Transcripts
1. Introduction: If we're creating something that's 100 percent identical to the real world, then it might not be all that interesting. But if you don't base your animations in reality, it will be very apparent that something is just not moving right but you can make graphics that mimic real life, but still give it a little bit of playful personality. Hey, I'm Jake Bartlett, and I've been a motion designer professionally for the last 10 years. I'm currently based in Denver, Colorado and I've been teaching on Skillshare since 2013. So in today's live class, we are going to be talking about physics and weight in animation and why getting it wrong can really hurt your motion and confuse your viewer and how to get it right inside of After Effects. I chose this topic because it's something that I see a lot of animators and motion designers struggling with. It's something where if you get motion of physics of something that should be moving in certain way wrong, it's really easy to be picked up on as just appearing of. So that's why I really want to cover this topic and show you how you can handle that. To teach you these things, I'm going to be showing you a few examples of things that don't look right, and then how to fix those things that don't look right and then we're going together and work on an exercise where we take three different objects of completely different weights and masses and see how we could approach animating each one of them falling to the ground. To be able to participate with me today, just grab the project file in Project and Resources tab, and you'll just need a copy of After Effects to be able to follow along. The great thing is though, that the principles that we're going to be talking about in this class are applicable to any form of animation. You don't have to use these in After Effects. You can apply it to 3D or stop motion or any type of animation and it's just a universal principle. Just so you know this class was recorded live, so during the exercises I was interacting with students. All right, I'm ready to go, I hope you are, let's jump in After Effects.
2. Why Physics Matters in Animation: Hi, my name's Katie. I'm a producer with Skillshare, and I'll be the host for today's live session with Jake Bartlett. Jake, if you want to give us a little intro, who you are, what you do and then we can kick off into it. Great, thanks Katie, and thank you everyone for coming. I am Jake Bartlett. I've been a motion designer professionally since 2010, and I have a t-shirt to prove it, so you can trust me. We are going to be talking about physics and weight in motion. It's really important to think about physics in your motion design when you're trying to animate something that has physics involved. If you think of an example of something as simple as a bowling ball being dropped off of a building, you want to animate that in a way that the viewer is going to interpret as realistic. It doesn't have to be a 100 percent physically accurate because with animation and motion design we're imitating life, we're not perfectly replicating it. If we're creating something that's 100 percent identical to the real-world, then it might not be all that interesting. That's where we get to have some artistic freedom and direct the motion to be a little bit more playful. But if you don't base your animations in reality and think about the way that objects should move, the viewer is going to see that as off. Something about it will be wrong and it'll be very apparent that something's just not moving right, even if they can't put their finger on what exactly it is. What I want to start with, is showing you this example of some physics that are a little bit off. Originally, I was thinking about searching the Internet for other people's work, but I didn't want to throw anyone under the bus. So I recreated an example of something I saw a lot of, which is just physics that, the motion itself might be okay, but the physics are off. I'm going to play this animation of just a bouncing ball moving down the street. It's okay. The design, the colors, they're fine, but something about this doesn't look right. I want to talk about what that is. I'm just going to go to the ball layer and show you the keyframes that I have set. We have position and rotation keyframes. The ball moving up and down is the position obviously, and then we have the rotation that just accents, the moving forward. If I took those rotation keyframes off, this example would still play the same. Something about the ball bouncing is off. What really is going on here, is that these three keyframes are just the default, easy, ease. There is no modification to the timing or the spacing between the timed out keyframes. The points of contact on the ground are correct and the peak in the air where it hits its crest, those are correct, but what's happening between those keyframes After Effects is just defaulted, the easing for the user and it doesn't look right. If I go into the graph editor, I can see how After Effects is filling in those in-between frames. That's called interpolation between keyframes. This graph is called the speed graph, and it's a representation of how fast an object or how fast a value is changing over time. At the key frames, which are these three points, it's at a baseline of zero. The ball is not moving when it's touching the ground and it's not moving when it's up in the air. Those are the two points where it's not moving at all. Then, these arcs are how the speed or the velocity of that property, the position property, is changing over time. Right here, halfway up the path, here's the motion path. That's where it's traveling the furthest and it's just easing in and out of these two points. But if you think about a bouncing ball, that's not really how it happens. When something's coming down to the ground, it's not going to slow down and ease before touching the ground, and then gradually just ease off of the ground. Again, that's just not physically accurate. What can we do to fix this?
