Hi Richard, You could play multi-pass tricks like done in the osgdepthpartion example, or just manage the visible distance so that the furthest distance is never too far away. For instance a common trick is to use Fog to make far objects fade away until eventually nothing beyond a certain distance can be seen - so you simply cull it and this pull in the far plane. The skydome could also be computed dynamically to just fits the size of the scene required for that frame instead of the whole model.
Robert. On Dec 17, 2007 1:17 PM, Richard S. Wright Jr. <[EMAIL PROTECTED]> wrote: > I'm working on my first OSG project (so be gentle ;-) I'm using OSG 2.2 on > OS X (Leopard). > > I have a terrain in a .osga file, a skydome, and some .3ds models. > Everything loads fine, and I have a flight sequence working that takes off > and lands on an aircraft carrier. > > There are lots of samples that made this part pretty easy to figure out > (just load and move objects around). I'm a little lost however as to how OSG > is handling the near and far clipping planes, and object scale. Actually, > OSG seems to be monkeying with these settings in a manner that is probably a > nice feature once I understand how to best make use of it. > > The terrain is really big, the skybox is really big, and the models are > really small in comparison. OSG seems to recomputing the near and far > clipping planes depending on the objects in view. For example, on the deck > of the carrier, all is well. If I turn so that the terrain is also in view > (off in the distance), the near clipping plane seems to be changed and parts > of the carrier disappear (the same happens with the large skydome...) > apparently to accommodate the display of the much larger model that is now > in view. > > I did find an old message that says this: > > > Camera->setComputeNearFarMode(osgUtil::CullVisitor::DO_NOT_COMPUTE_NEAR_FAR); > > prevents this... however, then I need a giant frustum to hold everything and > we all know what a bucket of z-fighting joy that brings. It is not clear to > me how to arrange these objects correctly to make this "rescaling" of the > scenes objects work correctly. Currently, the terrain database, the skydome, > and the ship models are all hanging off the root of the scene graph with > just a transform that scales, translates and rotates them as necessary. > > Is there a 'standardized' technique for this (it can't be that unusual), > none of the example programs seem to have this kind of configuration. > > Richard > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
