Hi Torben, On Mon, Jul 18, 2011 at 2:23 PM, Torben Dannhauer <[email protected]> wrote: > Hmm, maybe we talk at cross-purposes: > > osgSim::HeightAboveTerrain provides already a convenience Method for HAT > calculations: > > Code: > > static double computeHeightAboveTerrain(osg::Node* scene, const osg::Vec3d& > point, osg::Node::NodeMask traversalMask=0xffffffff); >
Ahh... forgot completely about this method. This convinience function is a bit too convinient really - encourages inefficient usage as it'll be creating the DatabaseCacheReadCallback on every invocation and will load external files then dispose of the associated subgraphs as soon as the function exits. > I can't really follow you regarding the computation effort or paging > performance, because the HOT calculation is no extra step, it is a by-product > of your HAT calculation. If you have a geocentric model then you are doing an extra computation. > I agree that the HAT-class may not be not the best place for HOT > calculations. ;) It's not a general purpose intersection class, is a very specific interseciton class. It's also pretty tiny, and easy to replace with more user specific code. > Meanwhile I'll add these functions to the osgVisual utils to provide the > users of my department a simple to use interface to query hat / hot. All the osgSim interseciton classes are just wrappers on top of the core osgUtil::IntersectionVisitor functionality, if these classes don't fit the bill then it should be straight forward to build your own similar implementations that do exactly what you require. Robert. _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
