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Current time:0:00Total duration:4:37

Case study: The Good Dinosaur

Video transcript

so far we've been exploring what a software engineer does at Pixar which is creating the tools used in the filmmaking process such as a hair simulator and all the parameters artists can control the person actually using these tools in each film is known ethics art as a technical director to better understand this kind of work we've invited Jakob Brooks a technical director who has used hair simulation in our films hey [ __ ] hey Sariah pretty good so you worked on spot for the good dinosaur I did I did yeah so what were their artistic goals for spots hair well spot was one of those characters that you knew we wanted to fall in love with right away so he had to have a lot of Appeal in him but he also kind of straddles that world of being in the wilderness so he's got to look wild and a little unkempt so with his hair we were able to kind of bridge those two worlds so that you can still get that feeling of kind of a matted tangled kind of wild animal feel to him but also get that appeal of like there's a child who wakes up in the morning and has adorable Bed Head so it's just super familiar to us so for for the hair as far as the texture goes we knew we were going to have to have strands that were intertwining and felt like they hadn't been washed in a while not going towards that growth factor but something that definitely feels entangled and unkempt and but also just kind of hit those shapes that we knew we would want to just frame his face nicely and be appealing so that he does have that genuine appeal in the film so how did you model the hair to meet these artistic goals well before we can actually simulate the hair on a character that's moving like spot as he's running around the film we actually have to groom there we have to model that shape and for spot it was an interesting challenge because his hair is so tangled it becomes a very important thing to make sure those hairs aren't intersecting in your ways and that you could feel that the hairs are actually twisting around one another in order to do that we ended up using a technique that was developed at Disney Animation where we're using geometric tubes to shape gross shapes in his hair so that you could really get the appeal of individual clumps of hair and see how it tapers along towards the end of the hair so with those tubes once they're shaped in a certain way we fill those tubes with curves and those are the curves that we end up simulating as we go forward now that you have the shape that you want it how did you set up the hair simulation to get the look that you wanted yeah the the sim of the hair for him is it's obviously a little bit different as well because you've got this mangled mess of hair it needs to hold that shape and it doesn't move like even your hair would or someone will straight her hair so it doesn't hang with gravity like you would think as a whole for spot his his hair is a little tighter than most of our hair the springs are a little bit tighter so that you don't get quite as much sag and it really does feel like it's been teased and frazzled and kind of it holds up and defies gravity a little bit more than natural like longer hair would be so spot had variation for his hair like when he was wet so how are you able to do that because he was in the wilderness and we knew there was a bunch of weather changes where sometimes it's starting to rain sometimes it's in the middle of the rain where it's getting heavier and sometimes he's soaking wet because he gets in the river my colleague David Lally and I worked on something to where we started thinking hey wouldn't it be cool if we just change simulation parameters to get the hair that he started with to be the hair as it changes and so he started on the soaked version of the groom and by changing things like the the stiffness of the springs we could lose that groom shape that was all spirally it would make it kind of flattened out we would turn up the gravity so that it hangs a little bit tighter to his face so what that allowed us to do was change the simulation parameters a little bit of a time so maybe gravity would get a little bit stronger or the springs would get a little bit looser so that you could get a variation of that transition from dry to wet but you had various stages in the middle that you could get which normally if we were just doing independent grooms we would have more of this kind of on and off switch of like it's dry it's wet now we could get a nice blend through that change that's pretty cool thanks Jacob for coming by and now on to lesson two