Re: [Algorithms] CSG operations on textured meshes -- something better than CGAL?
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Re: [Algorithms] CSG operations on textured meshes -- something better than CGAL?
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From: Vilya H. <vil...@gm...> - 2014-05-21 16:10:49
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Have you come across Carve CSG? The repository is here: https://code.google.com/p/carve/ I haven't used the library myself, but the website does mention that it handles interpolating texture coordinates (and other arbitrary attributes) correctly across the output mesh. Hope that's useful, Vil. On 21 May 2014 16:38, Eric Haines <eri...@gm...> wrote: > I'd certainly like to know, too. MeshLab might have one hiding in its > bowels, but I haven't looked hard enough yet. MeshMixer looks super-cool, > but appears to be just an application, not a library. > > > On Wed, May 21, 2014 at 11:05 AM, Jon Watte <jw...@gm...> wrote: > >> > You are going to be distorting triangles in different ways depending on >> the overall shape of the mesh at any given point though. >> > If you just retain existing UV coordinates for the new vertices, the >> results will be... strange. >> >> I do this operation with some frequency in 3ds Max, and it works the way >> I expect there. >> >> The 3ds Max boolean (and proboolean) modifier behavior would be good >> enough for my purposes, although they do have some edge cases and >> limitaitons (a k a "bugs" :-) >> But I don't want to buy a copy of 3ds Max per server that will be running >> this code, not to mention I want to run the servers on Linux. >> >> So, does anyone know of any textured-triangle-mesh CSG library out there, >> free or paid for, that would work? >> >> Sincerely, >> >> jw >> >> >> >> >> >> >> Sincerely, >> >> Jon Watte >> >> >> -- >> "I find that the harder I work, the more luck I seem to have." -- Thomas >> Jefferson >> >> >> On Tue, May 13, 2014 at 10:07 PM, James Robertson <ja...@os...>wrote: >> >>> You are going to be distorting triangles in different ways depending on >>> the overall shape of the mesh at any given point though. If you just >>> retain existing UV coordinates for the new vertices, the results will >>> be... strange. >>> >>> Consider the case where a convex region meets a concave one. One side >>> of the triangle will be slightly expanded, while the other side will be >>> contracted. Of course you know your input data better than us, so maybe >>> such distortions are acceptable or won't be noticeable, but they will be >>> there. >>> >>> >>> >>> On 14/05/2014 01:41, Jon Watte wrote: >>> >>> I don’t believe you will be able to use your existing uv values with >>>> the mesh that results from this csg operation >>> >>> >>> The operations I want to do are rigid and well conditioned and do not >>> stretch or generate new surfaces compared to the input meshes. They may >>> invert the winding of triangles, though (so normal maps would have to be >>> flipped) in the case of a cut-out. >>> I also need to preserve vertex bone weighting, too... something that can >>> preserve UV should be able to preserve that, too. Worst case, I put in a >>> vertex ID value in the UV channel and loop up the other parameters based on >>> that. >>> >>> So... no general purpose parameterized trimesh CSG library available? >>> >>> Sincerely, >>> >>> jw >>> >>> >>> >>> >>> >>> Sincerely, >>> >>> Jon Watte >>> >>> >>> -- >>> "I find that the harder I work, the more luck I seem to have." -- >>> Thomas Jefferson >>> >>> >>> On Thu, May 8, 2014 at 12:28 PM, Chris Green <cg...@va...>wrote: >>> >>>> I don’t believe you will be able to use your existing uv values with >>>> the mesh that results from this csg operation – it has a different >>>> topology, and there will be changes in the ratios of the areas of different >>>> parts of the model, with really bumpy areas of the mesh being smoothed out, >>>> etc. You’ll even have brand new areas emerge that don’t have corresponding >>>> areas on the original model, as holes are filled in, etc. >>>> >>>> >>>> >>>> What might work better is to just do the csg operation and generate a >>>> uv atlas for the resultant mesh. You can then generate a new texture map >>>> for this uv parametization by sampling from the original one, in a similar >>>> manner to the way in which people produce bumpmaps mapping the normals of >>>> highly tessellated models onto low-detail models. >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> *From:* Jon Watte [mailto:jw...