Transcripts
1. Intro: Hi, I'm Hongshu and I'm a motion designer in Canada. I have been animating for six years now, working in an advertising agency, it's for clients like Adidas, PayPal, Walmart, and many more. Today, I'll teach you one of the animation basics, something that you have to know if you want to become a professional animator, which is a realistic ball bounce. Once you grasp the foundation of the bounces, you can actually apply it to any objects in your scene to add character to your animation. In this class, I'll first explain to you the concepts of a ball bounce. How different weights of the ball can affect the balance and the rules we need to pay attention to. Then we'll open "After Effects" and start animating. I'll demonstrate to you with two types of balls. One is a smaller, lighter ball, and the other one is a much heavier ball. I will show you how to animate based on material and weight to get the realistic look, how to use the value graph in the Graph Editor to control the bounces. After that, we'll be animating a ball bounce in a more complex scene, I'll show you how to animate the ball to interact with the object in the scene and still make it look realistic. At the end, I'll also include an assignment for you to practice these things we learned in this course, a completely new bouncing scene where you can apply the techniques. Don't forget to upload your assignment to the project page to share with me and get feedbacks. This class is for someone who already has some experience with After Effects and are familiar with the software itself. If you're just getting started with motion graphics, I recommend you to check out some of my other beginner classes to get to know the software better before you take this one. The techniques we taught in this course can be applied to all kinds of objects in your animation. Once you understand how to animate the basics, you will find an infinite option to make things bounce. Without further ado, I'll see you in the class.
2. Ball Bounce Explained: Today we'll be learning how to do a ball bounce. The general consensus at if you really want to be a real animator, you will need to learn how to do a ball bounce, which I found is quite accurate because there's so many scenarios where you need this technique, the ball bounce technique to animate objects. That's why we're here today. In this lesson, I want to show you how the ball bounce works. Then I'm going to show you how to animate it in After Effects in the next video. I guess a bigger question here is something that I want you to always remember as an animator, which is, you need to think about what is making the things move. What are the forces that's acting on the object, and how to translate that force into animation. When we're thinking about ball bounce, I think the main force that's acting on the ball is going to be gravity. Gravity is pulling the ball down. Then every time the ball hit the ground, it's going to lose some of the energy. Then it's going to bounce, bounce, bounce until it stops on the ground. Let's say for example, this ball we have here. This is going to be a normal ball like what is a normal ball? It's going to be something that's not too heavy and not too light, not too bouncy, maybe a golf ball. Then I have a ball here. If it falls, it's going to fall like this. Hit the ground and then bounce one time, and then bounce another time. This slightly is going to lose some energy, slightly like this, and then just stop on the ground. This is going to meet our general bounce for a normal ball. Two things that I want you to remember or two most important thing for a ball bounce, first is that when the ball falls, it's going to lose energy. That's why you see the ball hit the ground and then the ball is going to balance lower and then lower each time until the final stop on the floor. The second thing is that the angle that the ball is hitting the ground, the angle is the same angle that the ball is leaving the ground. If I draw a center line here, in the center, this angle is going to be the same as this angle here. If I draw a line here in the center, or even in each of these touching points, excuse my bad drawing, but technically speaking, this angle is going to be the same as this angle. Then this angle is going to be the same as this angle. The angle that the ball is hitting the ground is the same angle that the ball is leaving the ground. That's the second important thing I want you to remember. We're good with this example, now let's go to the second example, which is going to be a heavy ball. Let's draw maybe a bigger ball here, heavier ball. When this heavy ball falls, it's going to fall to a curve, something like this, fall on the ground. Something like this, it's going to fall on the ground. Then it's going to probably bounce, and then bounce like this. If you think about a bowling ball, that's how a bowling ball is going to fall. It's going to probably jump one time a bit higher, and then a couple more times really really low, barely leaving the ground, and then until it stops on the ground. That's a bowling ball bounce. Third, we have a light bouncy ball. This one may be like a small bouncy ball. If this ball is bouncy, so when it drop on the ground, it's going to bounce even higher. Each time, although it's going to lose some of the energy, but it won't lose as much energy as the previous two balls, something like this. This ball is going to jump, jump, jump, jump, jump. Excuse my bad drawing. But I just want to try to convey the idea. This one, to be honest, it's not very accurate because one, the ball bounces, hits the ground. Instead of a straight line for each touchpoint of these curves, instead of them forming a straight line, it should form something like a decay curve, like this. It looks to me that my curve here, the graph here, it looks like a straight line. But it shouldn't be a straight line, it should be a decay curve like this. If I draw a line here, this is my decay curve here. Decay curve. Then if I draw the ball bounce here on this smaller graph, it should look something similar to this. Each time it's just going to lose some of the energy until it settles. It's not going to be exactly same as this decay curve. It just, generally speaking, it won't form a straight line, it should be a decay curve like this. Those are three of the examples I want to show you today in this lesson. This is going to be a bouncy light ball and then we have a heavier bowling ball, and then just a normal, regular ball. That's it with this lesson, next video, I'm going to show you how to do this in After Effects.
