Support springs

great work so far we build 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 once 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'd get something like this if I hide the support Springs you'll notice the hair comes to 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 use 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