Add Butthead to Motion Dock

  1. Click Edit layout in Motion Dock’s top bar.
  2. Click an empty area of the layout and choose Butthead from the module picker.
  3. Click Exit layout mode to use the tool.

If Butthead is already in this layout, use its existing slot.

Round a line’s ends

  1. Open a composition in After Effects. Deselect all layers.
  2. Choose the Pen tool. Set a visible Stroke width and set Fill to None.
  3. Click two points in the Composition panel to draw an open line. Finish drawing, then select the new shape layer in the timeline.
  4. In Butthead, click the cap button Round, the second button below the sample.

The line now has rounded ends. The join button also named Round is farther right and changes corners instead.

If you see No active composition, open the composition in a viewer. For Select shape layers or strokes or No strokes in the selection, select the shape layer and check that it contains a Stroke. Unlock it if Butthead reports Selected layers are locked.

Add one arrowhead

Click the outlined tip at the lower-right end of Butthead’s sample. With default settings, the line gains a triangle arrowhead. It sits in a group named Butthead ▸ end inside the same shape layer.

Your line should now have a round start and a triangle at the end. Use After Effects’ Undo once to remove the arrowhead, or twice to undo the cap change too.