artifacts (pinched triangles)

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tortilla1

artifacts (pinched triangles)

Post by tortilla1 » Tue Oct 23, 2007 3:00 pm

After crunching I seem to get a lot of artifacts (pinched triangles, look like small black triangular shadows).
I recently installed the latest vesrion of polycruncher, and I have a feeling I get more then before.

How can I get rid of them/ reduce them ?


cheers

mootools
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Re: artifacts (pinched triangles)

Post by mootools » Tue Oct 23, 2007 4:22 pm

Hello,

I don't know what was your previous version but the algorithm does not change since 7.x
The enhancement consists in new feature provided with Polygon Cruncher such Confused point or Merge coplanar face tools.

Under some circumstance, planar optimization might inverts the face normal.
You may try to use the Merge coplanar face tool or to check Prevent normal inversion.

The next algorithm improvement will consist to remove such artifact.

I hope this help,
Manuel

PolyMonkey
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Re: artifacts (pinched triangles)

Post by PolyMonkey » Tue Jan 29, 2008 10:49 pm

I ran into a similar problem with polygon normal inversion. After some trail and error tests I found the when you import the optimized mesh (obj in this case) into 3DS Max, if you deselect "unify" it will prevent the normals from being flipped. When unify is selected and I import the origional mesh it works fine. It's only after I've used polygon cruncher and import an optimized mesh do I have the issue.

tester7

Re: artifacts (pinched triangles)

Post by tester7 » Mon Feb 18, 2008 10:18 am

Hi,

I'm getting this kind of problem (with the current trial)
(But if I draw normal 3DMAX cube and optimize it, that works..)

Original
Image

After 1% optimized (or even 0%)
Image

mootools
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Re: artifacts (pinched triangles)

Post by mootools » Fri Feb 22, 2008 5:17 pm

Hello,

I have to check that specific problem has it appears to be a border side effect of the new release.

Please verify that the Prevent normal inversion in the advanced tab is checked.
The last version now memorizes this setting (this was not the case for the previous one).
This means that - switching from 7.5 to 7.6 - could have made this setting being unchecked.

I hope this help,
Manuel

DougC
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Re: artifacts (pinched triangles)

Post by DougC » Wed Jul 30, 2008 5:25 pm

I just downloaded the demo and I'm getting a similar result to the first post. I've double checked all the settings mentioned above, converted it both ways and still get the same results. You could manually go in and fix these problems but as you can see on the left there are quite a few.

This model is coming from zbrush, are there any special setting you need to set in zbrush for export, or setting on import to max? I’m working on max 2009 btw.
Attachments
polycrunch_badtri.jpg
polycrunch_badtri.jpg (105.53 KiB) Viewed 23891 times

metalliandy
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Re: artifacts (pinched triangles)

Post by metalliandy » Sun Sep 21, 2008 1:25 pm

Hey all,

I am also have major problems with the artefacts shown by DougC.

Everything looks fine in the Polygon Cruncher view port but when i load the exported .obj i get the pinching as shown above.

I have the Prevent normal inversion checked.

Any ideas?

dirty deeds

Re: artifacts (pinched triangles)

Post by dirty deeds » Thu Sep 25, 2008 7:05 pm

This is a problem for me as well! In fact, I've never optimized a mesh w/PC without seeing these artifacts! I'm working with approx. the same workflow as well: ZB3 -> PC (via 3d photo browser) -> Max 2009 x64.

Same problem...

Re: artifacts (pinched triangles)

Post by Same problem... » Fri Sep 26, 2008 5:54 pm

I'm having the same problem--prevent normal inversion is checked.

Ian

Poly Optimus

Pinched Polys! Please Help!

Post by Poly Optimus » Fri Oct 24, 2008 10:32 pm

I have Polygon Cruncher 7.8 installed.
After importing an OBJ object into 3dsmax 2009, and polycrunching it.
The result show random various bad shaded polys. See image.
Please help!
Attachments
polycrunch_badtri.jpg
polycrunch_badtri.jpg (105.53 KiB) Viewed 23732 times

mootools
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Re: artifacts (pinched triangles)

Post by mootools » Thu Nov 06, 2008 12:36 am

Hello,

The pinched triangles might occurs on rare circumstances, particularly when there are planar surfaces.
A workaround can be to use the Merge Coplanar faces as a preprocess step in the Tools menu.

Anyway, I will work on that particular point for the next version of the algorithm.

Thanks,
Manuel

dirty deeds

Re: artifacts (pinched triangles)

Post by dirty deeds » Fri Nov 07, 2008 2:04 am

I see this in every single mesh I attempt to optimize. It is not rare in my case.

metalliandy
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Re: artifacts (pinched triangles)

Post by metalliandy » Sun Nov 30, 2008 8:22 pm

mootools wrote:Please could you post a small mesh where the problem appears?
I am nearly releasing the new version of Polygon Cruncher and that will help a lot.

Thanks,
Manuel
I have sent you a PM with the link my example is included.
Hope that helps :)

mootools
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Re: artifacts (pinched triangles)

Post by mootools » Mon Dec 08, 2008 5:15 pm

Many Thanks for your help.
Sure that it will help me to find out a solution and improve the algorithm.

Manuel

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