How do I change all keyframes in Blender?

To change all keyframes in Blender, use the Graph Editor or Dope Sheet editor to select and manipulate them. Here's how:

1. Select Your Object:

Ensure the object containing the keyframes you want to modify is selected in the 3D Viewport.

2. Open the Graph Editor or Dope Sheet:

• Graph Editor: Offers precise control over the interpolation and values of keyframes.
• Dope Sheet: Provides a simplified overview and allows for basic adjustments to keyframe timing.

You can find these editors by splitting your existing window or adding a new editor from the editor type menu at the top-left corner of any Blender window.

3. Select Keyframes:

• Graph Editor:
  • Select All: Press A to select all keyframes for all animated properties of the selected object.
  • Box Select: Press B and drag a box around the keyframes you want to select.
  • Individual Curves/Channels: Click on the curve name (e.g., "Location X", "Rotation Z") in the sidebar to select all keyframes for that specific property.
• Dope Sheet:
  • Select All: Press A to select all keyframes.
  • Box Select: Press B and drag a box around the keyframes.
  • Select a Row: Click on the name of the animated property on the left to select all keyframes in that row.

4. Transform Keyframes:

Once the keyframes are selected, you can perform various transformations:

• Move: Press G to grab and move the keyframes along the timeline. This shifts their timing.
• Scale: Press S to scale the keyframes around the current frame. This alters the timing proportionally. You might need to set the 2D cursor to a fixed position (like the current frame) to achieve the proper scaling.
• Rotate: Press R to rotate the keyframes (primarily useful in the Graph Editor for manipulating curve shapes). Note that Rotation is less frequently used in this context.
• Scale Values (Graph Editor): In the Graph Editor, you can scale the values of the keyframes (e.g., increase the amplitude of a wiggle). Press S then Y to scale the values. You can restrict the scaling to only the Y axis to change the keyframe values.

5. Considerations:

• Linked Keyframes: Be aware that keyframes can sometimes be linked. Modifying one linked keyframe will affect all others that share the same data.
• F-Curves (Graph Editor): The Graph Editor shows F-Curves, which represent the interpolation between keyframes. You can directly manipulate these curves for fine-grained control.
• Multiple Objects: To change keyframes for multiple objects simultaneously, select all the objects before opening the Graph Editor/Dope Sheet. All animated properties from all selected objects will be visible, making adjustments possible for all of them at once.

Example: Shifting All Keyframes to Start Later

1. Select the object.
2. Open the Dope Sheet.
3. Press A to select all keyframes.
4. Press G to grab.
5. Move your mouse to the right (or enter a positive number) to shift all keyframes later in the timeline.
6. Click the left mouse button or press Enter to confirm the new position.

By understanding these techniques, you can efficiently modify all keyframes within your Blender animation projects.