Technical Paper:
Bull Rigging

GP2 of Brazil was in need of a realistic bull that could be substituted into some shots instead of using a real bull. The reason for this is because the bull had to come very close to cameras and actors.

The mesh was modeled in Brazil and sent to PEN Productions for rigging.

Movies:
bullRun.mov
bullRunRig.mov
bullShake.mov

The bull eventualy was covered in fur for some shots and was rendered in V Ray.

Animation on the bull was done by hand as getting a bull into a motion capture suite was out of the question.


The control set for the character rig was set to the clients specifications with an FK driven spine, automated double IK legs with manual over rides and dynamic simulations built in.

The main joints of the body can be seen here as well as the driving joints for the neck, ribs, tail and privates.

Real time dynamic solutions were used to drive the fleshy areas around the neck and head as well as the privates. the ribs also had a dynamic bounce to them as well.

Since real time dynamics can over shoot their range a scripted function curve solution was added to track the velocity of the bull and ramp the dymanics up and down depending on the speed.


Painted soft selection areas allowed for real time dynamics to also be driven on the geometry, this resulted in realistic motion in the most fleshy parts of the character.