How to Create and Interpolate Keyframes in Blender

Keyframe animation is the foundation of motion in 3D space. This guide provides a direct, step-by-step walkthrough on how to insert keyframes in the Blender timeline and how to use interpolation modes to control the speed and transition style of your animations.

Creating Keyframes in Blender

To animate any property in Blender, you must record its value at specific points in time using keyframes.

1. Set the Playhead: In the Timeline (usually located at the bottom of the default workspace), drag the blue playhead to the frame where you want the animation to start.
2. Position Your Object: Select your object in the 3D Viewport and transform it (move, rotate, or scale) to your desired starting state.
3. Insert the Keyframe:
   • Hover your mouse over the 3D Viewport and press the I key on your keyboard.
   • Select the channels you want to keyframe from the menu (such as Location, Rotation, or Scale).
4. Create a Second Keyframe: Move the playhead to a later frame, change the object’s position, and press I again to insert another keyframe. Blender will automatically calculate the movement between these two points.

Alternative Method (Auto-Keying): Click the red Record button (a solid circle) in the Timeline header. Once active, any transform changes you make to your object on different frames will automatically generate keyframes.

Managing Keyframes in the Timeline

Once keyframes are created, they appear as yellow diamonds (or orange when selected) on the Timeline.

• Select: Left-click a keyframe to select it, or press A to select all.
• Move: Press G and drag your mouse to slide keyframes to different frames, altering the timing of the animation.
• Duplicate: Press Shift + D to duplicate selected keyframes.
• Delete: Select keyframes and press X or Delete.

Interpolating Keyframes (Changing Motion Curves)

Interpolation determines how Blender transitions between your keyframes. By default, Blender uses a smooth Bezier curve, but you can change this to suit your animation style.

To change the interpolation mode:

1. Select the keyframes you want to modify in the Timeline.
2. Press the T key on your keyboard.
3. Choose one of the three primary interpolation types from the pop-up menu:

• Bezier (Default): Creates a smooth transition with “ease-in” and “ease-out” effects. The animation starts slowly, speeds up in the middle, and slows down to a stop.
• Linear: Creates a constant, uniform speed between keyframes. This is ideal for mechanical movements, background loops, or cameras moving at a steady pace.
• Constant: Holds the value of the first keyframe until the playhead reaches the next keyframe, creating an instantaneous jump. This is perfect for blocking out animations or creating stop-motion effects.

For advanced control over these curves, switch to the Graph Editor workspace, where you can manually adjust the handles of individual Bezier curves.