Hi Jose,
I'm working with a light (spotlight) concretely. I would like that this light
didn't go through walls. How can I obtain this effect?
In real life, the fact that a light doesn't go trough walls is a
consequence of the fact that solid objects block the light (i.e. cast
shadows). The "darkness" behind a wall is the wall's shadow.
Unfortunately the default real-time graphics pipeline doesn't render
shadows natively as it's not a raytracing engine (in which shadows come
naturally from the algorithm of tracing rays and finding intersections
in the scene). In real-time graphics, we must "cheat" shadows.
Have a look at the osgShadow nodekit that's part of OSG, in particular
osgShadow::StandardShadowMap and
osgShadow::LightSpacePerspectiveShadowMap, and the osgshadow example
that ships with OSG's source code. These use a technique called Shadow
Mapping which is a good way to render shadows, but has a few gotchas.
I recommend you do a bit of reading about these techniques before you
use them so you know what to expect. Google can help you find some
on-line articles about real-time rendering of shadows and shadow mapping
in particular. I also recommend "Real-Time Rendering" by Tomas
Akenine-Moller et al, and Computer Graphics: Principles and Practice by
Foley, Van Dam et al. if you want good books about those kinds of things.
Hope this helps,
J-S
--
______________________________________________________
Jean-Sebastien Guay jean-sebastien.g...@cm-labs.com
http://www.cm-labs.com/
http://whitestar02.webhop.org/
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