3. Animate Ball Bounce : In this lesson, I'm going to show you how to animate a ball bounce in After Effects. As you can see, I have here already scene setup and then I've got this small ball here in the center, the yellow one, and then this bigger ball which looks heavier. Today I just want to show you how to animate these two ball bounce. First of all, I need to put the anchor point in the center of the ball. Just want to put it in the center like that. Then this ball here, I want to put this anchor point in the center of the ball. First of all, let's animate this small ball here. This is going to be the ground. Let's use a line to mark where the ground is so that we're not going over into the ground. Go to position property P, and then right-click "Separate Dimensions". The ball, we're only going to be animating on the Y position first for the bounce, let's set a keyframe on the Y position. Go for 15 frames, 10, 1, 2, 3, 4, 5, 15 frames and drag these keyframes onto the 15 frames mark, and then go back to zero seconds, lift this ball up. I can let it just drop from outside like that. Now what I want do is, I want the ball to maybe bounce every 10 frames, let's say, go forward 10 frames. The ball is going to still be on the ground. Each time it's just going to hit the ground, so 10 frames on the ground, 10 frames just copy this key frame, and copy this key frame. I set a keyframe every 10 frames, but the ball is not moving its position because it's always hitting the ground, and then let's select all of them. Keyframe assistant, easy ease, go to the graph editor. First of all, let's make sure we're in the value graph, not the speed graph and then we're only working on the Y position. If you think about it when the ball drops it's going to accelerate. This curve here, this handle here should be something like this. The ball from top, it's going to go, remember steepness equals speed in the value graph. The curve is going to be steeper and steeper, which means the speed of the object is moving faster and faster, so that's what happens when something drops from top. It's going to go faster until it hit the ground and lose some of the energy. Remember in the previous lesson, I told you that each time it hit the ground, the angle when it hits the ground is the same angle when it leaves the ground. What we need to do is here, we need to drag this angle. This angle here need to be same as this angle when it hits the ground. I want to try to do something like this, same angle, so just drag this. Then it's also going to lose some of the energy. Which means each time when it hits the ground, it's going to jump lower and lower. I just want to create a curve, something like this and then I need more keyframes. I want to copy, "Command C" and then go forward 10 frames, "Command V", add a keyframe and just modify this curve here to make this curve more subtle and go forward 10 frames, copy and paste in other keyframes. I want to zoom in, make this curve very subtle. Although the curve is not as aggressive, it's very subtle. I still want to make sure that the angle that's going into this point here, it's the same angle that's leaving this point. Here I want to make sure the angle is right, and also the ball is losing energy. If I fit graph to view, this is what it looks like. Now let's preview and see what happens. This ball right now, it feels a bit heavy to me. The second jump is too low. I want to modify just the second one. This one here, this curve here is too different from this one here. I want to modify it and just to give it a higher peak here so that it's similar to this one and I just want to make sure it doesn't look so heavy because we have another heavy ball for the second demonstration. I want this ball to be not so heavy. I want it to be a little bit more bouncy. Like if you want to make it very bouncy, you can make these curves so high. Then each one, you can just have it loose a little bit of the energy so each curve is still very high. In that case, the ball is going to be super bouncy. Let's preview it again. See what happens. You see. Drop, drop, drop. I feel like the timing is a bit off. I need to just drag all of the keyframes to the left so that the whole thing is happening much faster, in two seconds. So there you go. This is your ball bounce curve, something similar to this one. Next one, I want to do this. I can hide this small ball and then just click on this big one. Put the big one on the ground, go back to zero second, and hit P on the keyboard. Strict click separate dimensions, add a keyframe. I want the keyframes be the same as in the previous small ball. I just keep duplicating. First of all, I want to go back to zero second and then let the ball just maybe fall from above. Then when it falls, Command C, Command V, I'm just going to copy this y position. Maybe paste it four time, because I don't think