3. Ways to Fix Physics & Motion: Now let's look at the tools that we can use in After Effects to fix these issues and actually start to have a little bit of fun with our animation. The first thing I want to do is actually separate the dimensions of my position property because right now the position property is controlling both the x and the y. That is forcing me to use the speed graph, but there's another type of graph in After Effects that makes this type of work a lot easier. So to do this, I'm just going to right click on the position property and say separate dimensions. Now I have an x position and a y position value. I actually don't need the x position that's the horizontal axis because it's not moving left and right, so I'm just going to deselect and click on the stopwatch to get rid of the keyframes on the x position property, and that way we're concerned with just the y position. Now, down here in my graph type and options menu, I have it set to auto select graph type and After Effects is going to basically guess which graph you want to be using based on the property that you're viewing. Because I separated the dimensions and I'm no longer using two values in the same property, it switched to the value graph automatically. If you want to go straight to that, you just go to edit value graph instead of speed graph. But this is instead of a representation of velocity over time, it's now just a value overtime. One second in time at this first keyframe, the value of the y position is 777 pixels. As we go forward, halfway through at the peak of its jump, it's 361 pixels. So it's just giving us a different look at the motion, instead of speed its value. I'm going to grab these three keyframes again and easy ease them just like they were before so you can see what easy ease keyframes look like in the value graph versus the speed graph, which I can switch back and you can see it there, it's very similar. But it's just showing it a little bit differently. But if I play this back so you can see, we're back to where we started. This is exactly the same we're just dealing with one property instead of two now. But if we just read this graph, then we can predict what it needs to look like in order to have a more realistic motion. If you were to drop a ball and it hits the ground and then you think about what's going to happen next after it hits the ground, because that's where we are at the starting frame is where it makes contact. It's not going to ease back up, it's going to pretty equally as quickly as it fell down, jump back up. We don't want to ease out of this value into this one, we want to come into it add more of this kind of a curve. I'm just going to grab that handle, and modify this so that it's a downwards curve, meaning we're not easing out of this keyframe at all, we're basically shooting out of this keyframe, we're speeding up a lot more. Then we're going to get to the top slowdown, because eventually it's going to react to gravity, it's going to stop rising in the air, and then it's going to fall down again. But again, we're not going to ease into that downward position not hitting the ground, we're going to pretty quickly gain speed until we've made contact with the ground. Because as something is falling, it's gaining more and more speed until it hits something. We want to take that easing off on this side too, so we're getting more of this U-shape now. If I play this back, it's better. It's not there yet, but it's already looking better because it's gaining speed as it comes down and it's losing speed as it goes up. What I want to do next is just grab this middle keyframe. This is the point where it's at its peak, and just basically ease into that keyframe a little bit quicker and ease out of it a little bit longer. I'm going to grab this handle here, hold down the shift key, so that it stays on the horizontal axis. Then just pull this out a little bit more so it's a little more rounded on both sides, and then maybe bring this one out just a little bit, same thing over here. I'm trying to be pretty symmetrical with my handles, and then play that back. Just with a couple of minor tweaks, we went from something that looked off, to something that looks pretty accurate. If I easy ease this again, this is where we started, and undo, and this is where we got to. Just by modifying a couple of handles. This is something that come, like when you practice this you're going to be able to pick these things out really quickly, once you get into the value graph and you start pulling these handles around and understanding how it's all working, you're going to develop a sense for why something looks off, and be able to troubleshoot that really quickly. Now we can really exaggerate this. This is pretty, I'd say pretty close to physically accurate. We don't know exactly the properties of this ball obviously, but it looks pretty good. But we can always exaggerate motion, that's actually one of the principles of animation, is exaggeration. You're allowed to like I said go from basing things in reality to exaggerating reality. I could make this pop up in the air superfast, hang on to that keyframe for much longer, so that it looks like it's just really hovering in the air, like it has a lot of energy almost like it has control over how quickly and slowly it's jumping up and down and it just looks a little bit more playful. That's the basics of how to handle an object bouncing up and down in After Effects. We're going to get into another example where we get to do some more playing around. But I just want to show you how modifying a few of these properties can really make a big difference. For example, on this y position, if I grab the y position keyframe or property and the center keyframe right here where it's at it's peak. If I bring this up higher, this is going to change how everything feels because it's now covering a lot more distance. Another thing that you really need to think about when you're animating something like this that's bouncing, is the timing of the keyframes. This amount of time might be too quick. We might need to bring this out further and this is probably going to break some of my other animation. But I'm just illustrating that maybe you need to work on not just the spacing of the keyframes and the values between the keyframes, but you also need to work on the timing between those keyframes as well, so that you can get an accurate speed and develop just a visual language basically of how your objects should be moving or shouldn't. It really makes a difference into the weight of your object and how the viewer is interpreting that weight, when you modify things like this timing and how high it's bouncing. If we wanted we could make this go in the opposite direction, make it bounce a lot closer to the ground. Have it bounce a lot quicker. Then maybe hugging that middle key frame like we did with the value graph here isn't going to work out so well, because it's spending so much time off the ground and we barely see any in-between frames here. Maybe I'll just ease that again and pull them out just slightly, and maybe even ease just slightly out of these two outer key frames. Now, we just have something that looks like a little bit more of a hop rather than a big balance motion. That's the basics of how we handle things like