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Current time:0:00Total duration:1:44

Video transcript

(jumping, bouncing) (light switches on) - Great work. So far we've built up a model of hair using a series of damped springs. This gives us a more realistic behavior, like this style I came up with. But remember, the art department wants Merida's hair to be curly. Sometimes it curls up while moving but it doesn't hold that curly shape while at rest. Here's an idea. What if we put some smaller springs in between the larger springs to pull them together? Let's call them support springs. We already have a mathematical model of the spring so this is easy to test out. If I connect a support spring between the larger springs, I get something like this. If I hide the support springs, you'll notice the hair comes to a rest in a curly shape. That's much better. Adding these support springs results in new parameters we can control. The stiffness and length of the support springs. Shorter support springs will give us smaller curls, while really long support springs give us bigger ones. And if we make the support springs have a higher stiffness the curl pops up like this. Kind of like we applied hairspray. Compare this to support springs with lower stiffness. In this case, the curls relax a bit and fall downwards in a natural way. Now, let's try this with a bunch of hairs. Now that's starting to look more like Merida. This isn't exactly the method we used on Merida for the movie, but it's close. In this next interactive you can try this out with all the parameters we've introduced. The two new parameters are support spring stiffness and support spring length. See what you can come up with.