I created this video using Blender. The shape of the tree was made using Inkscape. Video was edited with iMovie.

The Visualization Toolkit (VTK) is an open source graphics toolkit. It is a platform independent graphics engine with parallel rendering support. VTK has an active development community that includes laboratories, institutions and universities from around the world. VTK has several large collaborations between Kitware and national organizations such as Sandia National Labs, Los Alamos, and Livermore National Labs, who are using VTK as the foundation for their large data visualization research efforts. – Wikipedia.org

I have been following the progress of computer graphics since before it was in common use in the movies. I think we are finally at the point where we can mimic with CGI just about anything that you can see in real life. Since about 60 percent of the film is in CG I had a lot of eye candy to soak up. Here are a few CG shots that from Avatar that I thought were particularly well-done.

Jake digs his toes in the dirt. (It may have been done with real feet in real dirt). A bulldozer moves through the dirt and you see the dirt cling to its tracks and fall off the other side as the tracks move around.

Realistic skin is difficult enough to render, but in Avatar you see skin that is wet from rain and sweat. In one shot Jake falls down in some mud and then he attempts to wipe it off his face. Very realistic. There is a shot when he bites a fruit and the juice runs down his chin. There is a shot when Neytiri drinks water from a flower and the water drips off her chin. In another shot Neytiri is putting war paint on Jake’s face. It really looks like viscous paint is being smeared on his skin. His skin and lips respond as if they are really being touched. I don’t know if they used some kind of soft-body collision detection or if someone had to hand animate that. In either case it was well done. During a battle scene Neytiri’s skin is shiny with perspiration, but also bits of dirt and debris stick to the sweat.

I’ve seen other movies where they attempted to animate two CG characters kissing. They got it right in this movie.

Any time a helicopter flew over some foliage the plants whipped about in the prop wash. The clothing and hair on the Na’vi also rippled in the breeze realistically.

A tree falls over in one scene and you see the splintering of the wood. I can’t imagine how that was animated. As the tree falls the air is filled with splinters, dust and leaves. There are many shots where insects buzz about in the background which adds a touch of realism.

CG fire, smoke and water has gotten pretty realistic recently. One especially nice shot is when Jake reaches in a stream to pull out a stick. The water ripples nicely around his hand. There are other shots of realistic waterfalls, water dripping off leaves and waves crashing against rocks along the shore. At one point Jake jumps into a river to escape a predator. The water splashing around looks very convincing and it soaks his shirt and coats his face.

Most of these things have been done before in other movies, but never before have there been so many complex and realistic CG shots in one movie.

After seeing Gollum in The Lord of the Rings and the giant gorilla in Peter Jackson’s King Kong, I began to feel optimistic again. But I had no idea what was in store for me in Avatar. From the moment Jake Sully inhabits his Avatar to the end credits my eyes were glued on the 9 foot tall Na’vi people and their beautiful planet Pandora. Every time the movie cut back to the humans I was a little disappointed. It was as if I was watching the Wizard of Oz that had been intercut with scenes from Kansas. I was filled with so much wonder that I told myself while the movie was still playing that I had to buy the DVD as soon as it was available. The great thing about the Na’vi being computer generated is that the actor’s facial expressions are not hindered by latex prosthetics and colored contact lenses. I didn’t think about the actors having to sit in the makeup chair for two hours every morning before filming started. The people on the screen were the Na’vi. As the actors moved through the jungles of the planet Pandora I didn’t think to myself, “I wonder if this was filmed in Hawaii or Costa Rica” because every twig and leaf was created in a computer specifically for the movie. In essence it was filmed on location in Pandora.

Because every rock, waterfall and living thing on Pandora is so realistic the movie messed with my head. I found myself getting sucked in because I knew that I wasn’t looking at Styrofoam props, matte paintings or people in makeup. The result is a kind of exhilaration I haven’t felt watching any other movie. The Indian director Ram Gopal Varma says it well, “Avatar is by far one of the best films I’ve seen in my life. James Cameron is God. In fact, he’s gone a step ahead of God by building a world that even God couldn’t imagine. After watching Avatar I felt I belong to a primitive filmmaking world.” [from Indiatimes.com]

About Colin Levy
Colin Levy’s Reel (Reel?)
Colin’s latest project: Durian

LuxRender is a new, open-source, free software rendering system for physically correct, unbiased image synthesis. Rendering with LuxRender means simulating the flow of light according to physical equations. This produces realistic, photographic-quality images. – LuxRender.net

As I understand it, an unbiased renderer is one which attempts to simulate the physical properties of light. Biased renderers allow you to create images which would not be possible in the real world. For instance light in a biased renderer travels directly from light sources to objects in their path. Once the light strikes an object it stops there. Any surfaces in the shadows would be perfectly black. In unbiased* renderers the light travels from light sources to the objects in the scene and then continues to bounce around until then energy drops to an insignificant level.

* July 4, 2009, When I originally posted this I wrote biased which is incorrect. Unbiased = close to real world physical light simulation. Biased = fake, less realistic

Low resolution displays are weakest when reproducing curves or lines that do not run perfectly vertical or horizontal. Aliasing is what we call the jagged edges and artifacts that result. One method of reducing the effects of aliasing is decreasing the size of the pixel. A typical computer screen has about 72 pixels per inch (ppi). A display of 300 ppi would be capable of producing smoother images because at that resolution it difficult to distinguish Individual pixels.

Another method is anti-aliasing, the process of smoothing the jaggies by coloring adjacent pixels with an average of the two. As you can see here, black text that has been anti-aliased on a white background has pixels of various shades of gray along the curved portions to give a smoother appearance.