this in After Effects. I'm going to undo back to where we were with the regular height. Couple more undoes, there we go. Something like this. Since we separated our dimensions we're now controlling the x and y position independently of each other. Because of that, we can do some really fun things. I'm going to move the x position over here just to this side of the animation, ensure that the y position animation has been preserved. Its independent, so it's happening on its own. We're losing the placement of these accents, so I'm just going to turn that off for a second. But if I set a key frame on the x position and then go forward to the other side of our animation and set a key frame and move this over, what would happens to my motion path? You see how we get that arc now. That's because these two properties are being combined so we're getting this linear movement on the x position, but this ease movement on the y and it's creating an arc. If I duplicate these key frames right here: the position and rotation, and I'll need to just quickly modify my rotation to go two forward instead of just one cycle forward. Then we doubled our loop, and now it's going to jump forward and then bounce straight up. This needs to be a one. Now that we've controlled these with two different properties, I can play around with the x position independently of the y and I could just have this ball hopping all around and we can continue duplicating this loop. I'm just going to copy the position key frames for now. Let's just say we have it hop around four times before it loops, so it's going to go forward, backward, forward, and then end up right where we started, We have that x position again. All of these key frames are linear, but we're still getting these nice arcs because of all the easing we have on the y position. I'm just going to double-check, all of those are exactly the same. We play this back, the ball is just now hopping around; going back and forth. It just gets to be fun for me at this point. I feel like I'm just playing instead of working which is one of my favorite parts about motion as I'm bouncing. Let's say that on the second bounce, I don't want it to go quite as high. While looking at this value graph on the y position, I'll just grab this point and drag it up. You can see that this shape is being mirrored by my motion path. This is why I love working with the value graph because, when you're separating dimensions on a position property and you're looking at both your computer and your graph editor, they're mirroring each other and it starts to make a lot more sense how they're interacting. But let's just say the second bounce I'm going to make it about that high, the third bounce will drop it down a little bit less, and then that last bounce will be very similar to the first one. I'll play all that back and we just got something that looks a little bit more fun. That rotation property, really I should bring that out to five seconds and probably increase the amount of times it rotates. Or why don't we do this? I'm going to have it rotate forward at this first bounce and then we'll have it rotate back a little bit on the second bounce. The bounce would rotate forward a whole bunch and then on the last bounce, we'll just have it get back down to where we started. Now, it's going to have different rotation values as it's moving forward. Like I said, it's just fun, it's playful. Once you start to understand how these graph editors work, it's like playing. Hey Jay. Just a quick one from Lexie. How do you see the path of the motion to the blue line? She's not seeing on the screen. On a PC, it's Control Shift H. That's your overlays. On a Mac it would be Command Shift H. So go up to View, Show Layer Controls. That is what I was toggling right there. That's how you see the motion path. Really quickly, I just wanted to show this example that was on the class page, the live session page. This is something I did awhile ago, I just want to point out an example of how you could take this idea and really exaggerate the motion. Replace this box with a person in the real-world. Think about if they were getting ready to jump up there's not going to be that much hang time. They're not going to jump and just hover there for a second while they twirl around and then gracefully bounce down to the ground and squash. That isn't the real-world at all. But if I were to just animate that, it wouldn't be that much fun. That's where taking this idea of basing in reality but then exaggerating it to add playful personality, is what I love about animation. I'm going to talk about what the animation principles that are being used here really quickly just to give you an idea. The first one is anticipation, and that's when this box squashes down and twists, that is anticipating the motion that is about to happen. Then it leaves off the ground and it jumps up real fast. Right here it's actually stretched out rather than squashed down. That's another animation principle, it's called squash and stretch. Then there's an animation principle of exaggeration which we've talked about already, exaggerating your motion and the movements to get it to be more playful. There's another one called slow in and slow out, which can be interpreted as ease-in and ease-out. That's literally what we've already done, which is modifying those handles to ease all of your motion. There's a lot going on in a simple animation. Like I said, once you get in there and you start doing these things and practicing it yourself, it becomes second nature and you just have fun getting to design how something is moving. Let's move on to our actual interactive part of this session.
4. Animate a Falling Tennis Ball: Now that we know how to use these tools, let's start animating. We're going to start with a tennis ball. If you want to follow along, go into the object and drop calm. We have three objects. What I want to do is basically throw them or drop them from the sky, and think about how each one of them is going to come down, hit the ground, and what they might do. Let's start with the tennis ball, is going to be pretty similar to what we've already dealt with. I'm just going to move the feather and the cinder block out of the way, so we can focus on the tennis ball for a second. I'm just going to check, make sure I'm not skipping anything. Yeah, I think we're good. What we want to do first, is again bring up the position property appear on the keyboard, and then separate these dimensions just like before. Right-click on that position property and say separate dimensions. That will give me access to both the x and the y. I want to set a keyframe down here at the bottom so I know where it needs to hit the ground, but then I'm going to move that forward. We'll go one second forward, so two seconds, I'm starting at the one second mark. Then just back this up to be pretty high. Maybe right about there and play it, it's a linear animation. Very boring, not accurate at all. What's the first thing we do? Almost always, easy ease the keyframes. Right-click Keyframe Assistance Easy Ease, or the shortcut is F9. That will give us basically the same animation that we were seeing with that ball bouncing where it's easing out of one position and easing into the next. That doesn't look right, so we're going to go into the