Hi, this is Brett Morris, and in this video, we'll start to finish up the system by applying wind and turbulence forces to bring the hair dynamics to life. So the first thing I want to do is actually come to our hair objects and over in the Forces tab, let's turn off gravity, because what's going to happen is if we press play, all of the hair is just going to fall downwards, and there might be certain situations where gravity is needed. Obviously, if this is hair that's being applied to a character, you want those characteristics. But for this, we actually want a lot of control. So I find if I turn off the gravity and press play, there's nothing. So the way we're going to control this animation is actually with particle forces, so the great thing about hair is that it will respond to any of these particle forces. The first thing I want to add is actually a wind force. So by default, this will work, because in our hair objects, the force objects is set to Exclude. So if there was a force already being used for another area of the scene and I didn't want to use that, I would add it to this Forces list. Inversely, I could set it to Include, and that way the hair will only respond to forces that are added to the list. So let's actually do that to make that really clear. So now it's set to Include, and I press play. There's no reaction. However, if I add the wind in and now reset and press play, we get a little bit of movement, and we can kind of pivot the camera around, and you can see everything's blowing backwards, because if we take our wind object and pull it out from the center, we can actually see that the direction of the fan is blowing along Z, and that's facing backwards. So, therefore, all the hair is blowing that way. So this is really simple if we want to have a lot of directional control over the direction of the hair, so I'm going to rotate this to 90 degrees, so it's facing in negative X, and I'm just going to position - this is my top view - I'm just going to position this to be on X, and on front view, let's just drop that down. There, so if we kind of come to our default window again, you can see this is kind of a little bit too thick, because we have too many guide hairs. Let's reduce the amount of guide hairs by a factor of 10. So let's just kill a zero at the end of those counts, and we can see our frame again, and let's increase the timeline to 300, and as we press play, we've got great feedback. We're getting faster than real time, and this is really helpful, because not only are we able to see exactly how the animation's looking in real time, but when we render, we can see exactly how it's going to show up, and at any point, we can increase that zero. So these are all really helpful sort of workflow things knowing that you can work quickly, efficiently, without compromising any sort of visual feedback. So the first thing that I'm going to change is actually the segments of the hairs. So right now we're looking at eight, and as you can see when we press play, they're a little bit stiff, and that's just because between every segment when we get a little bit closer, there's not as much detail, so the hair is kind of being forced to bend that way. There's some other things that we could do to loosen that up, but I think for this exercise, it's quite easy just to show that if we increase these segments to 15, the hairs reset. If we reset the timeline and press play, you can see that the hairs can all bend back in a much more acute angle. So we can see that the hair is basically blowing exactly in parallel with our wind force, and for this particular project, I knew that I wanted to have a little bit lower and angle it a little bit more on an upwards angle. So we can say we're going this sort of angle, and if we stop and press play, it is starting to get a little bit more form to it, and it gives a sense of nice movement to complement the form of the play button. So to add a little bit more variation into the animation, we could apply some higher values to the turbulence, but I actually find that if I'm working with turbulence, I actually want to work with a singular turbulent force, because I can work with it independently to dial in the exact parameters that I'm looking for, opposed to working in conjunction with the wind speed. So I'll show that by deactivating the wind, reset the sequence, and let's go to simulate particles turbulence. Now we have to make sure we add that to our hair object forces, drag the turbulence in, and now as we press play, we're going to get a little bit of movement, and that movement is based on the strength. So right now it's five. If we multiply that by 10, it'll give it 50. You can see we got a lot more life coming through the hairs now. This might be fine for many situations, but I know for the particular animation stall I'm looking for, I want the hair to be moving kind of in clumps. I want a larger scale of turbulence, so as I increase this from, say, three, there is a really small scale of turbulence that is affecting along the hair, and as I increase this, the scale of turbulence is increasing, so now we're getting more clumps moving around together, and I believe if I go to about 150, I can really see that everything is kind of moving in a very sort of large sort of swaying sort of motion. So these are the sorts of qualities that I'm looking for as I'm developing