Donʼt make me angry
Hans Rijpkema*
Matt Derksen†
Dante Quintana‡
Rhythm and Hues Studios
1. Introduction
When in the 70’s television series Dr. Banner changed into the
Hulk, the transformation was shown through a quick montage of
ripping clothes and close ups. The movie “The Incredible Hulk”
however contains a sequence that shows the entire transformation
process slowly and without any gaps in the series of events that
changes the human sized Bruce Banner into the monster sized
Incredible Hulk. This presentation discusses the methods used to
non-uniformly transition between two different characters with
different topologies, proportions and sizes.
2. Rigging
The animator is presented with a single transformation rig which
drives a full set of Bruce Banner deformations and a full set of
Hulk deformations. The rig is essentially a rig for Banner which
allows the bones to be stretched to Hulk proportions, but
independently of muscle mass. The translation of the bones drive
muscle deformations and a number of blend shapes to generate an
intermediate deforming skin. The final skin then slides and
relaxes over the deforming skin.
In order to incorporate Hulk deformations a full Hulk rig with its
original proportions is retargeted on the fly to the Banner
animation in the background. All muscle firings, tendon motion,
etc. are calculated for this hero Hulk rig. An inverse retarget then
creates a non uniformly scaled down Hulk at the current Banner
size and proportions. The differences between the full size and
scaled down Hulk are analyzed and then applied to the Banner
skin deformations.
3. Animation
and how each individual part of the body transforms.
Theoretically a 6 feet Bruce Banner can first transform to a Hulk
shape at the same size and then be scaled up to the final 9 feet size
or it can transform first to a super sized 9 feet Banner and then
morph into the final Hulk shape. Every body part can be animated
to take any path in between these two extremes. Interactive
feedback, while still being able to see the final deformation result
so that the animator can adapt to the changing sizes of the
individual limbs and body parts, is essential.
4. Lighting
Look development was done on different stages of both the Bruce
Banner character and the Hulk character. For each look a multi
layered set of textures and displacement maps was created. They
include maps for relaxed, flexed and emaciated Banner as well as
relaxed and flexed Hulk. The Banner look development had to
match the actor very closely since the sequence starts out with a
live action Banner which then slowly changes into a full CG
version. Based on the animation, the rig then generates a large
number of animated lighting properties in the form of point
attributes on the skin geometry. These attributes can be used to
locally select between mixes of these different looks as well as
control color shifts and large and small vein growth. The
rendering generates multiple mattes and image layers which then
can be manipulated further and more precise in the 2D
compositing stage.
5. Conclusion
A versatile rig presented animators with a relatively
straightforward yet powerful set of controls to manage a complex
nonlinear transformation sequence while generating many
animated lighting properties at the same time.
There are four main sets of attributes that drive the
transformation: bone size, muscle growth, muscle striation and
Hulk progression. The animator can control the timing of when
© Marvel / Universal 2008
* [email protected]
† [email protected]
‡ [email protected]
© Marvel / Universal 2008
Copyright is held by the author / owner(s).
SIGGRAPH 2008, Los Angeles, California, August 11–15, 2008.
ISBN 978-1-60558-466-9/08/0008