graph editor, and start working on the actual easing the timing of these keyframes. Again, I'm looking at the value graph. That's what I suggest you used on this. What we want is to ease out of that first keyframe, so that's fine, but then we want to gain speed all the way until it hits the ground. It should be having a greater change in value all the way until it collides with something. Let's play that back. Now, one second is probably way too long for that ball to be falling. Let's back it up to 12 frames. By the way, I am working at 24 frames a second, that's just a traditional frame rate for animation, but this applies to whatever frame rate you're working in. Let me just ease these keyframes out a little bit more slower. We're hanging in the air, we're pretending like this ball just appeared out of nowhere and is suddenly being introduced to gravity and having to be pulled down to the ground. I'll play this again, and it's just gaining speed all the way till it hits the ground. Great. What happens next? Well, it's going to bounce off the ground with basically almost an equal and opposite force. According to physics, it's going to lose some of its velocity on its way back up. It's not going to bounce all the way back up to where it was. But if I go forward another 12 frames, then I'm actually not going to grab the y position and bring it up again, and I'll show you why in just a second. I'm just going to set another keyframe exactly the same as what we already had, which was this button right here adds another keyframe. Then I'm just going to go another 12 frames forward, set another key frame, and then go 12 more frames forward, set another keyframe. The ball drops and then nothing happens even though we have more keyframes since they're all the same. But if I go into the value graph, I can do something interesting. If I just grab the line between two keyframes, just click and drag, see how I can just bend that out. That allows me to without a second keyframe in the middle here, it allows me to just modify that path because it's controlling the interpolation between two keyframes. It's modifying what's happening between them. I am going to uncheck this transform box right here, so it's not in my way. But what this is going to allow me to do is just get a starting point for my easing. I should point out what I'm doing here. If you look at the angle of this handle right here and the length of it, I'm trying to match that angle and length on the opposite side. That way it's just basically coming into this keyframe with the same amount of energy as it's leaving that keyframe with. Those are symmetrical handles, then it's going to be moving basically at the same speed on either side of that key frame. But then on inside, I don't want it moving quite as fast. I want it to start losing some of that momentum and that speed. I'm going to try and keep the angle, but then move it down just a little bit. Then I'm just going to repeat this process for the other two sections of keyframes, but decrease their values a little bit at a time. I'm going to zoom in so I can see this a little more clearly. You can zoom in on the timeline with plus and minus and then hold the Space-bar to temporarily pan, and then let go the Space-bar to get back. But basically I want to match this angle to this angle just to make it shorter, and then mirror it on this handle, and then bring this one to be a little bit less. Then I'll do it one more time. I'll grab this handle symmetrically to that one, and then a little bit less on that one. What I've created is called a decay curve, where this is base. Let's play it back first and we'll see how it looks. Okay? Yeah, a lot of things to talk about here. First of all, some things off. The biggest issue that's off is the timing of the keyframes. I evenly spaced these out, so there's 12 frames between each one. But in reality, this ball is going to bounce less high with every bounce, meaning it's going to take less time to contact the ground again with every bounce. The first modification I'll make is just shortening up all of the gaps between keyframes. Grab a keyframe, hold down, Alt option on a Mac, and press the left Arrow key to nudge it over. I'm just going to shorten this up a little bit at a time. Instead of 12 frames between, here and here I put 10. Then we've got 1, 2, 3, 4, 5, 6, 7, 8 is where I want this next one, and then 1, 2, 3, 4, 5, 6. These are arbitrary values like I'm basically just guessing, but that's how animation goes. You just work on the timing. You adjust things, and then you play it back and see if it looks good, and if you're happy with it. Let's play that back again. Just quickly. Can you create these keyframes using the pen tool? That's a good question. I've never really thought to try that, but let's see. Yes. Yeah, these curves are basically vector paths, so you can use the pen tool to add and modify keyframes in the graph editor the same way that you could in a motion path or a shape layer vector illustrator artwork, you can use the pen tool and the graph editor the same way. I do not believe, if we go to the speed graph. No, you can. It doesn't behave the same. You see how I can't adjust the angle of the handles. That is one reason why I prefer the value graph. Because look at this graph, that is much more difficult in my mind to understand what's happening. Then this one right here. I can actually show both at once. This one right here, the weird one is the speed graph and that's telling you how fast the object is traveling over time. But as far as a visual editable way of modifying your motion, the value graph just makes much more sense to me. But yes, if you want to use that pen tool, you can absolutely do that. I'm basically using the same functions at the pen tool will give you just using the selection tool. This is actually a really good point. Let's say that you wanted to bring these handles out, again to be symmetrical or locked in either direction. You're going to want to grab that pen tool, which I think I've been doing temporarily just by holding the Alt key on the keyboard. Then if I click on that, it removes the handles. I can click on it one more time and it puts them back. But now they're locked together. I can break those again just by holding Alt, clicking and dragging, so we get back to where we were. Once they're broke and you don't have to hold down the Alt key anymore or option on a Mac. But yeah. To answer your question, you can use that pen tool. Let's get this back to where it was bouncing before. We were talking about the decay curves. With every bounce, it's taking less time to cover the amount of time that it's in the air. I arbitrarily basically just picked out those key frames, so I think there were 10 here, 8 here, and then 6 here. Let's play it back one more time and see what it looks like. I don't think it's bouncing high enough on the first bounce, and I think it's taking a little bit too much time overall still. I'm going to grab all these keyframes except for the first one and just back it up a couple of frames, and then increase the height of this bounce just a little. I don't want to go this far, but maybe halfway. I'm sure there are actual physical formulas that you can look up of how much energy it's going to lose with every bounce. But again, I'm