Hi Jörg, This type of topic is best discussed on osg-users so that the whole community can chip in. osg-submissions is a just for code submissions themselves rather than general discussion. So could you repost your email to osg-users?
Thanks, Robert. On Sat, Mar 12, 2011 at 2:14 PM, Jörg Bachmann <[email protected]> wrote: > Hi, > > until one week ago, i have writte a small library (C++) to simplify > meshes! today i learned to know about osg (took me ~5 hours to complete > all tutorials) and i really like it. i saw, that there is a LOD class > and i saw this thread: > > http://forum.openscenegraph.org/viewtopic.php?t=3699 > > i think, what he was asking for is not lod itselfes, but for techniques > to simplify meshes, which told me that there are no meshsimplification > algorithms implemented in osg.(? <- 1st/2 question) > > iff that's the case, i'd try to port my meshsimplification lib to a > plugin or something similar, but possibly i'm not familiar enough with > osg, to see where to start. that's why i would ask for some help to > "port" my classes to osg. > > > i implemented a flexible interface to use different (pluggable) > simplification approaches (all based on edge-collapses) and > collapsing-functions (choice of coordinates for vertex of collapsed > edge). so far, i have the following implementations, which produce > really nice results. > > simplification approaches: > - sth. like polychob by s.melax (based on normal errors) > - garland & heckberts quadrics errors (based on geometric errors) > - approach to avoid mesh degeneration (simple math, own idea, only > meaningful in combination with one of the other) > - one approach which simply summarizes them (weighted sum of the above > mentioned / like hoppe) > > collapsing-functions: > - choose midpoint > - choose weighted midpoint (on edge), based on areas of surrounding > triangles > > > nevertheless, the "library" has some benefits: > - own mesh class, to handle simplification (need a lot of cross > referencing lists... list<triangles>, list<edges>, list<verts>) > - triangle handling only > - not sure about licenses of garland & heckbert / melax > > > well. then there is one last question: LOD only hops between levels (of > details). i also wrote a derivative, which interpolates between levels > to not see jumps in graphics. would it be possible to get that working > efficiently and elegant in osg? > > best regards, jörg > > _______________________________________________ > osg-submissions mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
