Keyframing

12 Oct

Keyframing

Manual Keyframing

A keyframe can be recorded manually by either using the Animate menu’s Record Active Objects command, clicking on the Key icon (Record button) in the Animation Palette or by pressing Cmd/Ctrl + F9 on your keyboard. This will create a keyframe at the current frame for the following filter parameter(s) Position, Scale, Rotation and Point Level Animation (Punkt Level Animation), which can be activated or deactivated individually. These filter parameters can also be found in the Animation Palette and can be activated and/or deactivated when creating an animation.

Next to most of the parameters in the Attribute Manager  you will find a small empty circle. This means that each of these parameters can be animated. You can set a keyframe for such a parameter by Ctrl[Cmd + clicking on it. This will turn the circle to a red dot to show that a keyframe has been created for this parameter at this frame.

Keyframe can be deleted by Shift + clicking on the red dot. This action deletes a keyframe but not the Track to which it belongs. To delete all information for a specific parameter from the Timeline, Ctrl+Shift+click on the parameter’s circle.

Colour Coding for keyframed parameter dots:

  • A red dot: A keyframe exists at this frame for this parameter.
  • A red circle: This parameter has been animated but no keyframe has beed set at this frame.
  • An orange dot: A keyframe has been set for this parameter at this frame but the parameter’s value has been changed and no new keyframe has been set.
  • An orange circle: A keyframe has been defined for this parameter but not at the current frame, and the parameter’s value has been modified without a new keyframe being set.

Autokeyframing

Autokeying works similarly only that you do not have to click on the Record button. Each time you change an activated value the keyframe will be automatically modified accordingly. Automatic Keyframing should, however, be used carefully since object parameters can easily be animated inadvertantly. If this mode is enabled, a red frame will be placed around the Viewport window and animatable parameters will be displayed with a different text color.

The Timeline

The Timeline is where you will do most of your animation work. It offers the most control over your animation as and also lets you interpolate keyframes. The Timeline has three modes: Key Mode, F-Curve Mode and Motion Mode.

Key mode

Key mode is used for basic work with keyframes and offers the best overview of your animation. Keyframes can be added, moved, scaled, copied, pasted, duplicated and more. If you want to adjust certain parameters an F-Curve can be displayed under each Track.

The F-Curve mode

The f-curve mode can be used to edit the interpolation of individual keyframes. Before a Track’s F-Curve can be displayed the F-Curve must be selected in the Object area (if you select a parent Track all subordinate Tracks will be displayed simultaneously). If a keyframe is selected, handles will appear with which you can modify the shape of the selected interpolation.

The Motion Mode

The motion mode system allows animation sequences to be easily repeated, mixed or transitioned. This mode is used when Motion Clips are added and modified.

Timing and Interpolation

Timing

A sequence of frames represents a specific span of time.Traditionally animation has been done in 24 Frames per second (FPS)

Depending on the output format used, the number of frames per second will vary. For example, the NTSC format requires 30 FPS of animation and the PAL format requires 25 frames per second of animation.

To avoid having a different FPS for output than you do for your Viewport animation, make sure the FPS in the Project Settings… matches the frames per second in the Edit Render Settings… Output tab. To define a frame rate, open the Render Settings menu (Ctrl[Cmd+b) and change the FPS value in the Output tab’s settings. To change the frame rate in the Timeline select the Document command from the Attribute Manager…’s Mode menu.

Interpolation

A single keyframe contains the parameter values of the current frame. What occurs between two frames that contain different parameters is an interpolation of the modified values, e.g. acceleration, deceleration, increase or decreas in size, etc. Values that do not change from one keyframe to the next will be interpolated accordingly. The Interpolation is important in that it helps create a smooth animation, which also keeps the animaiton from looking too “mechanical”.

The Interpolation differs from the Frame Rate in that the spatial positioning of the keyframes is of importance. Interpolation makes it possible to control the velocity of an animated object between keyframes. With it you can define the time interval with regard to the distance the object moves. This correlation, as you can see in F-Curve mode, is very important for creating spatial movement.

Types of interpolation

  • Spline Interpolation
    • This automatically creates a soft transition from keyframe to keyframe with a slight subsiding of motion in close proximity of the keyframe itself. This results in an organic movement without much effort and is therefore defined as the default method of interpolation. The F-Curve for this type of Interpolation is displayed as a soft curve whose keyframes each have a handle that can be used to adjust the radius of the curve.
  • Linear Interpolation
    • Creates a simple, direct transition between keyframes. The keyframes are not assigned handles, which means the movement between keyframes remains linear, with a consistant velocity. This type of Interpolation is useful when the position between two identical keyframe values should be maintained.
  • Step
    • With it, an object maintains its current value until the next keyframe is reached. This mode is very useful when creating on/off animations or for determining an object’s starting position or timing.
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