StevenThe 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 makingholes 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 hadread elsewhere, I had been given to believe "everybody" did CSG. When Iencountered scene graph packages a couple years ago, I was surprised to findthat they don't do this "out of the box". Now that I have a betterappreciation for the magnitude of the challenge as well as the limitations of CSG, I am less surprised. Just contemplating the notion of generic code forhandling 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 scenerotation was jumpy, suggesting it requires a lot of processing. Perhaps thatcan 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 shownhere: http://www.kolumbus.fi/totuus/img/wtc-wall.jpgThere are literally thousands of these exterior panels. Depending on LOD, Iwant 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 thegeometry 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 forcesinvolved.I therefore want my geometric model to be as faithful to the physical realityas 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 savesthings 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
steelhole.dw
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