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behestelah
04-08-2010, 01:36 PM
I'm trying to subtract 8 different geometries from a box. After I subtract the geometries. The result looks great on Perspective view but on Front view (textured wire) 2 out of 8 subtracted area do not show!

Any insight would be greatly appreciated by this newly LW learner
Thanks

UnCommonGrafx
04-08-2010, 01:48 PM
Makes no diff if you see it in modeler or not; isn't the real question whether it will render or not?
You have, in the vernacular of the day, some whacked out, degenerate polys there. Means they have more than five points per polygon and the points don't sit in the same plane.
Sometimes those polys will render just fine. Other times, not. When not, tripling, shift-t, will correct things to a usable (often) state.

borkus
04-08-2010, 02:19 PM
Look here Pixel and Poly (http://www.pixelandpoly.com/video.html) and check out the video, "Cutting a subdivision / subpatch hole through a cube". It's referring to subpatch objects, but the principal is the same on even a regular polygonal surface. I've had so many headaches using booleans that since watching this video I haven't used them since. It's a bit more work, but you get used to it and I rarely have any surprises anymore when rendering.

BeeVee
04-08-2010, 03:25 PM
Richard Culver wrote a superb tutorial on subpatch modelling on LightWiki (http://www.lightwiki.com/Fundamentals_of_Subpatch_Modeling).

B

Revanto
04-08-2010, 08:14 PM
Working with booleans can be a messy business because the more you do it, the more 'unwanted' geometry can occur. Plus, sometimes things won't boolean correctly. Here are a few tips when working with booleans:

- Expect really messy results with lots of booleans so it can sometimes be better to use the result as a reference object to retopologise a new mesh

- Booleans work better with triangulated meshes. If a boolean doesn't work, you may need to triple the polygons in the areas that you will be working on

- It is sometimes better to boolean one mesh piece at a time as too many meshes will slow down your system and cause uglier combinations

- Merge your points (sometimes at a 1mm or 2mm radius), delete 1 and 2 point polygons and triple any 4-plus polygons after EACH boolean. This will help with each future boolean operations

- Booleans work best with closed meshes. If your mesh is open, temporarily create some polygons to cap the hole (give it a unique surface name) then you can delete those extra polygons after the boolean operation.

Anyway, I hope these tips are helpful. It's basically all the info I have gathered in my experiences with booleans.

Cheers,
Revanto :p

borkus
04-08-2010, 08:39 PM
Revanto brings up a very valid point in retopologising (sp). This is one of the prime reasons I'm looking into buying into 3dCoat despite having a license to Zbrush.

UnCommonGrafx
04-09-2010, 05:57 AM
Superb advice.
(much better than mine! lol)

behestelah
04-10-2010, 10:40 AM
I feel in debt to all of you. Great insights. You guys make this forum a unique place.
Thanks

Shnoze Shmon
04-10-2010, 11:04 AM
One thing that has helped me improve with the Boolean tool is learning to straiten my meshes out so rounder likes them. Meshes that rounder likes will probably fare well with Boolean. I think I use the stats window as much as the numeric window now.

Another lesson I learned the hard way. Never use add when you can use unify.

Revanto
04-10-2010, 08:25 PM
Revanto brings up a very valid point in retopologising (sp). This is one of the prime reasons I'm looking into buying into 3dCoat despite having a license to Zbrush.

3D coat was worth getting just for the retopology tools and the fact that you can unify meshes via voxels. It's not always perfect in both aspects but still worth it nonetheless. Sculptris (A free program) is definitely a next sculpting toy I like. Much better to sculpt in Sculptris than in 3d coat. Zbrush is great but it doesn't have the adaptive mesh capability.

Rev.

behestelah
04-15-2010, 07:57 PM
3D coat was worth getting just for the retopology tools and the fact that you can unify meshes via voxels. It's not always perfect in both aspects but still worth it nonetheless. Sculptris (A free program) is definitely a next sculpting toy I like. Much better to sculpt in Sculptris than in 3d coat. Zbrush is great but it doesn't have the adaptive mesh capability.

Rev.

Thanks for introducing the Sculptris, it's a great program.