Hybrid renderer

[vchizhov]

Upon finalizing a rasterizer that matches the ray-tracer, a hybrid mode may be added. The result of the primary rays will be a product of the rasterizer, while any subsequent bounces will be from the ray-tracer. This would require the rasterizer to generate a buffer of positions + normals + materials at each pixel, from which subsequent rays may be generated. A restriction in that case will be the sampling of the primary rays - in each frame the samples for those should be slightly jittered if possible. There is also a concern regarding AA, where a higher resolution image should be fed to the raytracer if actual AA is desired.