Lately I’ve been playing around a lot with 3D Motion Tracking, and instead of relying on footage that happened to be floating around, I decided to shoot my own background plate and have some fun. I also got a really cheap gazing ball that I wanted to use for some HDRI Spherical Panoramas. This is the result:
Shooting: Chose a nice sunny day with some good hard shadows, and brought the gazing ball and a grey ball out. Shot my background plate at a low ISO and high shutter speed (thus preventing blurring and artifacting). Immediately after I mounted (rather hastily) the gazing ball to where my CG object would be , and shot it in 5 bracketed exposures. Soon after, shot the grey ball.
Post: Processed the RAW photos of the gazing ball to 14-bit TIFS, imported into Photomatix to unwrap and make a 32-bit HDR file. Brought unwrapped HDR into Photoshop and Clone Masked myself and the base out, tried to fix any pinching and warping (I breezed through it knowing reflections weren’t going to be crucial). Once that was done, used Boujou for 3D Motion Tracking, and imported the track onto C4D.
CG: Imported footage as a background object. Then transferred a ground plane and a sphere primitive to the reference markers from Boujou to establish scene scale and orientation. Made a Sky element and loaded the HDR image, adjusted the orientation to match the background plate. Enabled GI and got decent, but soft results. Added a point light with some (but not much) falloff and positioned it around the scene, using the grey ball photograph as a reference for light diffusion. Then made a shader that used Subsurface Scattering to really push light absorption, and then a slightly blurred reflection to sell the object in the scene). Finally, simulated Soft Rigid Body Dynamics (but cheating for speediness sake, using the Clothilde – the Luxx way). Originally I wanted to simulate a rain of rubber duckies falling, but Mograph didn’t like 2000+ duckies and RealFlow simulation was taking more time than shooting and post combined!
In any case, that was some good old fashioned fun.