it's going to have the same number of bounces as previous ball because this one is too heavy, and then just select them all. Right-click keyframe assistant, easy ease. Go back to the graph editor. The same thing. The ball is going to speed up from the start, and then the curve is going to be something like this. In this case here, by the way, if somehow your handles is joined together, like when you move one of them, the other one moves as well. Remember this is C, convert. Select a keyframe to auto bezier. Once you click this one, these two handles it's going to be joined together, so you wouldn't be able to adjust them separately. In that case, it's hard to manipulate them to a curve as a bouncing curve. All you need to do, is just hold down Option on the Mac or Alt on PC. Then your mouse cursor change to a two-line arrow. Then that's when you can just drag the other handle and break them. Another way is to just click on one of those icons here to break the handle. Right now we're just animating this heavier ball here. I want the energy to lose super quickly. Now, let's preview this. Still a bit bouncy, it's still not heavy enough. Let's take a look again. It still feels a bit bouncy to me. Another mistake that I made just now is, right now you can see the timing of these keyframes are the same. However, it shouldn't take the same amount of time for it to balance for every single balance because the ball is losing energy, each balance is going to take less time to complete. That's why I need to move these keyframes closer and closer to each other at the backend, and I still feel like the first bounce is too high. I just want to make it even lower, and then use that on the keyboard to zoom in, get closer to be more precise with the curves. Let's try and see if that works. Yeah, that feels pretty heavy to me. The ball feels already very heavy. Yeah. It feels like a metal ball. This is going to be the curve that we have for a heavy ball. Then let's go back to this small ball to adjust some of this timing at the back-end because it's not going to take the same amount of time for each balance at the back-end to happen because it has has already lose some of the energy, right? I need to just grab all these keyframes at the back and then just make them closer to each other. It's going to take less and less time for the balance to happen. All I need to do is just bring the keyframes together. If I go to the keyframe bill, you can see it's further apart at the beginning and then slowly they're just coming closer to each other. Let's preview this small ball here. I feel like the first frame is too far away from the second frame, so I need to move everything closer to each other. Then I'm trying to drag this curve out, something like that, so that the first bounce happens sooner. Yeah, something like that. The next thing I want to do is just add a X position to this ball bounce. First, I'm going to move this to the left here, add a keyframe. Then maybe when it stops, I'm going to drag this X position. You can see all of a sudden we have all of these curves. What does that look like? Do you remember this? Is this something that I drew from the previous lesson? The ball would just drops, drops, drops, drops. This is a perfect example of a ball bounce. Let's preview this. Look at that. That's my first ball, and then if I have my second ball here, go to the front. I'm just going to adjust the X position. Set a keyframe there, and then go to the end. Drag this all the way to the right. Set a keyframe there. Let's see. Another ball bounce. Next. All we need to do is just to add a rotation. Shift R put a rotation at the zero second and then maybe 16 degrees. Let's see. I need to rotate, and more. I feel the ball is sliding, so I want to move back the exposition and then let's preview again. All right, there you go. That's your ball bounce animation. You can add a rotation value to the small ball as well. It's going to be essentially the same thing as this big one. Now you can already feel the material that this ball is made of is pretty heavy.[ MUSIC]
4. Complex Ball Bounce: In the last video, we talked about how to animate a ball bounce in After Effects, and this is what we get from the last video. In this video, I'm going to show you how to animate a more complex ball bounce. Let's go to the other composition that I have here. Here we go. We have the same scene here. However, let me show you what is the animation that we're trying to achieve here in this lesson. Now you can see my ball is actually interacting with those boxes here. It hit one place and then hit another place, and then it goes up to this stair thing, and then it hit this wall and bounce back. It's pretty realistic, so in this lesson, I'm going to show you how to animate this in After Effects. If I select all these keyframes here, you can see there's motion paths to