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Hair simulation overview

Overview of this lesson.

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  • duskpin seedling style avatar for user Emily Walter-Difranco
    So, im a little confused on why hair simulation has to be animated all at once. why can't they have two or three similar shaped, placed, and colored locks of hair get moved by the same animations, without having to animate them individually?
    (9 votes)
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    • purple pi teal style avatar for user Awani
      if similar locks of hair get moved by the same animations, then the overall effect wouldn't be realistic as each lock of animated hair would move exactly the same and respond to stimuli like water and gravity in the same way;unlike natural looking hair, and this is what makes animating hair all the more challenging
      (8 votes)
  • aqualine ultimate style avatar for user uthmanigbin
    anyone knows which software they use
    (4 votes)
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  • aqualine seed style avatar for user sree vivek
    what program does dreamworks use?
    (5 votes)
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  • duskpin ultimate style avatar for user pandaz461
    Hair is obviously not a singular object(tiny strands), and does that mean when drawing/2D animating that the same rules apply, unless the hair is being stopped or pushed back(by a headband or hair clip, for example)?
    At , she refers to the spring method.
    And does the spring logic apply to straight and wavy hair?
    (4 votes)
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  • scuttlebug purple style avatar for user dh_a_ra_a
    please somebody answer my question i need to tell somebody
    (2 votes)
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  • duskpin ultimate style avatar for user Rose
    So in the computers point of view the hair is a bunch of springs?
    (2 votes)
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  • leafers sapling style avatar for user Samantha Wilmes
    I had no idea that it was that difficult to make hair look great in computing!!
    (1 vote)
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  • blobby green style avatar for user simpsonj
    how can i make good animatios on youtube
    (1 vote)
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    • female robot ada style avatar for user Katey Gordon
      Hi simpsonj,
      What a great question the thing is with Animation there is no secret to making good Animation's on YouTube as I am doing 2d Animation myself on YouTube it comes with practice Everytime you practice your improve your skills now here are some things you can do to make your Animation better.
      1.Keep practicing on Khan Academy and learn from the pro's
      2.Ask your family and friends for feedback on your videos often times art is reflected based on the people around us.
      3.Work on colors often times certain colors work better together
      4.Develop a Story and storyboard to improve the outcome of what your animating.
      5.Have fun and do what you love and know in your own artwork often times it's the greatest place to start!

      Proud to be a Khan Academer
      Katrina
      (1 vote)
  • duskpin ultimate style avatar for user Dana
    How do they incorporate invisible core strings like the physical example she showed us into the Merida's hair to keep each strand's shape when in action? Is it done by affecting the physics or something?
    (1 vote)
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  • aqualine ultimate style avatar for user pierce
    i have a question for hair and fur in video games how would that work? would it be made the same ways?
    (1 vote)
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Video transcript

Hi, I'm Hayley Iben I'm a software engineer at Pixar. I worked on the hair simulator for the movie, Brave. Hair was a really big deal in Brave. It was a symbol of freedom that was intrinsic to our main character Merida's personality. And making hair that feels right, meaning messy, wild and free, is a hard thing to do computationally. In our movies, hair is a simulated effect. That means no one animates its movement by hand. The way it moves is defined by physics and programmed into the computer. To figure out what hair simulation should look like, we needed to look at real curly hair and see how it worked. What we found was this. Curly hair forms together in locks that reshape themselves when you pull on them, kind of like a spring. This was great news because springs can be modeled mathematically, meaning we can simulate their behavior using a computer program. From the computer's perspective, Merida's hair is just lots and lots of springs that react to forces, such as gravity, as Merida moves. The tests we ran using this approach were pretty good, but not quite natural enough. While stiffer springs held the shape of the curl, it didn't bounce like natural curls. When we made the springs loser, her curls would unwind when she moved. This was even more obvious at high, often unrealistic speeds, found in animation. We realized we needed something to preserve the structure of the curl, but not impede the overall motion of the hair, kinda like digital hairspray. (can hissing) Oh, sorry (laughs). We came up with the idea of connecting the springs that make up Merida's on-screen hair to invisible core springs like this. The core springs would limit the movement of the on-screen hair when the motion was more extreme. This way, we could have the best of both worlds. Our original simulation we create motion that was soft and natural, but the core springs would keep the curl from unwinding too much. Figuring out how to make a hair simulation system that could help us achieve the feeling we wanted for Merida's hair was hard. It took a lot of iterations to get it right, but it made a big difference. Merida feels like a real girl, messy, wild and free.