Implementation of screen space ambient occlusion (ssao) using OpenSceneGraph (OSG).
The application window consists of 3 views. Two OSG views on the left and center, and a panel to adjust the screen space ambient occlusion parameters on the right.
The left-most OSG view is rendered with an OSGWidget which derives from the legacy QOGLWidget. This properly displays ssao and is enabled for SSAO at application startup.
The center OSG view is rendered with an Osg3dSSAOView which derives from a Osg3dViewWithCamera which in turn derives from the new QOpenGLWidget. This QT widget renders GL into a texture which Qt then composites into the application window. This does not properly render the scene.
Inspection of the existing SSAO implementation shows that it does all the work in PRE- and POST- render passes. This makes the primary render traversal of no value. Ideally, SSAO would render as PRE- render passes and the primary render traversal would produce the final output. This would likely solve the problem with using QOpenGLWidget as well.