this animation and then it resembles to the ball bounce curve that I showed you in the previous class. It's the ball itself is losing energy after each bounce, and also the angle when the ball hit the ground is the same angle as the ball leaves the ground. Those are the two general rules that we need to follow when we animate. Anyways I want to delete the keyframes now and then show you how to do it. Now we have this ball, strike the ball over here into the scene. First I want to pull a ruler down so that I know where is the ground. This is going to be my ground here, and first what I want to do is I want to animate the Y position first as a general bounce. I don't want to animate X and Y at the same time, because that case, if you're just started is going to confuse you because there's so many things that you need to consider. To make things easier, let's just animate the Y position first as a ball bounce straight up and down ball bounce. First of all, let's add a keyframe here at zero second on the Y position. So we'll go for 15 frames: 1, 2, 3, 4, 5. Drag this keyframe to the 15th frame mark, and then go back to zero second. Now I can just pull this Y position. Pull the ball outside of the frame so that the ball is dropping from the top like that, and then another 15 frames: 1, 2, 3, 4, 5. I just want to copy this Y position again because after one bounce, the ball is going to hit the ground again. Command-C, Command-V, and then maybe another 15 frames: 1, 2, 3, 4, 5. Command-D. So right now the Y position is not changing. It has the same value: 1, 2, 3, 4, 5, Command-V. Let's right-click "Keyframe Assistant", "Easy Ease", and then let's go into the Graph Editor. Make sure you're in the value graph instead of the speed graph, fit the graph to view with this button here. Now I just want to change this curve to be a bounce curve. Remember we had this ball bounce here, and then if we go into the graph editor, and then pull up the Y position. A ball balance is going to be like this. I want to transfer this curve into this ball bounce that I have here. The ball is going to fall from the top, and then I just want to pull these handles, make sure the angle going into the ground is the same angle as leaving the ground, and maybe I want to add one more 15 frames: 1, 2, 3, 4, 5, and then hold down Command on the keyboard, mouse left-click, "Add a Keyframe". Just slightly adjust this handle here, because in the last one the energy is losing and there's not much energy at the end, so I want the curve to be more gentle, very gentle. Now you can see this is going to be my ball bounce animation. Let's preview and see what it looks like. I feel like the third curve here is too low. I wanted to pull this up a little bit more making sure we'll still have the energy for the latter part of the bounce. Let's preview this. Yeah, that looks better to me, and now what's going to happen is I'm going to add in the X position change. In order for the ball to hit this box first and then hit this circular stage, second I need the ball to come from the left as if someone throw the ball into the scene, so I need a X position value change. Now since when I hit the X position, my Y position value graph is not in this graphic panel anymore. However, I need to see this Y position in this graph editor in order to know what's happening. In order to do that, we have this icon here. If we hit this icon, the Y position graph is always going to show in this graph editor. Although we're in the X position graph, this Y position graph is always going to be in this graph editor. This way, I can use this Y position as a reference and then I can animate the X position. Now what I want to do is just to drag this ball. Right now if I just change the X position, you can see the ball is moving to the left. I want this ball to move all the way to the left outside of the frame and then add a keyframe there, and then around the two second mark, I want to drag this X position out. Now you can see there's a bouncing curve. It's going to show me what's happening right now. I just want to drag it all the way out. Something like this. Now when I look at this curve here, I want to make sure the ball when it comes down following this motion path, it's going to hit this box first, and somehow it's going to hit the stage second, and the energy, the momentum is still going to carry the ball over to hit onto this stage here, this box here. When I look at the curve right now, it does what I want it because the curve right now is going to bring the ball up to this stage here; however, the latter part of the motion path is not going to work because the ball is going to hit this part and then hit on this wall here and bounce back instead of keep going forward. In that case, we need to animate and change the Y position. What I want to do here is just drag the timeline indicator and then