not trying to be 100 percent physically accurate, I'm trying to make something that's just visually interesting. I'm just going to continue modifying these handles. I think I talked about this a little bit already, but I'm making a decay curve. Decay means that it's just losing its momentum or its energy as time goes on, so with every bounce it's bouncing less and less. But it's doing that in a compound way. So with every bounce it's losing more energy than it lost to the previous bounce. If you were to draw a line from this key frame to this key frame; just a straight line, you see that these curves are not reaching to where that straight line would be. Because that would mean that each bounce would be losing an equal linear amount of energy per bounce. A decay curve is more where it's curving like this. If you were to draw a curve from this key frame to the peak of each one of these arches, that would be more of a curved shape. That's going to give us a more physically accurate looking bounce. I think this last bounce is probably going a little too high, so I'm just going to modify that a little bit and we're almost done with this example. Let me grab this last key frame. Just bring it in one frame and we'll play that one more time. As you've seen, I've been constantly tweaking these handles and the timing of the keyframes. This is something you can play with all day, but it's also something that you get to add direct. With every animation, you are the motion designer, you get to choose how things are moving. If you think this is moving too fast, space them all out. A really quick way to do that is just grab all these keyframes, hold down "Option" or "Alt," and then click-and-drag on the last key frame and you will proportionally space out all of those keyframes. I'll just drag this out to three seconds, and we'll play that back and see if that speed is a little bit better. I don't know that it's better or worse, but it's a very easy way to modify the timing of your bounce. I'm going to go back to where we were, and really quickly show you again how incorporating the x position can make something really interesting happen. This is currently just being dropped from the sky and staying in that one exact spot, but what if you were to throw that ball? Well, even though we've already animated the y position, we can easily make that type of animation happen. If I move this ball off to the side of the screen, so outside of the cop, we set up an x position key frame right there. Then I go forward to where it's done bouncing. I can just click-and-drag this out. Again, look at that motion path, we're now seeing a bouncing animation motion path happen. With just including those two x position keyframes, our ball is now traveling across the screen. We need to add in some rotation obviously because of those lines, they doesn't look very accurate. So let's just add a rotation key frame, Alt Shift R on a PC, Option R on a Mac, and we'll just have it rotate maybe two times forward. But we still have an issue. A ball is not just going to bounce, and then suddenly be frozen. It's going to stop bouncing but then roll a little bit before it comes to a rest. I'm going to go forward, let's say five frames, 1, 2, 3, 4, 5, and then move the x position out just a little bit more as well as rotate it just a little bit more and play it again. So bounce and roll. Now we can work on what's not looking right. I think one of the biggest issues is that it's not covering enough distance, so I'm going to grab that x position and move it out a little bit. But then I'm going to go into the graph editor, and you'll see that this value is changing basically completely equally over every frame. Even though we get to this point and then it keeps going, it's traveling at the same speed and really it needs to ease into that final resting point. What I want to do is ease out of this key frame, and I'll do that by holding "Alt" or "Option" on a Mac, clicking-and-dragging as well as holding "Shift" so that it locks into that horizontal axis. But this is causing a weird shape. I want it to basically be traveling or changing at a constant rate until this key frame, and then ease into that. At this point you can see that it's just slightly curving up before it eases in. What I need to do to correct that is just grab this this key frame right here and bring it up. I'm holding Shift as well to only move on that vertical axis. Now its basically traveling in that straight motion and then curving out. It's never speeding up, it's slowing down and easing into that final position. Let's play that again. You can see that now it's a lot more gradual. I could probably even extend that and ease into that a little bit more, and maybe even increase the values a little bit. So it skids out there a little bit more. Another way we can correct this is just dragging it there, or having it take more time to get to that resting point. I think that's pretty good. We just need to work on the rotation, which would be right here. That's what's wrong, is the keyframes aren't lining up. Let's grab that rotation. We need to ease into that as well. You see how this graph looks almost identical to the x position, and it's because we're doing basically the same thing. It's rotating at a constant motion until it hits the ground, it's no longer bouncing, and then it needs to ease into that final value. I can sit here and tweak this all day long until we get something that is perfect, but obviously we have more ground to cover. I want to move on to our next example.
5. Animate a Falling Cinder Block: Now we're going to switch gears and do something completely different and we're going to animate a cinder block falling. Just to keep this tennis ball in place, I'm going to grab these exposition keyframes. Actually, I'm just going to shut it off. Let's just do that. Bring the cinder block back, and let's do the same thing. First, I'm going to open the Position, right-click and say "Separate Dimensions", and then we need to lift this up into the sky. We'll set a keyframe on the ground. We'll put that at one second or actually two seconds. Just like before, we'll do the exact same process. Move this up to the sky, and then easy ease these keyframes. So F9 on the keyboard is the shortcut. That obviously does not look right. This is something that's very heavy, and it's going to just slam into the ground. So we want to ease out of that first keyframe and then slam into the second keyframe. One second is clearly way too slow for this one, so let's just go maybe eight frames or 10 frames forward. Then really ease out of this keyframe, this first one, so that it hangs there before it picks up speed and slams into the ground. Now it looks like it's really grabbing that gravity and hitting the ground, but what's going to happen with this? It's not going to be the same thing as the tennis ball. We're not going to just bounce it back up in the air and do this weird cartoon motion. It might not even bounce at all. So how can we animate this in a way that seems a little bit more realistic if it doesn't bounce? Just to show you, let me just go forward, add another keyframe, and we'll add in a bounce. I don't think this is going to look all that realistic. Obviously, it's going too fast. But if I just give it the slightest little