Here I have a couple of images from a lighting and rendering experiment using camera projection to insert 3D objects into a photograph.
My goal with this was to try and make something unbelievable look believable. We know that giant robots don't exist yet, but through creative use of camera projection (the original photograph of the scene is projected onto 3D geometry that I designed to mimic the layout of the ground and buildings), HDR lighting, raytrace shadows, depth of field, and ambient occlusion, you get a pretty interesting result. Can you tell that the windmills on top of the building are fake too?
This served a double purpose; I created the sword model for a project that some friends were working on, and I also used it as another camera projection project for one of my college classes. Cloth simulation as an added bonus.