I'd use OSG for this, although not the rendering portions. You'll need to learn a whole lot about the scenegraph structure, how to traverse it, accumulate tranformations, how to access geometric elements (tris, quads,..), how to access normals, vertexs, colors, front vs back facing, ....
All really fun stuff to learn, but it's going to take time. However, once you know this stuff you'll be able to bang out this type of analysis in no time - I figure I could do it in an hour or two. Search on SmoothingVisitor and TriangleFunctor that should get you started. Brian [EMAIL PROTECTED] wrote: ----- To: osg-users@lists.openscenegraph.org From: "John Wilde" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] Date: 02/28/2008 03:43PM Subject: [osg-users] Extracting visible geometry Hello OSG users: I am wondering what OSG can provide in solving the following problem: Given a scene with on the order of 100s of simple geometry elements (perhaps osg::Box types) and given an (x,y,z) position in that scene, I'd like 1) A list of all polygonal planes that are *visible* from the given point (in all directions). For example, if the scene consisted of a single Box (a building), and the given point was near a corner at the base of that box, I'd like to know the two polygons describing the two visible faces of the box (sides of the building). If a portion of the box was occluded (by other geometry in the scene), I'd like the polygon that describes only the visible portion. I am basically interested in knowing the surface area of all the visible geometry in the scene. 2) The distance from the given point to a point on the visible surface. 3) Color information associated with each visible surface plane. Could someone suggest parts of the OSG API I should learn in order to solve this problem? Do you think OSG is the right tool for this sort of analysis? Thanks in advance for your help. John _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- This is a PRIVATE message. If you are not the intended recipient, please delete without copying and kindly advise us by e-mail of the mistake in delivery. NOTE: Regardless of content, this e-mail shall not operate to bind CSC to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
