org>
"HadleyRille" <nomail@nomail> schreef in bericht 
news:web.49a5dc56b967aba483613820@news.povray.org...
>
> To be clear, I did the Poseray conversion, and produced the first image.
> Thinking it was all working well, I sent her the POV scene, and she 
> replied
> with the mangled image.


...so, the only difference is windows POV vs linux POV...

My bet is with something in Linux.

Thomas


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From: Chris B
Subject: Re: Strange normal mangling issue
Date: 26 Feb 2009 04:36:45
Message: <49a662ad$1@news.povray.org>
"HadleyRille" <nomail@nomail> wrote in message 
news:web.49a58c5bb203a2a6483613820@news.povray.org...
>I have a friend who's using POV-Ray to render a model I built for her.  I 
>used
> Poseray to convert it from a lwo to a POV scene.  I tested it, and was 
> able to
> get this using POV 3.6.1c under WindowsXP:
>
> http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
>
> My friend takes the same scene, renders it using POV 3.6.1 under Linux, 
> and gets
> this:
>
> http://homepage.mac.com/johnknoll/in/lores_aptera4.png
>
> It sure looks like the normals are getting mangled, but it renders fine 
> for me.
> I expect that this is some issue with the linux build, but she claims to 
> have
> rendered many POV scenes including mesh objects and hasn't seen this issue
> before.  The only difference here is that the model came from Poseray. 
> Any
> thoughts about what might be going on, or what we might try to fix it?
>

Going from the top: Either the file got changed in some way between your 
machine and her machine, or it's a difference in the way the linux and 
windows builds deal with something in that particular file.

Check for errors/warnings in your message stream. Also check her message 
stream for any errors/warnings.

Try getting a copy of the misbehaving file back from her and rendering it on 
your machine. If you sent the file as a flat text file through email then 
it's possible that some part of the editing/emailing/saving process has made 
an operating system dependant or locale dependant change to the file. So try 
to use a different technique to get the file back (e.g. memory stick, or zip 
the file and send as binary). If you simply reverse the process you used to 
send the file then the change could get reversed , masking the cause, so 
using a very different technique to get the file back may help expose the 
cause.

If that fails, get her to post a copy of the misbehaving file on 
povray.text.scene-files or a compressed copy on povray.binaries.scene-files 
and I'm sure people will take a look at it for you to see if there's 
anything wrong with the format.

Regards,
Chris B.


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From: clipka
Subject: Re: Strange normal mangling issue
Date: 26 Feb 2009 04:45:01
Message: <web.49a66428b967abac3b204fd0@news.povray.org>
"HadleyRille" <nomail@nomail> wrote:
> I don't see anything obviously wrong with the number formatting:

Yes, looks perfectly fine. Did you check all sections though?

You say we're talking about POV 3.6.1 in all cases?

This is weird indeed. Would you mind sending me the scene file? I have both the
XP and Linux version here to check. Email to christoph#lipka-koeln,de (replace
the # and ,).


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From: HadleyRille
Subject: Re: Strange normal mangling issue
Date: 26 Feb 2009 11:35:01
Message: <web.49a6c3beb967aba483613820@news.povray.org>
"Chris B" <nom### [at] nomailcom> wrote:
> "HadleyRille" <nomail@nomail> wrote in message
> news:web.49a58c5bb203a2a6483613820@news.povray.org...
> >I have a friend who's using POV-Ray to render a model I built for her.  I
> >used
> > Poseray to convert it from a lwo to a POV scene.  I tested it, and was
> > able to
> > get this using POV 3.6.1c under WindowsXP:
> >
> > http://homepage.mac.com/johnknoll/in/aptera_pov_render.jpg
> >
> > My friend takes the same scene, renders it using POV 3.6.1 under Linux,
> > and gets
> > this:
> >
> > http://homepage.mac.com/johnknoll/in/lores_aptera4.png
> >
> > It sure looks like the normals are getting mangled, but it renders fine
> > for me.
> > I expect that this is some issue with the linux build, but she claims to
> > have
> > rendered many POV scenes including mesh objects and hasn't seen this issue
> > before.  The only difference here is that the model came from Poseray.
> > Any
> > thoughts about what might be going on, or what we might try to fix it?
> >
>
> Going from the top: Either the file got changed in some way between your
> machine and her machine, or it's a difference in the way the linux and
> windows builds deal with something in that particular file.
>
> Check for errors/warnings in your message stream. Also check her message
> stream for any errors/warnings.
>
> Try getting a copy of the misbehaving file back from her and rendering it on
> your machine. If you sent the file as a flat text file through email then
> it's possible that some part of the editing/emailing/saving process has made
> an operating system dependant or locale dependant change to the file. So try
> to use a different technique to get the file back (e.g. memory stick, or zip
> the file and send as binary). If you simply reverse the process you used to
> send the file then the change could get reversed , masking the cause, so
> using a very different technique to get the file back may help expose the
> cause.
>
> If that fails, get her to post a copy of the misbehaving file on
> povray.text.scene-files or a compressed copy on povray.binaries.scene-files
> and I'm sure people will take a look at it for you to see if there's
> anything wrong with the format.
>
> Regards,
> Chris B.

Thank you for these suggestions.  I'll follow up and report back.  I sent the
file in a zip archive originally, but we should eliminate the possibility that
the file has become corrupted.


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From: HadleyRille
Subject: Re: Strange normal mangling issue
Date: 26 Feb 2009 11:40:00
Message: <web.49a6c540b967aba483613820@news.povray.org>
Yes, I'm using 3.6.1c for 32 bit Windows, running under WindowsXP.  I downloaded
the compiled binary from povray.org/download a few days ago.

She's running:
Persistence of Vision(tm) Ray Tracer Version 3.6.1 (g++ 4.1.0 @
i686-redhat-linux-gnu)

I don't know if she compiled this herself from the source, or if she downloaded
the compiled binary.  I'll ask.

File has been sent, thanks!

-John

"clipka" <nomail@nomail> wrote:
> "HadleyRille" <nomail@nomail> wrote:
> > I don't see anything obviously wrong with the number formatting:
>
> Yes, looks perfectly fine. Did you check all sections though?
>
> You say we're talking about POV 3.6.1 in all cases?
>
> This is weird indeed. Would you mind sending me the scene file? I have both the
> XP and Linux version here to check. Email to christoph#lipka-koeln,de (replace
> the # and ,).


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