On Baby’s Day Out, I had a small in-house previs team to help with the technical aspects of shooting the fairly complex composites we needed to produce. Most of this animation was done on Mac 950s with Ifini-D software — pretty speedy in 1993 terms. In this case we were able to shade and texture our outputs to give them more life. This was the first show in which I played back the previs to mix with the live-action in realtime to check camera angle, speed, etc.

On X-Men, we fully animated the Train Station sequence, the fight on the Statue of Liberty, the X-Jet, the Mystique shots, Senator Kelly’s escape and, of course, Cerebro. The previs helped explain to the director and the rest of the crew what the technique would be. Once the director approves a sequence, I break the sequence into its parts and render the parts as they need to be shot. For instance, with blue or greenscreen shots, I replace previs backgrounds with blue or greenscreens as they will be built on stage, and lay a grid on the screen for size and angle reference. This gives us a check to make sure we don’t have too much or too little screen, and the grips and gaffers know how to rig and light the screens. I also use the previs with the special effects and stunt people to determine the best way to rig and shoot the action, and with the DP to determine lighting and camera issues.

The schematic drawing of the X-Jet gives the production company an early look at the vehicle.

On most shows that I do, the previs is stored in the video assist person’s computer so that it is always accessible on the set for reference as we shoot.

The most powerful aspect of previs is its ability to show what the problems will be with set-ups in difficult locations or with difficult rigging situations. On Clockstoppers, we used previs to determine motion control moves well before we got to the location. This was very important on that show because the motion control had to fit in some very tiny spaces. We modeled the rig, and placed it on the virtual set so that we knew beforehand that everything would fit. We then exported the move to the moco rig from the previs, and used the previs move (usually with small edits) to drive the camera on the set.