Right class today we are going to discuss Global
Illumination. What is that? Well let�s start with a definition.
"Images of the real world are formed by visible
light being scattered by surfaces and volumes. The goal of global illumination
methods is to simulate the path of light in an environment through the image
plane in order to compute realistic images".
These two sentences come from the paper �A Basic
Guide to Global Illumination� delivered at Siggraph 98 by David Banks, Holly
Rushmeier and Peter Shirley.
But what does this mean to us? Basically it is a
way to create really realistic 3D computer generated scenes. This sounds really
dry and boring. Well before I go any further let me show you a couple of sites.
http://www.3dluvr.com/pepeland/
http://www.3dluvr.com/marcosss/morearni/
http://www.cs.kuleuven.ac.be/cwis/research/graphics/CGRG.FUN/esscher.shtml
The first time I saw these pictures, I couldn�t
believe they were really computer generated 3D images. I would say, �Naaa, the
clay dude is CG, but everything else is filmed�. Well I was shocked. These
models really looked like they were real. Like they were actually made out of
clay. The way the light fell on the objects was so subtle and convincing. Just
to save some of my sanity and ego I showed these to friends in and out of the
industry to observe their opinions. The same disbelief fell upon them. These
pictures are the result of Global Illumination rendering. Put simply, it is a
process of calculating not only how the light that is emitted from light
sources bounces off the objects in the scene, but also how the light is
indirectly bounced off the objects in the scene. It is however more
complicated, so if you want some technical explanations go to these sites.
http://www.integra.co.jp/eng/papers/cmgia/
http://www.umlaut.fr/XSI/FinalGathering.html
The pictures that comes from the first two web
sites come from a renderer code named �Arnold�. This magic piece of software
was created by Marcos Fajardo from Malaga, Spain, who is known as somewhat of a
guru in renderers. Using a rather cute character to demonstrate the renderer,
Marcos has been pushing the boundaries in creating a commercially viable global
illumination and radiosity renderer. Over a year ago he started collaborating
with pmG. This has resulted in �Arnold� being released in a product called
messiah:render. Global Illumination renders are available elsewhere. All the
major 3D animation products are now offering this as a new feature.
http://www.projectmessiah.com/
www.flay.com
It also got me thinking about where this is all
going. I truly see a future where computer generated imagery is created in real
time and is completely realistic. It will be like using a stills or video
camera, filming your synthetic scene like it was real. You could even go so far
as to say that directing your synthetic actors could be done the same way it is
done in real life. Just using the words �Action�.
Apart from telling you all about some great new
eye candy, I also wanted to tell you a more personal story, which was prompted
from the pictures and movies available in the above web sites. It is all about
sharing the magic. We all work in a field that is rather technical, and as a
result our friends and family tend to listen to our babblings with absent
acceptance. I however have been blessed with a wonderful wife who is fascinated
with what I do. She observes and learns anything to do with animation and
special effects. Actually I think she is a keener learner and more intelligent than
me, but don�t tell her, else I�ll never hear the end of it. The upshot of all
of this is that we will be sitting in the lounge waiting for �Chicago Hope� or
�Trial and Retribution� and Rhonda (my wife) will pipe up and say, � They
didn�t key that presenter well did they. I mean there is an edge to her and the
black levels are completely different to the background �. Or we will be
watching �Gladiator� and she will lean over to me and whisper, � that scene had
some great compositing�. I love it. It is so special to share my passion with
someone whom I have a passion for. Going to the movies to see a FX movie like
�MI 2� is a real talking point for Rhonda and I. I get so much more out of my
career when I share it with people, especially my wife. Maybe this is all new
to me cause I am newly married, but irrespective it is something special. So go
the extra mile and share the magic.
Queries and comments to : [email protected]
