For some reason everything seems to be having a problem since I rebuilt OSG from cvs. I haven't had time to investigate.
On Wednesday 25 October 2006 03:18, Geoff Michel wrote: > Steven > > The tesselated scene rotation is not jumpy on my machine (2.6GHz Pentium + > nVidia 5200 card - 75 Hz rock-like). The tesselation is only done once, and > again whenever the N key is pressed to retesselate. > > Try saving the OSG format file - this does not have any osgTesselation > components, just the pure polygons so there is no effect of the tesselation > if you load the osg output (except that tesselating something which looks > simple can result in large numbers of triangles). > > Try the attached .dw file (which I created this morning with 2 rectangular > holes in a plate) in osgviewer - the format is very simple so you should be > able to generate your own. The holes can be any polygonal shape that is > confined to one face of the parent shape. (Of course you need to compile > the .dw plugin). > > It is not full CSG of course but simple holes sounds like all you need. You > could adapt the parts of the dw loader that cut holes in objects if you > wish! > > Geoff > > > ----- Original Message ----- > From: "Steven T. Hatton" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Wednesday, October 25, 2006 12:59 AM > Subject: Re: [osg-users] Drilling Holes in Beams? > > > Thanks to everybody for the feedback. For now I think I'm going to be > > making > > holes by hand. That is, I will create the surface using multiple quads > > patched together so that the area surrounding the hole is covered with a > > separate patch. > > > > I tried my hand at POVRay many rears ago. Along with a few statements I > > had > > read elsewhere, I had been given to believe "everybody" did CSG. When I > > encountered scene graph packages a couple years ago, I was surprised to > > find > > that they don't do this "out of the box". Now that I have a better > > appreciation for the magnitude of the challenge as well as the > > limitations of > > CSG, I am less surprised. Just contemplating the notion of generic code > > for > > handling solids of arbitrary shape with holes is mind boggling. > > > > The tesselation code in the OSG example appears to provide a potential > > solution for some situations. When I ran the examples, the animated scene > > rotation was jumpy, suggesting it requires a lot of processing. Perhaps > > that > > can be done once and "cached"? > > > > Here's an example of the kind of problem I am currently dealing with. I > > want > > to model a building constructed of column and spandrel assemblies, as > > shown > > here: > > > > http://www.kolumbus.fi/totuus/img/wtc-wall.jpg > > > > There are literally thousands of these exterior panels. Depending on > > LOD, I > > want to be able to zoom in on any given detail and have it depicted with > > sufficient accuracy and precision to accurately represent the design and > > implementation of the structure. > > > > Though it is no an immediate goal, I would like the be able to modify the > > geometry of one of these assemblies (for example if it happens to be > > thrown > > 700 feet due to some catastrophic event, and becomes deformed by the > > forces > > involved. > > > > I therefore want my geometric model to be as faithful to the physical > > reality > > as is possible (whatever that means). > > > > On Tuesday 24 October 2006 18:02, Geoff Michel wrote: > >> or you could use the osgTesselator to make holes. See the tesselator > >> example. The samples have lots of holes in. > >> > >> Or you can use the .dw format and the Design workbench modeller which > >> saves > >> things with holes in. The "flat plank of steel" need not be flat in DW. > >> I have examples with hundreds of of holes in. > >> > >> (www.artifice.com design workshop lite will do it) > >> > >> NB Someone has used my email- only used for OSG stuff- to send me > >> details on a 'performance' enhancing drug. Dont do that. > >> > >> G > > > > _______________________________________________ > > osg-users mailing list > > [email protected] > > http://openscenegraph.net/mailman/listinfo/osg-users > > http://www.openscenegraph.org/ > > -- > > This email has been verified as Virus free > > Virus Protection and more available at http://www.plus.net _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