animation, and obviously, feedback is really important, so learning the guide count to a reasonable number, we've got great feedback. Okay, so let's turn the wind back on, and when we press play, the wind is going to kick the hair backwards, and then the turbulence is also going to add a little bit of kind of variation to it, and the wind is set to five, and the turbulence is 50. So let's just match those values so the wind actually has an impact, and now we're getting that nice, directional push of wind, but then we've got this nice variation in swaying hair, so if I pause it at any point, we're starting to get, like, a really nice sort of form being created. I think we're getting close, but let's just go back and kind of get this to more of a finishing state. So I'm just going to set the camera to be a little bit more... just to be framed up a little bit nicer. And let's go to our hair guides. Let's jump this back up to 10,000 and 5,000. So let's just start this from the beginning and let it play for a moment, so we can start to see what sort of quality of animation we're getting. We'll actually refine the render a little bit. We'll add a couple tweaks to the hair and then following that, we'll render out the sequence, and we'll see what our end result is. So if I stop at around, let's just let it go to about 60, we can see all these clumps, kind of, moving around. It's looking good at this stage, but around this area, it seems like all of the hair is really overtaken by all the forces, so let's just give this a render and assess what we're looking at. So this looks pretty good. I really like the patchiness of the orange that's coming through. I like that we've got some variation in the color. The lighting is looking really nice. I think there's a couple things we could adjust. I think the tips are maybe a little bit too wide, so let's just drop that down to point one, and maybe let's set the thickness to point five. Let's add some variation of point five as well and see how that looks. Yes, I like how we're starting to get a little bit more of a tip, and the thickness variation definitely kind of plays a big part. I think maybe the blue could use a little bit more hue variation if we jump that up to 15. Maybe some value variation, say, 10. I'm just trying to look for nice color variation across here. Maybe 15 is too much. Maybe let's see how that goes. Yeah, I think it's getting better. I think the yellow is looking really nice, but I wouldn't mind maybe a tad more variation. Yes. That's starting to look a little bit better. The great thing about the hair material as well, is if we select both of these, we come back to our basic tab, we can actually add more characteristics to the final render quality of the hair just by activating some of these channels, so I know kink is always favorable, and if we just render that, you can see everything's going to look a little bit crazy, and that's fine. Let's just reduce the value down to, say, 10%, and maybe that's too much. Let's just go 5%. And you can see there's just a little bit of variation. The hairs aren't super straight. It just gives it more of a shaggy sort of feel. Let's see if there's any other ones we want to activate, maybe frizz just by turning it on. That's obviously pretty wild, but let's just dial these parameters back. We're always just looking for like a little bit of irregular variation for hair, and I think this is looking pretty good. And to give some context about how we work to have this in the production of the actual project, we followed this procedure almost step-by-step. We created the system, we styled it just as we're doing now, and then we just render out a sequence like this, 300 frames or so. And then when we're putting together the edit, we're really just looking for these like key moments of really interesting animation that complement the edit. We're always building shots around each other. So in the edit, as the play button kind of zooms out, we've just got this, like, a really nice flick of the hair, and that really just came about just selecting like a really nice moment of the animation sequence that we rendered out. So let's prepare this for rendering just by setting our camera. Just make sure our parameters are kind of centered up, and this looks pretty good. I just want to frame that up to be nice and square, and hit a render. I think maybe we can reduce our fill light a little bit. Let's actually go half. Let's just see what happens, and it may be too... It's not too bad, but let's just go to, like, 20% and increase our key light. So let's go to, say, 120, yeah, maybe 115. Okay, so I'm pretty happy with the way this has turned out, and going through all the steps, hopefully you've been able to follow along and create something as visually interesting as this. I actually set off a render earlier and have a little bit of animation to check out, and this is what we're looking at. So you can see we've got a nice sort of flowing of the wind, the turbulence is giving everything a little bit a life, we've got this bright to dark lighting, the color variation gives everything a really nice style, and overall, I'm pretty happy with it. In this lesson, we went over adding wind and turbulent forces to the hair to bring the dynamics to life and in the final episode, look at quickly preparing a new object and then moving this hair system to another.