Blender Keyframe Animation

A simple bouncing ball

Key frame animation is a relatively simple type of animation. The essential idea is that the user sets a series of guiding points and times between these guide points and then the program calculates how the object will move between these points. This can be a good basis for animation for an individual object that has no other objects as children. It is less elegant than path animation for the movement of objects because it requires the definition of more reference points (the key frames) in order to define movement. For actions on individual objects such as rotation and scale it is the only option for animation. The extension and interpolation can still be defined in the IPO editor.[1]

A Simple Key Frame Animation: Bouncing Ball

  • I

First we must set up the scene. When you open blender as always you will have a box in the center of the screen. Press x to delete the box. Right click on the camera and delete it. Do the same to delete the light source. Now press 7 to enter top view. Then press spacebar add->mesh->plane. Now press S to resize the plane so it fits into four of the large gird squares. Now switch to front view by pressing 1. Then press spacebar add->camera. Grab the camera and constrain it to the y-axis g y and drag it so that it is two boxes away from the edge of the plane. Now grab and constrain to the z-axis g z and move the camera so that its bottom dotted line sits on the closest edge of the plane you created. Go back into top view 7 and hit spacebar add->lamp->lamp then move this lamp to either the right or left corner of the screen. This will give you a basic scene. If you want more on lighting follow this link.

  • II

Now we will add a ball. Click spacebar add->mesh->uvsphere and accept defaults. Now go into camera view 0 and grab and constrain to the z-axis and align the top of the ball to the top dotted edge of the camera view.

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  • III
    • a Now we will add key frame style movement to the ball. With the ball selected press i to insert a location key frame. Now press the up arrow you will see the number of key frames increase on the bottom of the screen
      51 represents the number of frames
      . Go up to 75 key frames so that the ball has a smooth 3 second bounce. The default ratio of frames to time is 25 frames per second. Now press g z to constrain the movement of the ball to the z-axis and drag the ball until its bottom edge begins to disappear under the plane. Now insert a location key frame.
      Caption text

    • b As in the path animation tutorial we will enter the IPO curve editor. This can be gone through the menu selector in upper left hand corner of the lower window. Here you will see a yellow down sloping line select it. This line indicates the movement of your object through time.
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      Right now the ball only goes down so we want to make it rebound. Tab into edit mode the control+left-click on around 150. The yellow line will now look like this. Tab back into object mode and go to curve window->extend mode->cyclic extrapolation. Now the IPO curve looks like this.
      Caption text

  • IV
    • a Now we will deform the ball on impact with the ground. Up-arrow to frame 65 then press i insert key frame->scale. Now up-arrow to key frame 75. These are the frames where the ball begins to disappear under the plane to its apex of invisibility. Now press s z to scale constrained to the z-axis and deform the ball so that the white line which marks its periphery is in no place under the plane. It should look like this.
      Caption text
      Now Go to key 85 and rescale the object to the previous values and insert a scale keyframe.
    • b Now go back to the IPO editor tab into edit mode and select the three points that makeup the object scaling they will be peach colored and should sit near the yellow z-axis line.
      The scale lines.
      Press shift+d to duplicate the lines and then g x to constrain movement to the x-axis then align these three points to the trough of the next yellow line. Repeat this task for as many times as desired. Now press alt+a to see what the ball movement will look like. There is also a rotation option. The essentials of this are the same as these other two key frames but what you can do is different.
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