On Tue, Nov 10, 2009 at 11:08 AM, Joe Doliner <[email protected]> wrote: > I think that this problem isn't so much intractable as it is not precisely > defined. Are you hoping to intersect two surfaces and get the intersection > curve between them? If so BRL-CAD should be able to handle that fairly well. > However if you want to actually perform boolean operations treating the > surfaces as the boundaries of 3d solids. Then unless they're watertight > there isn't a well defined interior and exterior. Which means intersections > stop making sense. Sorry if I'm being stupid and don't understand what's > going on here.
Thanks for the quick reply, Joe. You're not being stupid, in fact you extracted a lot of sense from my vague email. Here's a specific example of the problem I'm trying to solve: lets' say you have a watertight, triangulated solid and want to slice it in half with a plane. Can BRL-CAD generate the resulting solid (or two) that would be created by this procedure? More generally, I will have one watertight solid and one surface that may or may not be a solid, but will definitely be manifold and have well defined normals at every vertex. The second surface may or may not intersect the first; if it does, I'd like to be able to extract the intersecting volume or, at worst, the line of intersection of the two surfaces. Currently, I have a stand-alone program that reads in OBJ files, generates "r_bot_internal" structures with the "mode" set to RT_BOT_SOLID and performs boolean operations on them. This works swimmingly as long as all the OBJs represent watertight manifold solids. Using the RT-BOT_SURFACE mode or the RT_BOT_PLATE mode gives errors, even in circumstances when I'd expect the boolean operation to succeed. Is there any code that comes in the BRL-CAD distro (I'm using version 7.16.0) that demonstrates the use of boolean geometry operations on surfaces or plates? -Jeff ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ BRL-CAD Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/brlcad-users
