Enabling Keyframing

Before you can set keyframes to create any animation you have to enable the Animate button. When enabled, the Animate button is red.

Note: You can also press A to toggle the Animate button.

When this button is turned off, you can adjust any category at any frame, but the value does not change over time. The value of the category is set to the last specified value for the entire clip; when keyframes already exist, the value of the category is offset over the entire clip.