The challenge of creating the digital Iron Man suit included interpenetration and range of motion. The solution had to satisfy the need for appearance of realism while retaining necessary range of motion.

Favreau was also intent that the flying “feel real.” For this task, Nelson motion captured stunt flyers in a wind tunnel to get the proper nuanced motion that Iron Man’s flying style would require. Some of PLF's early tests consisted of putting the MoCap onto their previs version of Iron Man. The results were very encouraging, Seki suggests. This Mocap provided the basic reference from which ILM keyframed their flying animation. The use of Mocap underlined the need to develop a system to incorporate motion capture, but still be able to add keyframe before or after it. Friedman developed a character marionette system that allowed any number of rigs to be used for any one character. The user could then take the character and blend the geometry of a fully weighted character onto any of the rigs (MoCap or keyframe) in the scene at any given time. PLF chose to use this system as well as reference models in Maya since they knew that the character rigs and models would be modified as the job progressed and they acquired new information. "This ability provided a solid base for us to be flexible with vendors and the needs of production," Seki adds. "We could easily swap out the model we made for the Stan Winston suit model, then the ILM one without losing our animation. In addition, as the need arose, Friedman developed the 'advanced MoCap rig' that allowed our artist to keyframe directly on top of the MoCap data to modify it 'on the fly.'

"I initially led the previs effort on First Flight with the Mark II while PLF Lead Kyle Robinson took the reins on the Dogfight. We then split the team between the Escape and Gulmira. Mary Manning and Robinson tag teamed the lead for the Escape while I focused on Gulmira. For these sequences, we tried to get as much staging information from Stunt Coordinator Tommy Harper as we could. In addition, we were allotted valuable time with Cinematographer Matthew Libatique [Inside Man, Requiem for a Dream]. We would try and gleam anything we could regarding his style, lensing and shot selection. His films were 'required viewing' for our artists.