This meant getting the surface normals to work so the specular highlights would work in lighting. When you have something that is highly reflective and rendered in S-3D, the left and right eye highlight location could be very different, causing two highlights instead of one. Though this occurs in nature, in real life our perception tends to be more forgiving. “We don’t tend to focus on those reflections and identify what is seen in the reflections,” explained Ramasubramanian, “but in our case, B.O.B. is big main character and you are supposed to look at him. You are trying to make sense of what’s being reflected on him. Even though it’s realistic to have the left and right eye different, we couldn’t let that happen, we had to have more control over the reflections. Also, if the surface normals changed quickly around high frequency areas such as near his eyes or the folds on the bottoms of his feet, light would reflect off those surfaces.”
The first step in solving this problem was to render the highlights for both eyes from the same camera position. “The reflection would look like it was on the surface, like a texture map, but they needed to have some depth to them. What we did is use the interoccular distance to bring the two eyes closer together only for the reflection and refraction passes, with mostly no difference in the left and right.”
When it Gels
DreamWorks will be releasing Monsters vs. Aliens on every S-3D system that is available, with multiple deliveries for the different formats, taking into account the eyes’ physical abilities to take in certain amounts of depth. “What we are designing for,” says McNally “is screen size rather than the individual system. As the screen gets bigger, the scale of the depth increases. You can look at something on a monitor and feel like its very flat or shallow then you see it on the IMAX and it’s incredibly deep because the scale has gone up with the screen size.
“We are projecting on screens from 35, 40 feet to the biggest IMAX, over 100 feet. It’s important, when you are making Stereo movies, that you test on those public screens and not set your depth on a small monitor.”
Fitting for a character that went from a small project to one that took a task force and a dedicated Character TD 94 weeks to complete!