Little history on Digital Lighting Effects

Another amazing feat from production teams at Pixar Animation Studios, Emeryville, California, “made possible by modern technology (William*)”. With processors and memory available in such large quantities more computing can be done in less time, with time being money, and films having a limited budget it means higher quality films can be made at lower special effects costs.

Simply put: How?

The film WALL·E uses a derivative of the Ray Tracing Technique, light rays are projected perpendicular to the viewpoint plane into the digital environment and reflected off surfaces until a set number of bounces or they reach a light source. This creates a very realistic looking shot, with the realism being proportional to the number of reflections, 1 bounce casts shadows but doesn’t produce any ambiance, 3 looks only just plausible but will be too dark, 8 would be acceptable for daytime television and a full 16 or more are used in motion pictures.

As you can imagine each bounce has to be remembered, the colour information of its reflecting surface(s) and the distance between each one until it matches a finishing condition, this has to be done for each pixel. A rough idea of film resolution is 2048 by 1152, that’s 2,359,296 light rays (2.4 MegaPixels) every 1/24 of a second. An awful lot to remember for just one frame of 129600 in a 90 minute feature.

Is there a simpler way?

There are many other ways, each with pros and cons, my particular favourite, for sentimental reasons, is Ray Casting, the technique used extensively in the film Tron (1982).

Ray Casting functions in a similar way to Ray tracing except there are no bounces once reaching a surface, colour and shading is faked. With less information to remember the process is a lot quicker but also has more inaccuracies. If the shading and colouring isn’t done proficiently then the entire shot looks fake.

Further Advances

There you have it, the basics in how light and shadows are produced digitally. Mathematical equations work out the path a real light ray might take, complicated stuff made possible by the advances in technology. Luckily Pixar aim to create one frame (1/24 second) to be rendered in 3 minutes, making a whole film take a year, so its safe to say we’re a long way off being able to create photorealistic digital environments in realtime. When that happens I would worry, if we could create a near perfect environment in a simulator and you went into that simulator how would you know if you really left?

WALL·E

Such a loving little film about an endearing robot. Whenever I’ve been in the cinema over the last month or so I’ve heard people saying “Have they remade Short Circuit?” Obviously not but there are some similarities. Back then they used Johnny as a promotional tool, but there was only one because it was sooooo expensive to make, with most of the budget going to the Visual Futurist, Syd Mead, who designed him.

How things have changed, now there are many of the things.

One of my Favourites clips

Keeping with the jovial attitude of the majority of their films the Animators often place a lot of ‘in jokes’ throughout their features Jim Hill lists most, if not all, the visual jokes Pixar employees have included in their final products. Enjoy.

Name that Polyhedron!

For recent design project I spent the better part of a day trying to find out the name of a 72 faced shape. Finding the schema for naming a 2 dimensional shape, also known as a polygon, by its number of faces was easy; wikipedia had a brief naming table. Finding a similar table for a 3 dimensional shape, or polyhedron, was a lot harder (I actually had to use a book!) but very obvious when I found it.

Polyhedron & Polygon Naming Conventions

Having a table of naming information is useful but learning the rules behind how they are named makes things much easier to remember so I’ve summed up my observations.

  1. Both regular poly shapes are named from largest number to smallest, that is hundreds, tens, units
  2. Polygons can use the ‘kai’ conjunctive between Tens and Units .e.g. tetracontakaidigon and tetracontadigon are both valid for a 42 faced shape
  3. Polyhedrons end in ‘hedron’.
  4. Polygons end in ‘gon’.

For numbers greater than the table I’ve provided and the one available on wikipedia you multiply each digit by its base and call it as such so 4,000 faces becomes 4 × 1000 and called tetra × chilia + gon, 300 faces becomes 3 × 100 called tri × hecto + gon.

Table you can use from left to right for naming shaped 1-100
Tens and Units final suffix
10 deca- 1 -hena- -gon
20 icosi- -kai- 2 -di-
30 triaconta- 3 -tri-
40 tetraconta- 4 -tetra-
50 pentaconta- 5 -penta-
60 hexaconta- 6 -hexa-
70 heptaconta- 7 -hepta-
80 octaconta- 8 -octa-
90 enneaconta- 9 -ennea-
100 hecto- 0

For numbers great than one hundred you can use this base numbers.

Name Value
100 hecto
1,000 chilia
10,000 myria

Film Review: Superman Returns – The IMAX Experience

On the doomed planet Krypton, a wise scientist placed his infant son into a spacecraft and launched him to Earth.

Raised by a kind farmer and his wife, the boy grew up to become our greatest protector… Superman.

But when astronomers discovered the distant remains of his home world, Superman Disappeared.

This was my second viewing of this slice of cinematic history, I wasn’t particularly impressed with the 3D effects though, either it was the glasses being bent out of shape, just plain ineffective or my position in the theatre but I really didn’t feel part of the film. Falling with the plane as Superman tries to correct it’s tail spin was completely wasted on me and it all as a bit of a blur.

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