bounce right here where it is lifting off the ground just a little bit, even that doesn't really look all that realistic. How could we approach something like this? Well, one thing that's not very realistic about this is that it's staying perfectly horizontal; it's not rotating at all. Imagine if you were standing off of a balcony and you had a cinder block and you let go of it, it's not going to just stay in that exact same position. So let's introduce some rotation to this. I want to get rid of that bounce. We'll add in a rotation keyframe, Alt Shift R, and then go forward until just before it hits the ground, so one frame back, and let's just rotate this maybe like this, just a few degrees back. Now it's going to have a little bit more life to it because it's not perfectly falling to the ground. But what happens when it comes into contact with the ground? That's what we have to solve, that issue. Well, first of all, it needs to be level with the ground at this point, because even if we don't have the frames to cover the speed of how this would act in real life, I don't know if that made sense, but basically this could be happening so fast if it was real that 24 frames per second wouldn't be able to capture every single moment of what's happening. But what we need to do is put this square with the ground again. If I set that rotation to zero on this frame, then it's rotating and rotating, but then when it hits the ground, it's where it should be. I think that should be rotated 180 degrees, 180. Now it's facing the same direction until it slaps on the ground. We need that frame because we're animating this, we need to be able to see when it's on the ground. But maybe instead of just slamming there, what if it was traveling so fast and hit the ground hard enough at that angle that it now rotates up on its side and does 180? It rolls over. We can pull that off with another technique. I'm just going to rotate this back a little bit more so it looks a little bit more extreme. Actually, why don't we ease out of that rotation value as well? Let's get this up to 180. Now it's just easing out of there. I'm not going to do it perfectly horizontal, just so it's already moving when we first see it. Then let's talk about how it's going to rotate from this point. What I want to do is rotate it from this corner. But I can't do that because the anchor point is straight in the center, and I can't move my anchor point because that's going to modify my keyframes and mess with the animation I've already created. So I need a secondary control, and to do that, I'm going to use a null object. If you go up to Layer, New, Null Object, that's going to give us an empty layer that does not render, but it has all the same transform properties as any other layer. What I can do with this is zoom in nice and close to the bottom right corner of my cinder block and move this anchor point of this null right where I want this one to rotate. If I hold down Control or Command on a Mac, it's actually going to temporarily snap to my pads and I can put it right there on that corner. Now that anchor point is oriented where I want this to rotate from, and all I need to do is parent this cinder block layer, using the parent pick whip, to the null object. Now I can rotate that block off at that point. I'm going to rename this null object Rotation 1. We're going to set a rotation keyframe at that point in time at zero. Let's just clean this up. I want to press U to show all my keyframes, press U again to close that up, and then just select those two layers and press U so I can just focus on those keyframes. What I want to do is have this block stand up. I'll go forward maybe 1, 2, 3, 4 frames and then rotate it, this property right here, 90 degrees. Now it's standing up, slams into the ground, and then stands up. But I don't want to stop there. Now I want to rotate from this corner so that it tips over flap; has done a full 180. How do we do that? I need to make another null object. I'm just going to duplicate this Rotation 1. I'm going to bring up those keyframes that are already there and just scoot them over to this point, and then move the anchor point over to this side. Holding down Control or Command on a Mac to snap. Now I just need to parent this Rotation 1 to Rotation 2. The cinder block is parented to the Rotation 1, Rotation 1 is parented to Rotation 2, and now I'm going to get that full rotation on that cinder block. Let's play it back. It's not going to look right. We need to do a little bit of easing, but it's not bad. Just a couple of keyframes. We're getting the motion that we want, we just need to work on the timing of the keyframes. I want it to have a little bit of easing going into this rotation keyframe right here, so let's start there. I'm just going to ease into this a little bit. Maybe take some of the easing out of this keyframe so that it really pops up there. But really, you know what? Let me take that easing off real quick. What I want is for it to slow down a little bit right at this point because it's taking a lot of the energy out getting up to that tipping point, but then again gain speed to get here so that it continues to fall over. So I need to add another keyframe right in the middle and ease that one. Without even knowing it, I did just use the Pen tool to add a keyframe there. I just held down Control or Command on a Mac, you just click. I've been using the Pen tool to modify these keyframes in graphs this whole time without even really thinking about it. But what I want to do is add that keyframe right in the middle, hold Alt to ease it like this. Bring these handles, not a lot, not really strongly, because if I do that, it's going to really slow down and then really speed up. But I just want to very slightly angle this so that it loses some momentum, but then picks it up again on the other side. I think I could space these keyframes out a little bit more. I'm going to just add one frame at a time between keyframes to see how it modifies things. That's not bad, I don't think. I just need to work on the easing of these ones right here, which at this point it should be traveling pretty fast, and then really slam down into this value right right here, so it should be this shape. This is very subtle because of how quick of an animation it is, but making these subtle adjustments are things that viewers will really pick up on. Let's look at it as a whole and play it back. You can see how that just feels like it has a lot more weight than that tennis ball. It feels more realistic. That rotation, I bet I could even space that out a little bit more. I'm just going to do that real quick. What did I just press? It just feels a lot more accurate now, and it all has to do with modifying those value graph handles. But that's how you would approach animating something like a cinder block or something much heavier falling differently than you would a tennis ball. If I bring that tennis ball back on, these things are probably going to collide. Yeah, they are. But I could just shift over the exposition to this. No, I can't. I forgot about my parenting relationship. If I move this over, there we go. Now it's going to preserve that animation. You can see how those two very different animations feel no; they have much different weight. But we have one more example.