try to figure out when the ball hit this box; at which frame the ball hit that box there. Around here. If I just drag it one more frame, it goes over to the bottom, so I need to just make sure the ball is going to hit the box at this frame here. I want to add a keyframe on the Y position, hold down "Command" on the keyboard and then left-click on this Y position value graph. Now I can delete this graph because the ball is not going to go down anymore, it's going to bounce up, so I need the bounce to happen at this frame here instead of the frame after it. I need to delete this frame. Hit "Delete" on the keyboard. Now I want to just slightly adjust this keyframe to make sure it touches that box. Let me zoom in. I'm just dragging this up and down to manipulate the Y position. Right now, I want to make sure it hit that box. Then what happens is the ball is going to bounce on that point. That's why I need to drag this handle. However, right now, the two handle is connected together. When I change one handle, the other handle changes as well. That's not what I want, so I need to break the handle. To break the handle, I can select this icon here. Hit on that, and then it's going to break the handle. Now, visually, we can see the ball just after it hit the box, it's going to bounce up. That's what we want. Then we just want the ball to just keep going forward. Hit the stage. That's what I want. Then maybe I want this curve to go even higher. Let's try to make this curve here in the graph editor higher. Just drag it higher so that there's still a lot of energy carrying the ball to hit on this box over here. If I make this curve higher, I better make this curve even higher because I don't want these two curves seem too similar, which means the energy is not losing enough, and that makes it unnatural, unrealistic. Still making sure the angle is the same. Then just hit that. The energy is going to carry the ball over to this box here. I just want to find that point where the ball touches that box. Over there. However, I think it's too much to the right. I need the X position to come over to the left a bit more, so that's why I want to change, at this point, the two-second mark. I want to change the X position to the left a bit more to give the ball more room on this box. You see? Instead of hitting almost at the corner there, I want the ball to hit more to the left. That's when the ball hits. I want to add a keyframe over here on the Y position. Hold down "Command" on the keyboard, Left-click, add a keyframe, and now we can delete this keyframe here. The keyframe after it, we don't need that anymore. Now the ball is going to bounce up again. Remember I told you how to change the handle. To break up the handle, use this icon over here. Another way is you can hold down "Option" key on the keyboard or "Alt" on the PC. You see that cursor has changed to this arrow here. Now once you drag the handle, it's going to break that handle for you, I just want to make sure when it bounces like that, it's going to have less energy than the previous bounce. Maybe something like that. I still want to try to maintain the same angle here. Now, when it bounced onto that wall over there, that's where it hits. At that second, the X position is going to change. The ball is going to change its direction, coming to the left-hand side. Now I need to add a keyframe on the X position. Hold down "Command" on the keyboard and then add a keyframe on the X position. Now I need to drag this X position down to make sure the rest of the motion is going to a different, opposite direction. Now, since the whole animation lasted for three seconds, I need to drag this final keyframe on the X position to the three-second mark. However, right now, I feel like there's not enough energy, so the ball hit that wall. I need the ball to bounce up a bit more. Right now, you can see the curve, it just goes straight down. That's not what I want. What I want is, I want this ball to bounce up a bit more. Something like that. Then I feel like the X position right now is messing this up because right now I need to make the ball to come even further to the left. If the ball goes this way, it makes more sense for the ball to travel further to the left. That's what we have so far, I think it looks good. There's one more thing we need to fix because remember, like I said in the previous video, when the ball loses energy in the back end of the animation, it's not going to take as long as a front end, which means all of these keyframes is going to get closer and closer to each other when it comes to the end. But right now when I started, I only put 15 frames apart from each keyframe so that all these keyframe right now, they have the same timing between each other, which doesn't make sense in real life. We need to bring some of these keyframes closer to each other at the end and just to try