Trombone Integration

Left to right: Raw footage | Direct lighting | Full lighting | View on integrated images | Final result

The footage was filmed in a restaurant and I added pepper corns on the table to have proper tracking marker. For the fill light HDRI, I used the very basic but for me still useful method of photographing a chrome ball with different exposures. Because I added proper lights in 3D for the ceiling lights I reduced the exposure of these in the HDRI.
The trombone is a 1:1 model done by myself, based on a real trombone. Of cause the napkin and silverware had to be recreated as well, to get the reflections on the trombone.
For the caustics I used Renderman's VCM integration and rendered a caustic image from top (luckily a table is flat and doesn't move) and used this image of he caustics as a texture.  This way I had a render time of seconds for the caustic sequence, instead of re-rendering the literally same caustics, which would be way more time consuming.
Removing the pepper corns in comp on a slightly blurry footage was fiddly (these corns which disappear and appear again behind the napkin and fork), but having a pure white tablecloth (and napkin) helped a lot.