6. Animate a Falling Feather: Now we're going to go in the complete opposite direction and animate a feather, which is going to have a completely different look and feel than the previous two objects. How would you handle something that's virtually weightless falling? Where gravity is almost not a factor to it. Well, let's take a look. I'm going to turn off the cinder block and the tennis ball. Actually, let's keep this cinder block on. It might be fun if I have it land on a cinder block. I'm going to just move it right there. Let's say that the ground for this, let me clean up my timeline, [inaudible] , collapse everything and then select the feather and press "P". I can separate those dimensions and we're going to put the resting point right about there on the cinder block. This is where it's going to fall to. I set a keyframe. We'll go back to the first point right here. Actually, I'm going to move this all the way off the comp. Same thing for this cinder block. I'm going to grab that position, the y position value and just move it off. It's not just hovering there and suddenly gravity is working. Let's just think about this, so right now it's just floating down. Honestly, that's not too inaccurate. A feather is pretty much going to fall at a constant rate down to the ground. But it's never going to fall in a perfectly straight line like that. It's probably going to be rotating. It's going to be going back and forth just like that. Let's introduce some animation on the exposition. Then we'll add in some rotation in a little bit as well. At the top, it's fine, that it's right there, but let's just go forward a few frames and modify the exposition a little, go forward a little bit more, modify the exposition, go back, and then eventually land where we want it. Now we've got this zigzag pattern. How can we make that smoother though? Because right now if I play this back, it's not looking that great, it's bouncing back and forth like a screensaver. What I want to do is grab those key frames on the exposition and easy ease them. So F9 on the keyboard, then go into my graph editor. I almost always do that. I easy ease to start and then go straight in the graph editor because I never just want to easy ease all my keyframes. Since this is not visible at the start, I want to take the easing out of that keyframe, and you can see how that's modifying the motion path right up here. When I do this, you can see how easing out of that it's staying in more of a straight line before curving. But if I take the easing off, then it's going to already be arching out, reaching that keyframe right there. That's more of the motion that I want. Same thing for the last keyframe. I don't want it to really ease into that value. I want it to just stop moving because it's coming into contact with that cinder block. Let's play that back and that's looking a little bit better. I think we could make that a little bit more extreme of a motion. I'm just going to modify some of these values. Now it's moving back and forth a little bit more. What about the rotation? Well, let's add in a rotation keyframe, Alt Shift R or Option R on a Mac. I'll move that right to the beginning, and let's just rotate it. Actually, let's not have it perfectly horizontal to start, let's have it more this angle. Then we'll change directions a little bit. These do not need to line up. In fact, let me show you what happens when I line these up. We'll start there. I'm just having this follow the path, like the tip of the feather is pointing towards the direction it's moving. But let's have it end up maybe about this angle. Then I'll easy ease all these keyframes again and just play it. Because the rotation and exposition keyframes are happening at the exact same time, it's not all that interesting. This is a very subtle example, but when you modify all of your properties at the same time, it can create very boring animation. Another animation principle is called overlap, where you're staggering your movements and that brings a lot more life into it. If I make the rotation staggered, maybe four frames, 2, 3, 4 frames forward in time. So they're lagging behind the exposition value changes. Then we're going to get motion that's a lot more fluid. Obviously, the ending needs to still happen. That it needs to end at the same time. I'm actually going to get rid of this rotation keyframe, bring this one back. We don't need to ease into that value. But now those two motions are overlapped and it's just a more interesting looking motion, more fluid. I think the value change between here and here is too much. I'm just going to grab these and bring them down. Maybe even bring this one down a little bit more too. That's a lot better than where it started. But we can make this even a little bit more believable I think, if we modify the shape of the feather a little bit. If we go into the feather contents, just twirl that up and down again and then go into the contents. You'll see a group called paths. We want to go to the transform controls for that group. Going into that group and this scale property right here is what we want to modify. I'm going to just set a keyframe on a scale property and press "U". We get back to just looking at the keyframes and what I want is to unlink the x and y, the width and the height of our scale so that I can adjust just the y property. Let me hide my overlays so you can see what's happening here. Because my stroke and my filler applied outside of that group, we're maintaining that stroke width. That's why we're basically getting a fake 3D rotation of the feather. What I want to do is at the beginning, set a keyframe or leave a keyframe at 100 percent on that y value of the scale, and then go forward a few frames and change this to negative 100. I'll just type in negative 100. Now it's going to look like it rotated and then we'll just go back to 100, where we started. Now you can see how that looks like, it's rotating it as that falls down. I'm just going to duplicate these keyframes. Select them, copy and paste, and copy and paste one more time. We'll have it end right about there. Then I can just work on the timing of how quickly it's rotating, as well as easing out all of these keyframes. Let's go on the speed graph or the value graph. This is going to be a little interesting because I cannot separate dimensions of a scale property that's only for the position property for whatever reason. I'm going to be seeing both the x and y scale values at the same time, but the green graph is the y value. That's what I'm concerned with. But I'm going to select all the keyframes and easy ease them and then just look at how that's making it float down. It's very rare that I ever want to use easy ease, but honestly that doesn't look too bad. I think I might exaggerate it just a slight amount on each direction. Now it looks like that feather is just fluttering in the wind. Again, this is something that I could tweak all day long. I'm not going to make you sit through that, but you can completely customize the way that this is rotating and falling to the ground. Maybe these first three keyframes should be more down here. Maybe this one comes up a little instead of going down, it's pretty fun to just interactively be able to modify these values. Now that they're set, then they're all independent to come up with something that looks totally unique. Maybe you want the easing on that rotation, that four rotation that we made to be a lot more east, more extreme. That's totally fine. Maybe you want it to happen faster. I could scale this down. Grab these three keyframes and paste, and maybe paste one more time. Now it's going to be rotating even faster as it's falling. But the y position, we haven't looked at that yet, if you look at that graph, it's totally linear. This objects, even though we're still thinking about physics in reality. It's moving at a constant rate down to the ground and say that there was some wind blowing. These are all things that you can think about as you're creating your animations. If you needed to indicate that there was wind blowing, well then maybe, you'd want to add in a couple of more keyframes here, and just do that same trick where you slow down the motion a little bit. Just so it's not so perfectly linear the entire time. You do something like that. Now it's hanging at a couple of those points and it's not dropping at a constant rate. It's just something to play around with and get used to. But there we have this feather just gracefully falling, completely contrasting what's happening with the cinder block. Let's bring our friend the tennis ball back in and he goes behind the cinder block, but maybe we'll just drag them up. We've got three completely different objects all coming to rest together in a pile. That's a nice little scene. But that's how we can use all of these different techniques and thinking about timing, spacing, and the weight of the object and the environment to make something that is unique and playful, but still based in reality.
