1. Split vs. average

hi I'm Alonzo Martinez and I'm a character modeler here at Pixar Animation Studios and that means that I create the virtual characters that the animators used to bring our characters to life and if I do my job right that means that not only people will believe that they're real but also they'll become personal friends right now I'm standing at the Pixar Art Gallery and this place is dedicated to celebrate all of the hard work that goes into making these movies great it's important for all departments here at Pixar to help with a storytelling and for the character Department when we design our characters we tell story through the shapes of our characters one of my favorite examples is from the movie up and that's because Carl is designed like a box and that's because he's jailed in with all of the emotions from the hard times that he's had in life but Russell is shaped like an egg both of these are symbols for who these characters are to create great characters like these we need to make tools that are easy for artists to create those shapes that we are talking about and also at the same time for them to be efficient for the computer to be able to deal with all of that data and that's the topic for this lesson stick around for more in the environment modeling lesson we saw how to describe blades of grass using parabolas but parabolas are just not good enough to describe the expressiveness of characters for example here's a sculpture of Jerry's hand from Jerry's game to describe complex surfaces like this that's where subdivision comes in and as we saw in the previous video subdivision is extremely expressive in the first part of the lesson we'll be looking more closely at how subdivision can be used to create complex shapes and then in part two we'll dive more deeply into the mathematics of subdivision most of the mathematics we use here at Pixar have been around for hundreds or thousands of years but subdivision is different it was actually only invented about 40 years ago and is still an active area of mathematical research the skins of our characters live in three-dimensional space but for now we're going to look at curves in two dimensions starting with a four-point polygon we add more points by splitting that is by adding mid points to the edges I can make it smoother by moving each point from where it is now to the midpoint of its right neighbor we call this the averaging step by repeatedly splitting and averaging we create a series of increasingly smoother curves now imagine that you're an artist at Pixar and you've been asked to create a shape like this one using this next interactive see how close you can get