When people ask what I do for a job, 9 times out of ten I
will say “artist” or “I work in the film business”, which quite often gets
mixed responses. Some people say “oh cool, so you meet movie stars?” and others
say “hmm… not a proper job then”.
Truth is my job is a weird one. I say “artist” because it’s
easy, and if people ask further I will explain in more detail. What I actually
do is a wonderful mixture of art and technical practice sat in front of my
computer, which includes mathematics, anatomical structure, physics and
programming. My full job title is:
Crowd Technical Director (within Visual Effects for film)
From this I’ll often get, “so you work with crowds at
festivals?” Not quite lol.
Visual Effects or ‘VFX’ artists are experts in creating
realistic effects on their computers for films, TV and games. Everything from
CGI dragons to explosions to digi-doubles of actors to weather conditions to
well, anything you can imagine really…
My specific job within this industry is to create realistic
crowd scenes within films… think huge battle scenes or hundreds of rats
flooding into a Parisian kitchen:
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iRobot © 20th Century Fox : : : Image © Massive Software
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Ratatouille © to Pixar : : : Image © Massive Software
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A.I Application
The way I create these large scenes with huge amounts of
characters is to build the little guys in a computer environment, and give them
their own intelligence so that they can make their own decision when they’re
“let loose”
The way the characters make their own decisions, is through
a form of logic called “Fuzzy Logic”. Fuzzy
logic deals with reasoning that is approximate rather than exact.
Compared to binary logic (where variables take on the famous 0 (false) or 1
(true) values) fuzzy logic variables may have a truth value that ranges in
degree between 0 and 1, creating as many different potential outcomes as you can possibly
imagine.
Fuzzy logic is applied to many fields, including that of
artificial intelligence, which is why we use it for our large crowd scenes.
Each one of our little guys is thinking for itself :)
This is an example of an agent brain within Massive:
It might look scary but it’s very very logical, and works
similarly to a human brain when decision making. Imagine all of the little
lines are connections in a brain, all coming together to make rational
decisions and behaviour types. For example:
If someone is walking towards me AND they are approaching on
my left = I will turn right to avoid them.
This can then be developed further, so:
If someone is walking towards me over 3 mph AND they are
approaching me at a 45 degree angle on my left = then I must slow down AND turn
right by an angle between 20 and 40 degrees.
And so on and so forth:
If someone is walking towards me above 3 mph AND they
are approaching me at a 45 degree angle on my left = then I must slow down AND
turn right by an angle between 20 and 40 degrees. However if someone is walking
towards me at 3 mph AND they are approaching me at a 45 degree angle on my left
AND they are wearing a pink jumper AND NOT wearing a hat =
then I will turn towards
them, wave and then stop to chat.
You can see how things can get out of control with those
little brain connections ;)
As well as brain development, it’s important to set up
motion trees so that the agents can transition between different actions, do
lot of curve editing, cloth simulation, skeleton building, physics set ups and
anything else that will make our little friends look as realistic as possible.
Example of inverse kinematic curves (used for helping feet stick to
the ground so they don’t slide about and look silly):
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Image © Massive Software |
As a crowd TD I have so far worked on Disney, Marvel, Warner
Brothers and Futurikon films.
To find out more about crowd simulation and the wonderful
piece of software that I use, please visit:
www.massivesoftware.com Without
these guys, none of these incredible crowd scenes in the movies we al love
would be possible.
I hope I’ve explained this reasonably well, if you guys have
any questions or are interested in becoming a crowd simulation artist, drop me
a message :)
Other cool links: