You're right, OSG has no built-in capacity to sort a list of Polygons within a single Geometry/Drawable based on distance. This is primarily because there are better solutions available. Putting each Polygon in its own Drawable is a possible solution but would be wasteful of memory if vertices are shared. Probably the most efficient solution would be to render back faces first, then front faces. You could do that with a single custom Drawable, or you could have two references to the same Drawable each with different StateSets: one configured to render back, the other front faces, and in separate RenderBins for ordering. Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com <http://www.skew-matrix.com/> 303 859 9466
Hello to everyone, I am currently working with OSG on a scientific visualization program, I need to display some transparent concave shapes (some isosurfaces), unfortunately I could achieve only partially correct results since I can sort transparent objects but they still appear as if they were "teared". Apparently OSG is able to sort transparent "whole" objects based on their distance from the camera but cannot sort their polygons. A possible solution would be to create a drawable for each polygon and let OSG sort the polygons as if they were objects but probably that's going to be a very slow (and ugly) procedure. Another alternative would be to "manually" sort the polygons of my mesh before every frame which sounds very similar to an hack. The same problem can be seen also by simply visualizing a transparent sphere (disabling back face culling): from some points of view the sphere appears as if it was teared with a sharp saw-tooth-kind pattern, enabling backface culling the problem apparently disappears (since is a convex shape). Isn't there an efficient "out of the box" feature/node in OSG that sorts the polygon of one or more objects based on their distance from the camera? Cheers, Mike
_______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