@gm...] >>>> *Sent:* Thursday, May 08, 2014 11:08 AM >>>> *To:* Game Development Algorithms >>>> *Subject:* [Algorithms] CSG operations on textured meshes -- something >>>> better than CGAL? >>>> >>>> >>>> >>>> I have a triangle mesh composed of many submeshes with different >>>> textures/materials. This mesh may not be a 2-manifold -- it may have open >>>> edges. Typical game art. >>>> >>>> >>>> >>>> I now want to create a 3mm thick shell of this mesh. As an >>>> approximation, taking each triangle, and extrude it back along the normal >>>> of each vertex, and union all of those generated chopped pyramids would be >>>> an approximation of what I want. If I do literally that, and self-union the >>>> result, then that should resolve the self-intersection problems I'll run >>>> into along narrow sharp creases etc. >>>> >>>> >>>> >>>> I can't find any library to do this, though. CGAL has some fairly >>>> robust functions on NEF polyhedra, but those polyhedra don't seem to allow >>>> parameterization (which is academic speak for texture coordinates that may >>>> have discontinuities across edges.) >>>> >>>> >>>> >>>> So, what are some robust CSG libraries available that work on such >>>> game-style meshes, preserving texture coordinates? >>>> >>>> >>>> >>>> (And actually, I don't have one such mesh; I have > 120 million such >>>> meshes, so a by-hand or even script-the-Max-shell-modifier solution is >>>> unlikely to work. I do have hundreds of Linux servers at my disposal, >>>> though.) >>>> >>>> >>>> >>>> Sincerely, >>>> >>>> Jon Watte >>>> >>>> >>>> -- >>>> "I find that the harder I work, the more luck I seem to have." -- >>>> Thomas Jefferson >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Is your legacy SCM system holding you back? Join Perforce May 7 to find >>>> out: >>>> • 3 signs your SCM is hindering your productivity >>>> • Requirements for releasing software faster >>>> • Expert tips and advice for migrating your SCM now >>>> http://p.sf.net/sfu/perforce >>>> _______________________________________________ >>>> GDAlgorithms-list mailing list >>>> GDA...@li... >>>> https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >>>> Archives: >>>> >>>> http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list >>>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >>> Instantly run your Selenium tests across 300+ browser/OS combos. >>> Get unparalleled scalability from the best Selenium testing platform available >>> Simple to use. Nothing to install. Get started now for free."http://p.sf.net/sfu/SauceLabs >>> >>> >>> >>> _______________________________________________ >>> GDAlgorithms-list mailing lis...@li...https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >>> Archives:http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list >>> >>> >>> >>> >>> ------------------------------ >>> <http://www.avast.com/> >>> >>> This email is free from viruses and malware because avast! Antivirus<http://www.avast.com/>protection is active. >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >>> Instantly run your Selenium tests across 300+ browser/OS combos. >>> Get unparalleled scalability from the best Selenium testing platform >>> available >>> Simple to use. Nothing to install. Get started now for free." >>> http://p.sf.net/sfu/SauceLabs >>> _______________________________________________ >>> GDAlgorithms-list mailing list >>> GDA...@li... >>> https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >>> Archives: >>> http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list >>> >> >> >> >> ------------------------------------------------------------------------------ >> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >> Instantly run your Selenium tests across 300+ browser/OS combos. >> Get unparalleled scalability from the best Selenium testing platform >> available >> Simple to use. Nothing to install. Get started now for free." >> http://p.sf.net/sfu/SauceLabs >> _______________________________________________ >> GDAlgorithms-list mailing list >> GDA...@li... >> https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >> Archives: >> http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list >> > > > > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. > Get unparalleled scalability from the best Selenium testing platform > available > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list > |
