HI Jon thanks for you response!
On Nov 13, 9:31 pm, Jon Bradley <[EMAIL PROTECTED]> wrote: > On Nov 13, 2008, at 1:00 AM, Bright wrote: > > > CSG modeling widely using on cad/cam ,btw google sketchup seems to > > support this way .away3d have some primitive model ,Some way can do > > csg calculate(boolean) and get complex model ,pls give some > > advice,thks > > CSG used to be widely used. It's now only really used in CAD/CAM > applications that use implicit surface modeling and bounding volumes. > CSG is not very good for polygon set operations - because CSG trees > usually use mathematical representations of surfaces. If you wanted > to do NURBS, or higher order surface set operations, then CSG would > be the way to go. > > There's nothing out there in the public for 3d polygon set operations > (in Flash). Tim of PV3D did do some operations in his FloorPlanner > application. FloorPlanner uses a home grown BSP algorithm for the > operations. > > For general 3d polygon clipping, implement a BSP tree algorithm and > do polygon clipping within the resulting BSP tree(s). There's a lot > of information online on merging BSP trees to peform union/ > subtraction/intersection. XOR/AND and the other operations are quite > a bit trickier. > > SketchUp uses BSP trees, as do most 3d applications. > > Good luck, > > Jon
