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Current time:0:00Total duration:3:16

Video transcript

okay straight ahead animation works but a lot of times it's hard to figure out where you're going a lot of times it's helpful to start by working out what we call the key poses first for a bouncing ball that's going to be where the ball is at its highest point and where hits the ground I'll start by drawing frame 1 up high now let's draw frame 9 on the ground now I can draw the in-betweens using these key poses as a guide I'll draw frame 5 in the middle we call this a breakdown now I can keep adding more frames subdividing the space sometimes it helps to make a little chart to keep track of all the numbers great now let's shoot our drawings and plan back in fact we can cheat and make it bounce back by reusing the same drawings on the way back up hmm the ball is moving but it's not very realistic sometimes before you get started it helps to shoot video reference so you have some idea what you're doing remember the ball needs to speed up as it falls to the ground our frame five is halfway through the animation in time but the ball shouldn't be halfway to the ground at that point instead I'm going to draw a new frame five that's biased towards the first pose maybe I'll draw out a third of the way down animators have developed a visual language using these timing charts to show how to space the drawings in-between key poses so frame five remember is a third of the way between one and nine I'll draw frame three a third of the way between one and five and so on these charts help us keep track of the in-between drawings so we end up with the proper timing when we play this back the ball accelerates towards the ground now let's see how we use the same technique opposed to pose animation on the computer we'll start by positioning the ball up in the air on frame 1 just like before and then we'll skip ahead to frame 9 and put the ball on the ground down below the picture the computer shows us this graph it's kind of like the 2d timing chart and it shows us how the computer is going to calculate the in-between frames the horizontal axis is time and the vertical axis is how high up the ball is check this out if we project the intersection of each frame onto the vertical axis we end up with exactly the same timing chart that the 2d animators use you can see that by default the computer connects our poses with a straight line in the graph this is called linear interpolation it results in even spacing of the poses when we play it back the ball will move at a constant rate now you give it a try see if you can animate a convincing bouncing ball using linear interpolation and here's a hint you can add extra keyframes in between to get the spacing that you want