Translations:Archive:Kdenlive/Manual/Effects/Alpha manipulation/Rotoscoping/24/en

To make the drawn mask follow the action in a clip...
Move the position in the clip by dragging the carat on the time line (1 or 3 in screenshot below) or by using the time code control in the rotoscope effect (2 in the screenshot)
Click add key frame (5 in the screen shot).
Now adjust the position of the nodes in the curve to match the action.
Kdenlive will calculate a path to move the nodes from the position they were in the previous key frame to the position you put them in at this keyframe. So you do not have to draw a curve for every frame in the clip.
To remove a key frame move to the frame with the key frame using the Go to previous keyframe (4) or Go to next keyframe (6) and then click the red X that the add key frame (5) becomes when you are on an existing keyframe.