Hi Justo,
Take a look to the Variante Shadow Map algorithm<http://developer.nvidia.com/node/165> to apply shadow on the scene. Instead of use default OpenGL ShadowMap comparaison technique, this algorithm provide a different way to capture and apply shadow. This technique take more resource but with a better result. HTH David Callu 2011/8/25 Robert Osfield <[email protected]> > Hi Justo, > > Surfaces that are parallel to the light source will be subject to > numerical aliasing issues that will mean that either the fragment is > inside or outside that shadow map. You can't avoid these aliasing > issues completely but if the vertex and fragment shaders are set up > correctly then the parallel surfaces should in theory have the same > ambient lighting regardless of being in the shadow or not so you > shouldn't see the aliasing artifact. > > I have just developed a new shadow technique that you'll find checked > into svn/trunk, look for the ViewDependentShadowMap, use the --vdsm > option in osgshadow example. All going well this will replace the > collection of other shadow techniques. I would recommend testing > against this new technique. > > Robert. > > On Thu, Aug 25, 2011 at 7:12 PM, Justo Ureña <[email protected]> wrote: > > Hi, > > > > I´m testing diferent shadows techniques for my scene, and after some > adjusts, I got them working fine... Except for very big aliasing that > appears in some surfaces that are parallel to the light direction. It > happens in all the shadow maps techniques (ShadowMap, StandardShadowMap, > LISPSM)... and I´ve tried all the things that I could imagine to get rid of > them without success... Please, anyone can help me with that? > > > > From my investigation I got that the problem is that the depth map > calculated by the shadow camera does not fit exactly with the curved shape > in the scene. In the attachment you can see a render of the scene (that only > includes the cessna and a vertical directional light that produces the > shadow) coloured with the depth map. As you can see, in the laterals of the > cessna appear these withe stiches that means that the depth calculated in > these texels of the map is infinite, what is obviously wrong. There is any > way to avoid this annoying effect? > > > > Thank you very much! > > > > Cheers, > > Justo > > > > ------------------ > > Read this topic online here: > > http://forum.openscenegraph.org/viewtopic.php?p=42241#42241 > > > > > > > > > > _______________________________________________ > > osg-users mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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