After reading the lastest winner of the IRTC competitions diary of events, I
realised how much versatility POV had with other file formats.  I endevoured
to a little search and ended up with 3DWin and a downloaded obj file of a
beetle (no reason).  After converting it - complete with its layers to
moray - I found that with blobs the triangles arent filled in, making it
useless unless you want a wire frame, and smooth triangles, what I am
working with not smooth.  Any ideas or is this a general drawback?

Within the image, note the front of the car - and its not even the
compression

Pete

www.petecracknell.co.uk

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Attachments:
Download 'vwbeelte.jpg' (27 KB)

Preview of image 'vwbeelte.jpg'

It looks to me like the program has converted to smooth triangles, but 
has managed to completely screw the surface normals.

As far as fixing it goes, pass.  I've stopped playing with polygon 
meshes, and try to stick to either primitive based geometry or patch 
objects (from sPatch or hamaPatch)

Bye for now,
     Jamie.

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"Peter Cracknell" <pc### [at] lineonenet> wrote in message
news:3941892d@news.povray.org...
| with 3DWin and a downloaded obj file of a
| beetle (no reason).  After converting it - complete with its layers to
| moray - I found that with blobs the triangles arent filled in, making it
| useless unless you want a wire frame, and smooth triangles, what I am
| working with not smooth.  Any ideas or is this a general drawback?

Might use a little larger number for the Arc Step in Import Options before
loading the file in and try setting the Options for Export to a 80 degree
angle instead of the default of 70.  I never seem to get perfect conversions
but then I don't know what the original models look like either so maybe they
start off imperfect.  But I'd have to guess the conversion degrades most
anything some.
Btw, I think I've seen that car on the road someplace  :-)

Bob

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I've been using NuGraf/PolyTrans to convert models into POV smooth triangle
meshes, and it's flawless... perfectly smooth.  Only problem: it's
commercial and runs about 400-500 bucks.  The problem with your 3dwin output
is that it isn't breaking the model up into enough triangles, and it isn't
creating proper surface normals... not much you can do about that, the
problem is most likely within 3dwin.

-Doug Eichenberg

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I'll try wacking the angle up, thanks

Pete

Bob Hughes <per### [at] aolcom?subject=PoV-News:> wrote in message
news:39424912@news.povray.org...
> "Peter Cracknell" <pc### [at] lineonenet> wrote in message
> news:3941892d@news.povray.org...
> | with 3DWin and a downloaded obj file of a
> | beetle (no reason).  After converting it - complete with its layers to
> | moray - I found that with blobs the triangles arent filled in, making it
> | useless unless you want a wire frame, and smooth triangles, what I am
> | working with not smooth.  Any ideas or is this a general drawback?
>
> Might use a little larger number for the Arc Step in Import Options before
> loading the file in and try setting the Options for Export to a 80 degree
> angle instead of the default of 70.  I never seem to get perfect
conversions
> but then I don't know what the original models look like either so maybe
they
> start off imperfect.  But I'd have to guess the conversion degrades most
> anything some.
> Btw, I think I've seen that car on the road someplace  :-)
>
> Bob
>
>
>

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On Sat, 10 Jun 2000 01:20:38 +0100, "Peter Cracknell" <pc### [at] lineonenet>
wrote:

8< -------- snip ----

>After converting it - complete with its layers to
>moray - I found that with blobs the triangles arent filled in, making it
>useless unless you want a wire frame, and smooth triangles, what I am
>working with not smooth.  Any ideas or is this a general drawback?

Try using John VanSickle's SSS (Surface Subdivision Suite). It can a)
make the triangles smooth, b) interpolate the surface with more
triangles and (I think) c) output to Warp's compressed mesh format to
save disk space.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg

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"Peter Cracknell" <pc### [at] lineonenet> wrote in message
news:3941892d@news.povray.org...
>
> After converting it - complete with its layers to
> moray - I found that with blobs the triangles arent
> filled in, making it useless unless you want a wire
> frame, and smooth triangles, what I am working
> with not smooth.  Any ideas or is this a general
> drawback?

I've found that different converters work better/worse on different models.
Try using several different conversion programs and pick the one that does
the best job on that particular file.

Crossroads is pretty good.

http://home.europa.com/~keithr/Crossroads/index.html

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"I don't like it, and I'm sorry I ever had anything to do with it."
- Erwin Schrodinger talking about Quantum Mechanics.

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Doug Eichenberg wrote:
> 
> I've been using NuGraf/PolyTrans to convert models into POV smooth triangle
> meshes, and it's flawless... perfectly smooth.  Only problem: it's
> commercial and runs about 400-500 bucks.  The problem with your 3dwin output
> is that it isn't breaking the model up into enough triangles, and it isn't
> creating proper surface normals... not much you can do about that, the
> problem is most likely within 3dwin.

The "problem" with 3DWin is that it simply uses the existing triangles
or polygon point present in the original model. If it is a low poly
model then you will probably get faceting. Converting to smooth
triangles will help but it is not nearly as effecient as Polytrans
where it actually gives you the option of subdividing the surface
into more triangles for better object resolution.

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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