to make it more realistic. In order to do that, maybe from here, I need to bring these keyframes closer. Now I don't have enough height for this bounce here, so that's the case I need to drag it up. I feel like I don't have enough exposition in there anymore. I need to just maybe drag the ball even closer to the left so that after the bounce, the ball is still traveling to the left like that and then hit the ground. Then I need to bring this bounce closer. Let me zoom in. I want to see how many frames we have here, 1, 2, 3, 4, 5, 6. That's six frames. I want this bounce to be a bit more noticeable, so I still like to have a little bounce on the ground that's six frames and then 1, 2, 3, 4, I want to add a bounce at four frames, and then 1, 2, 3 maybe add a bounce at three frames and then 1, maybe add a last final slide bounce at two frames so that it ends at this point here. Its going to end at the same time as the UX position. Now I need to just grab these handles. Give it a bit more bounce to make it very natural. Okay. Let's see what we have now. Yeah, that looks much better. Let me deselect and see it more clearly. Now we haven't add any rotation to the ball. We can just add some of the rotation so it looks more realistic. But you can tell all of a sudden the bouncing at the end part, it looks much more promising. Let's bring our rotation value here, shift R and then add a keyframe at 0 second. Let's try to put one full rotation before it hit the wall and then after hit the wall, I want it to rotate in the other direction. Maybe negative, so it's still 0, but then I want to add in maybe negative 270. Let's see what it looks like. I feel like the ball is rotating too much. Right now, I need to bring the first rotation down, maybe to 240 something and then bring this one up. Another thing is the last keyframe of the rotation, if I bring this rotation keyframe back, maybe two frames, so that the rotation and earlier than the other two keyframes, the other position keyframes, it's going to give you an illusion that the ball is going to slide into the final position because there's no energy for it to rotate anymore. It gives it a more realistic feeling. Let's see what it looks like now after the changes. I think what I want to do is I want to extend the keyframe on the X position, maybe for two frames, to give an illusion that the ball is also sliding. I want to add a keyframe and then drag this one down. I don't want to change this keyframe, drag it to the right because it's going to mess up some of my keyframe in the front. If I add a keyframe and then let the ball just keep traveling further, it's not going to change anything that I animated previously. Let's take a look and see what it looks like. Yeah, I like that, so that's a stop is more smooth, it's not so abrupt. Then although the ball is rotating at the beginning, it looks to me that at the end it doesn't have enough energy to rotate anymore, so it just slide on the ground until it comes to stop. There you go that's how you do a more complex ball bounce. After this lesson, you should have full control of your object in some of the scenarios you're going to encounter when you do the animation. Now you can just fully control your object and do whatever you like.
5. Ball Bounce Assignment : In the last video, I showed you how to animate a ball bounce with both heavier balls and lighter balls, and I also showed you an example of how to animate a complex ball bounce. If you're not super clear on how to do that, you can still go back and watch that lesson again. In this assignment, I've got a composition setup for you already. Here we have an Assignment 4: ball bounce. Basically what you need to do is to animate this ball here in the scene to drop from the top and maybe just land on those boxes and I've got all these boxes separated for you so that you can move them around, if you want them to interact with the ball. If you don't want to interact with the boxes, you can just let the ball drop from the top and then hit the ground to practice some of the bouncing animation. Whatever way you want to choose to animate, this is going to be a great exercise for you to get familiar with a ball bounce animation, and it's something that you're going to need in the future for professional projects. In this assignment, all I want you to do is to have some fun with this scene here and I can't wait to see what you come up with. Good luck with this assignment.
6. Congrats: Congrats on finishing this course. Now, you should know how to easily make a ball bounce or rather make anything balance however you like. Don't forget to work on the assignment and upload it to the Project page. The more you practice, the better you will become. You can also check out my other classes on animation. Thank you so much for taking this course. I'll see you next time.
Hongshu Guo, Motion Designer