7. Q&A: Now, we're going to open it up and let people watching at home ask some questions. One question that did come through when you were animating the cinder block might need some clarity but see if you can answer this. Can we animate the anchor point of the first null object to the other point? That's a great question. The answer is no. But let me show you why. What this person is asking is, can we use one null for the multiple points of rotation? The reason why we can't, if I just get rid of these keyframes of the second. Actually, let me just delete for now, just delete that rotation too. We have the block hitting the ground and the first rotation null standing it up. The reason I can't move this over is because the block has parented to it, so if I try to move this null, the block is going to move with it. If I bring up the anchor point and try and move that, that still adjusts the cinder block which is parented to it because the cinder block is going to inherit every transformation you make to its parent. That's why the anchor point, the position, the scale, rotation, all of those things are going to manipulate that block. That is why you have to use multiple nulls. How do you gather inspiration to help your animations being more life like? Is it YouTube? What do you do? That's a great question. Honestly, the thing that I try to do the most is just think about the real world. I use my hands a lot. I don't know if that came on in camera when I was talking about the ball bouncing. But when you think about a ball bounce, I pretended that I was holding the ball and that my hand was the ball. That happens all the time when I'm thinking, how should this be moving? Like if it was a paper airplane that I threw through the air, I would try to in my mind think about how that airplane is going to be moving and how I want it to look in my design. It's really just a lot of creative thinking. But like I said, I use my hands a lot. I pretend like my hand is the object that is moving and I try to think of it in terms of real world motion. To find inspiration like if I needed to know how a bowling ball is going to bounce on concrete, I'm going to go to YouTube, because I'm sure somebody's done it. I want to see how it actually works in the real world. It's probably going to behave differently than I expected, so I'll probably modify it and take my creative liberties of exaggeration and having fun with my animation and just making it my own but, yeah, YouTube is a great resource. Just seeing how a bird flies or anything when you're trying to mimic real world motion, just Google it or go experience it in real life, look out a window or something like that. Another question, when to choose to animate in 30 frames per second? That's a great question. It's completely dependent on the project. If you're working on your own projects, if it's a personal project, then really it's a matter of taste. Twenty four frames per second looks different than 30 frames per second. If you like the look at 30 frames do it, if you like the really smooth motion, try animating at 60 frames per second. Formats. YouTube supports that type of format and it just looks super cool sometimes. But with that there is a render hit, obviously because you're having more frames. It's really usually dependent on if you're doing it for somebody else, what their specifications are but if you're choosing to do something for yourself, then it's a matter of taste. Which software have you used for the cube animation? That was actually in After Effects using a plugin called element 3D, from video copilot to make the 3D geometry. You can actually do 3D geometry directly in After Effects now. But to get this type of distortion with the twisting and the squashing, that was through element 3D, no plugin.
8. Final Thoughts: I just want to thank you so much for taking this class and one thing that I really don't want you to do after this session is to feel discouraged like this just went completely over your head. That's fine. This stuff was not something that I instinctively knew how to do. It's something I had to learn. You have to practice these things. One of the biggest suggestions I can give you is to study the real world. Like I was talking in the session, when you go outside, just pay attention to how things move. Look at how birds fly, how cars take off from a stoplight, things like that. Start to think about how things are moving so that you can begin to design the motion yourself. Eventually, you're going to get the hang of it and you're going to start to just inherently know how you should be animating things. Whatever you end up creating from this class, I would love to see it, so be sure to share it in the project gallery and if you want to share it on social media, absolutely tag me @jakeinmotion so I can see it, heart it, give it a like, maybe you can share it on my Instagram stories. I would love to see your work. If you're interested in what we talked about, I know that it was a quick class, but if you're interested in learning more in-depth things, like maybe you haven't really touched the graph editor yet, that can be a very confusing thing if you never really modified those curves before, you can check out another one of my classes called Animating with Ease, where I dedicated that entire class into the graph editor, both the speed and value graphs, how they work, how you can manipulate them, and get your motion to look exactly the way that you want them to. If you're interested in learning more about animation principles like squash and stretch, anticipation, overlap, all of those things that we touched on in this session, then check out another one of my classes called Animation Principles: Add Playful Personality to your Animations. I've dedicated the entire class to those topics and discuss them at length. If you really want to get into that world of animation principles, be sure to check out that class next. Thanks again for tuning in today. I'm so glad that you were part of this class. If you want to see more of my work and my classes, be sure to follow me here on Skillshare and check out my profile where I've organized all of my classes for you. That's it. I'll see you in the next class.
Jake Bartlett, Motion Designer
