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Merge coplanar faces
Posted: 08 January 2013 03:41 PM   [ Ignore ]
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Hi!

I come from fractalforums.com because I have started to 3D print 3D fractals, and I need some 3D modeling tools in the middle of the process. I typically use Meshlab.

I’ve got a 5.5M faces mesh that I’d like to decimate to 1M. It’s got highly tesselated large flat areas and the “Merge coplanar faces” in Hexagon is exactly what I need. I have tested it on a smaller mesh, but the big one doesn’t even load (265 MB STL file)

Is there a practical limit in number of faces in Hexagon?

If yes, does anyone know a free program that can merge coplanar faces on large meshes? (Sketchup can do the job at DAE import time, but is too slow with large meshes)

I thought Meshlab would offer the option, but the closest filter is the quadric edge decimation and it’s not what I want, because it can affect edges and does not necessarily optimize planar areas.

Thanks!

bib

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Posted: 08 January 2013 08:03 PM   [ Ignore ]   [ # 1 ]
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Hey bib,

Welcome…

Hex definitely can not accommodate that high a level of mesh due to still being stuck in 32 bit world.  Even on my 64 bit rig with 6 G RAM, I can’t even push it to a couple hundred thousand.  I would love to see it handle even a million polys.

Regardless, I can’t help you on that front, but I can offer three software (free) that you might try.  Like Meshlab, they are geared for mesh fixing/altering/decimating.  Usually for triangle meshes like Delaunay, but I believe they can handle all quads (if your mesh is all quads).

Not sure if the first one supports STL, but they all support OBJ, OFF, and PLY.  If worse comes to worse, you might need to convert, and then convert back.  However, the last two do support STL, so no conversions necessary.  Getting them to load such a monstrous mesh might be another story, though.

*1) OpenFlipper:

http://www.openflipper.org/index.php?id=177

*2) ReMesh:

http://remesh.sourceforge.net/

*3) MeshMan:

http://www.holmes3d.net/graphics/meshman/


I hope this helps you.  Good luck…

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Take care all..        “It’s easy to clean up when you got money.”        *Old Post Count:  Don’t know, don’t care…  *New Site Status:  Doesn’t matter one iota.
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Posted: 09 January 2013 12:44 AM   [ Ignore ]   [ # 2 ]
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Thanks a lot for the links, I’ll try these. Meshlab imports/exports in all current formats and manages big files very well, unfortunately it does not do co-planar faces merging, or at least I could not find the feature.

Take care.

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Posted: 09 January 2013 03:46 AM   [ Ignore ]   [ # 3 ]
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Hi DaremoK3,

DaremoK3 - 08 January 2013 08:03 PM

Hex definitely can not accommodate that high a level of mesh due to still being stuck in 32 bit world.  Even on my 64 bit rig with 6 G RAM, I can’t even push it to a couple hundred thousand.  I would love to see it handle even a million polys.

Really?

To check I loaded a model I have into Hexagon 2.2 (its made of about 150 parts, but not finished yet lol). Total polygons 628,583 using 359 MB
Out of curiosity, I copied the model a number of times to see limits.

With LAA (Large Address Aware), I got to over 6 million polygons (6,285,830) and Hexagon used 3.7 GB of memory.
That is certainly not a poly_count I would like to work with in Hexagon on my current setup, but it is possible.

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Posted: 09 January 2013 12:52 PM   [ Ignore ]   [ # 4 ]
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I stand corrected…

Let me rectify.

On my system, if I try to work with high poly, or sub-d to high poly of over a couple hundred polys Hex crashes without fail every time, so I have just avoided any high poly work in Hex.

Steve, are you using the LAA application that was mentioned here somewhere last year?

I downloaded, but have yet to install, and do any testing in my 32 bit programs.  Been too busy with freelance work.

I’ll install in the future, and then give Hex a thorough testing hoping to be pleasantly surprised.

Thank you, Steve.


bib:

Well, Steve has proven that it is possible for Hex to handle big file meshes, so you might want to reevaluate your options to get it to work with your mesh.

Maybe you will be successful in loading the mesh using another format such as OBJ, and then convert back to STL once you have completed your work.  It’s worth a shot…


***EDIT:  Just did a quick test with a mesh I am working on.  Was able to get it to over half a million polys (with freeze), and the lag wasn’t that bad, but one more smoothing iterations pushed it to over 2.25 million polys, and Hex (internal) crashed.  My mesh disappeared, and Hex refuses to freeze mesh, or even display it (guess it is off somewhere in limbo-land).  Not a hard, fatal crash, but still unusable for me.

Note;  I’ve recently updated my graphics drivers.  Not sure if this helped Hex not fatal crashing on a couple smoothing iteration attempts, but at least I got the mesh to half a million workable state…

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Take care all..        “It’s easy to clean up when you got money.”        *Old Post Count:  Don’t know, don’t care…  *New Site Status:  Doesn’t matter one iota.
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Posted: 09 January 2013 01:28 PM   [ Ignore ]   [ # 5 ]
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DaremoK3 - 09 January 2013 12:52 PM

Steve, are you using the LAA application that was mentioned here somewhere last year?

Not sure what as been mentioned. The application I use (which I posted a link to 2 years ago on the old Bryce forums) , you can get from:- http://www.techpowerup.com/forums/showthread.php?t=112556 it does not require installing, just run it.

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Posted: 09 January 2013 05:57 PM   [ Ignore ]   [ # 6 ]
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I have used LAA with Hexagon, and I have been able to create models with millions of polys, as others have mentioned. However, once you have that many polys, it is sort of hit and miss with doing additional work, because there is no way to tell through the Hex interface if its actually working or hung. I have used booleans, which can take a very long time with something that big, but eventually they may produce a result. Or, they may hang Hexagon.

I have resorted to using task manager to watch the RAM usage to determine if Hex has crashed or hung, or is working and eventually will come back. Changing RAM usage (up or down) typically implies that Hex is working on something. However, if you see the RAM change repeatedly between a few specific values over and over, its hung and does not come back.

If the RAM usage stays at one number, it may do this for many minutes, and you might think it has crashed when its actually still working. If the number has not changed in 15 - 20 minutes its probably hung.

Hope this helps.

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Posted: 10 January 2013 07:22 AM   [ Ignore ]   [ # 7 ]
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DaremoK3 - 09 January 2013 12:52 PM

I stand corrected…


bib:

Well, Steve has proven that it is possible for Hex to handle big file meshes, so you might want to reevaluate your options to get it to work with your mesh.

Maybe you will be successful in loading the mesh using another format such as OBJ, and then convert back to STL once you have completed your work.  It’s worth a shot…

Thanks Daremok3. I tried again and always get an internal error. I’ll have to find alternatives…

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Posted: 10 January 2013 11:22 AM   [ Ignore ]   [ # 8 ]
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Hello all,  back from the living dead; well the Flu and I don’t mean man flu either.

Like Steve I was really surprised at such a low poly count causing a lock up;  So I also dug out an old mesh I have recently started to work on again.  I am using the 2.1 patched version as this is the one I started modelling this particular object in.  2.5.0.79 will not accept it at any price.  I am also employing a small prog’ which gives access to 4GB memory of my existing 12GB   Win 7 by the way. Below if it works shows the results.  Unfortunately, the sound levels are a tad high.  LOL.

http://screencast.com/t/TTCPMfUhfRm

LOL

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Cheers, Fanners.raspberry

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