How Doc Ock Got Ready For His Close-Ups in Spider-Man II

Spider-Man still does everything a spider can, but the blockbuster Spider-Man sequel gets maximum mileage out of a new villain, the tentacled Dr. Octopus, known as Doc Ock for short.

The critical task at Sony Pictures Imageworks was creating a digital double that could stand up to Doc Ock’s close-ups. "I knew from the start this would be our biggest challenge because there were a lot of shots where the camera was very close to the digital Doc Ock," says visual effects supervisor Scott Stokdyk.

The studio used motion capture to create facial movements, then considered alternatives for handling the skin. Stokdyk tried a method made possible by the Light Stage, a system for photographically capturing the reflectance field of a human face developed by Paul Debevec and implemented at USC’s Institute of Creative Technology. The images it provides can be used to render the face under arbitrary changes in lighting and viewpoint.

Here’s how it worked: Molina was seated in a chair and surrounded with four film cameras running at 60 frames per second. Above his head was an armature with strobe lights firing at 60 fps that rotated around the chair while the cameras were filming. "At the end of eight seconds, we had 480 images from each camera with different lighting conditions in each frame," says Stokdyk. "We derived the texture as a combination of images and intensity that’s calculated by a RenderMan shader."

The intensity was determined from high dynamic range images of the set shot using a fish-eye lens to create a full 360-degree environment. Those environmental images helped the RenderMan shader determine which of the 480 images of the actor’s face would be used in each shot.

The Doctor’s arms were more straightforward. Puppeteers collaborated with CG artists on the snakelike tentacles that tossed people like rag dolls across a room. Puppets were used for the arms when they directly interacted with the actor – when he lights a cigar, or brushes his hair back. "But when he had to do anything with more than four feet of tentacles, we used the CG arms," says John Dykstra, visual effects designer on the film.

The puppet arms were sent to Gentle Giant, where modelers working in Maya created digital appendages to match, rigging them so the spacing between the vertebrae in each tentacle could subtly change the length of each metallic "arm" and create the appearance of shock waves upon impact. When the character wasn’t entirely CG, Molina was shot traveling through the air on a wire rig and the tentacles were attached later.