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Converting Triangles to Quads
Posted: 30 October 2012 06:23 AM   [ Ignore ]
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I made a model musket to send to Shapeways—everything went fine and I got a lovely little inch-long musket back from them.
In the process of pre-flighting the model, I must have decimated the most detailed part of it—maybe zbrush did it when I ran it through for some checks, conversions, etc. Now I have a model that crashes Hexagon when trying to group it with other items or when trying to use displacement tools.
I have a backup, but I have made some very difficult edits to the tri-mesh figures since and don’t want to redo them.
Can I convert back to quad mesh easily? Meshlab crashes when I try, and zbrush says it’s going to, but doesn’t. Anything native to hexagon? Any other suggestions?

All the best,
Forrest Harris
Knuckleduster Miniatures

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Posted: 30 October 2012 06:39 AM   [ Ignore ]   [ # 1 ]
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Nothing in Hex afiak. Blender is probably your best bet but I don’t remember the method (just know there is one) and haven’t played with it to tell you how well or easily it works. I have seen some tutorials (which again unfortunately I don’t remember exactly which ones atm) which show converting some not totally simplistic meshes. If it’s a very high poly count though you may be out of luck. I would research the Blender method though.

The other thing to consider is disecting the model, converting smaller portions of the areas you want to keep in triangulated version and stitching them back into a copy of your non triangulated version.

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Posted: 30 October 2012 07:23 AM   [ Ignore ]   [ # 2 ]
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Thanks—I’ll download Blender. If I remember correctly, it also installs some programming thingy with it that might actually help meshlab work better!

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Posted: 30 October 2012 05:06 PM   [ Ignore ]   [ # 3 ]
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The problem when converting back to Quads from Triangles is you get a busted mesh and it looks like crap….

trueSpace can also convert from triangles to quads…Its complicated but can be done with your model selected and then you add a Primitive place the primitive close but not touching the model/mesh and then boolean the Primitive from the mesh/Model and bamm tS converts to quads…..Then you use a Box Primitive and then Boolen out have of your model…Leaving half,Select the NEW Face and then Mirror your Model…

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Posted: 30 October 2012 11:27 PM   [ Ignore ]   [ # 4 ]
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Blender is the only app I’ve come across which can do this reasonably well.  To convert the whole model, select it in object mode, switch to edit and Ctrl-j.  If it is complex or very dense, this may either not work at all, or leave you with some tri’s that you will have to convert manually.  To convert individual tri’s, in edit mode, select two adjacent tri’s and hit f - this removes the edge between them.

Edit - Sorry, my bad.  I meant Alt-j to convert tri’s to quads - be sure to have all facets selected..  Just checked the latest version of Meshlab - it no longer crashes converting tri’s to quad, but doesn’t do a very good job of it.

This dress was converted to quads in Blender - it did pretty good - no messing up, but there are still a lot of tri’s which would have to be converted by selecting adjacent tri’s and using f to remove the edge between the tri’s.

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Posted: 31 October 2012 06:34 AM   [ Ignore ]   [ # 5 ]
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I’m trying to get my bearings in Blender, but I’ll try that. I tried wrapping it in a unified skin in Zbrush, but the skin ended up triangles—I wonder if there is a setting to make unified skins quads? Trying Blender now.

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Posted: 31 October 2012 06:51 AM   [ Ignore ]   [ # 6 ]
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Just used Zbrush to get most tris eliminated—in Geometry, I used “equalize surface area” with triangles disabled. It still crashes Hexagon when doing displacement or welding, but I will download the new meshlab to find and clean up any remaining tris. I’ll post how it comes out!

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