To edit shape, simply double click at the shape you want to edit or click vertex at toolbar to change to vertex mode.
In vertex mode, the shape control points will be shown. The line between points can be a straight line or a curve. Pink control point is first point of the path. This is useful if you use stroke start or stroke end animation to show which point will the animation begin.
Adding Control Points
To add control points, click at any points between the lines. A curve control point will then be added. You can also hold down the CMD key and click on a line between the two points, as a result, a point will be inserted exactly at middle of the line.
Selecting Control Points
To select a control point, just click at the desired control point. To select multiple control points, drag mouse to enclose desired control points.
Moving Control Points
You can click and drag control points around to change their position. To delete them, simply click Backspace or Delete button on your keyboard.
Modifying Control Points
When moving control point, you can hold modifier key for different control point behaviour.
No Modifier: Control points are opposite of each other and have same distance to main point.
CMD : Control points are disconnected from each other.
OPTION : Control points mirror each other, but the distance from control point to main point is different.
SHIFT : Control point is changed by 15 degree.