Ask a Pixar Scientist

How do Pixar artists and animators overcome art blocks?
— Mehrshada

In our discussions we've had with Pixar employees, there really isn't a way to avoid art blocks (much like writers block). The key is to keep focus. You may have times you have to walk away - there may be a time you have to explore a new area of art to crack open your field again. Keep pushing and creating.
— T. J. Wolsos; Khan Academy

How long did it take you guys to make inside out?
— Chris

It usually takes about four years from start to finish. The first two years are spent in figuring out the story, characters, and design, and the last two years are spent in actually animating and rendering the film.
— Kitt Hirasaki; Khan Academy

I was able to check out The science behind Pixar, and it was amazing. The only thing that I was hoping to see in the rigging section is making the characters walk. I'm going to take the exibit's advice and try to use a rig for my character. But I want to ask this while I do this. How long did it take to make a human character walk and what helped you to make them walk?
— Floyd

We animate a human walk by walking ourselves, finding key poses and using the computer to capture the pose using our animation software. A key pose might be when the foot contacts the ground, is fully planted or lifts off. Tweening then captures the in-between motion. This can be done in a day. The hard part is giving the walk attitude. That is acting and can take much longer depending on what performance we are trying to capture. Linguini, from Ratatouille, was particularly fun to do walks as he was so “animated".
— Brian Green; Lead Technical Trainer + Content Specialist, Pixar

Wow! You think its all just you draw it even painting has math. Why do they use math and not just draw it?
— Daisy

If they want to show millions of blades of grass, and want to make them to move realistically in response to wind or horses running past, then it's less work to do it this way.
— Peter Collingridge; Khan Academy

When animators draw, say, a field of grass, do they need to draw each blade individually (so they have different lengths, widths, etc.) or do they have a faster way to create the blades? Could they use object oriented programming (or something of the likes), with a random height and width for the grass?
— Katie

Yes, you're right. They will have tool for generating whole fields of grass with slightly different angles, lengths, colours etc. There is an simple example in the next program, where you animate one blade of grass and it is replicated on a small grid of grass. In the real Pixar program it will be a lot more complex and create a more realistic effect. Also the movement of the grass is likely to be simulated rather than directly animated. It's quite very they use object oriented programming to store the different blades of grass.
— Peter Collingridge; Khan Academy

Do you ever use Tweening (turning separate body parts) in your animations?
— Emily

By tweening I believe you are referring to the process where body parts are positioned at a relatively small set of animation frames, then the computer fills in the in-between frames automatically. That’s exactly how our animators work. They pose body parts and facial expressions at “key" frames they feel are important, and then our animation system software uses mathematical functions called splines to create the in-between poses. If you want to know more, this process is discussed in detail in the Animation Lesson on Pixar in a Box and in the Animation area of The Science Behind Pixar exhibit.
— Tony DeRose; Senior Program Manager Educational Outreach, Pixar

Is the animation of the computer generated grass determined by the actual observation of real grass, or is there some imagination mixed in?
— Kevin

It will start with observation of real grass, but it will be simplified so the computer can handle it. It is also likely to be idealised to make the grass fit in with the look of the film, which is cartoon-style rather than photo-realistic, so will involve some imagination.
— Peter Collingridge; Khan Academy

Do you like to draw or just like to create art in the computer?
— Lillian

Thanks for the question! I like to do both, and pretty often I find that I get the best answer when I use both to get there. I can use a pencil to draw what I want to do, use math to see how to get there efficiently, and put the art and math together in the computer to create the image. I also use drawing as a communication tool with other departments.

Drawing with a pencil helps one practice looking at and understanding form and composition, even if the computer is one's preferred tool for creating images. If you're interested in computer graphics, I recommend you practice making images with both. Best of luck and keep learning!
— Fran Kalal; Lead Technical Director, Pixar

I'm a little confused on the whole rendering process. They said it takes at least around 24 hours to render 1 frame, and that there are 24 frames in a second. If you take a 100 minute movie, then it would take around 400 years to render that many frames. I understand that they would have many machines, but even with 400 machines it would still take a year just to render. My best guess is they have around that many machines or maybe more, and they render as they go so they don't have to wait a year after finishing the movie to render, but I would appreciate a little more explanation.
— Jay

Pixar has a huge "render farm," which is basically a supercomputer composed of 2000 machines, and 24,000 cores. This makes it one of the 25 largest supercomputers in the world. That said, with all that computing power, it still took two years to render Monster's University.
— Peter Collingridge; Khan Academy