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Current time:0:00Total duration:2:08

Video transcript

we actually do a lot of simulation at Pixar things like fire water and explosions are handled by the effects Department you can learn more about that in the effects lesson the simulation department who I work with handles and emotion attached to the characters epics are like clothing and hair but we can't move every hair on a Pixar characters head by hand that would drive our animators crazy instead we use physics and computer programming in this lesson you'll learn how to simulate hair the same way we did for Merida in the movie brave here is an example of a shot of Merida that the simulation Department got from the animation Department on the film brave the animators have created the main action in the scene and now it's our job to fill in the missing details such as the motion of cloth and hair everything we do begins with modeling the problem we want to solve in this case we need a physical model of Merida's curly hair so let's begin with the very basics what should our model of hair look like well hair is kind of like a mop just a bunch of strings but strings are actually quite complex to model mathematically because they are so bendy modeling them requires a lot of computational power due to all the calculations involved this is why we are always looking for ways to simplify our models for example we could take a bunch of paper clips to model a strand of hair we first draw a series of line segments connected to particles like this the computer needs to calculate the positions of these particles but first we need to describe what forces are acting on them in the real world each particle is affected by three forces the force of gravity and the forces from neighboring connections like this next up I have an interactive program for you to see this in action you can adjust the following parameters size of each segment number of segments per hair number of hairs and the force of gravity explore these primers to see what kinds of looks you can come up with have fun