[osg-users] Getting the "depth clamped" projection matrix of a CameraNode

[Alan Purvis]

Hi,

CameraNodes unlike SceneViews don't appear to have a getCullVisitor()  
function, I'm guessing they're visited by the same CullVisitor as the  
root SceneView that contains them. Without access to this "root  
SceneView", is it possible to get access to the exact projection  
matrix applied to the contents of a CameraNode with an absolute frame  
of reference (and no projection transforms attached to its children  
other than the one set on itself)?

I have a (heavily) multi-pass scene graph set up doing per fragment  
depth of field with some RTT pre-render passes and rendering textured  
quads to various destinations with shaders attached. One requirement  
of the algorithm I'm working on is access to the projection matrix  
used to render the original "scene texture" by the quad that is used  
to render that scene texture to the frame buffer (or another FBO  
depending), this is required to reverse the non-linear transform  
applied to values in the depth buffer among other things. Simply  
calling getProjectionMatrix() on the CameraNode after it has rendered  
its image returns the original matrix I passed it though, is the  
actual matrix used for rendering retained after culling and drawing  
have completed? If so, then where might I find it? and if not is  
there some callback or something I can use to grab it while it's  
floating around the scenegraph?

Thanks,
Alan