From Joran Jessurun, fix to let the Viewer::computeNearFarPoints

function work correctly when used with multiple camera's on one render
surface.

src/osgProducer/Viewer.cpp

@@ -853,6 +853,9 @@ bool Viewer::computeNearFarPoints(float x,float y,unsigned int cameraNum,osg::Ve
     float pixel_x,pixel_y;
     if (computePixelCoords(x,y,cameraNum,pixel_x,pixel_y))
     {
+        pixel_x-=sv->getViewport()->x();
+        pixel_y-=sv->getViewport()->y();
+
         return sv->projectWindowXYIntoObject((int)(pixel_x+0.5f),(int)(pixel_y+0.5f),near_point,far_point);
     }
     return false;