ceb97fe230
This version adds: - an encapsulation of the entire Depth Peeling procedure into a class (not currently a scene graph node) for easier integration in other projects. - compositing with opaque (solid) geometry is possible and the opaque model is only rendered once. This needs to performs some depth buffer blitting between FBOs. - mix and match with GLSL shaders in the transparent objects is possible, as demonstrated with a 3D heat map intersecting an opaque truck model. Some Drawbacks: - the display framebuffer does not receive any depth information from the compositing camera. This could be fixed by compositing with a GLSL shader and writing to FragDepth." From Robert Osfield, ported the code to work under Linux and without the automatic ref_ptr to C* conversion.