Manipulating Vertices and Tangents

You can manipulate vertices and tangents during and after mask creation. Edit vertices and tangents gesturally when the Tools drop-down mode is set to Select or Break Tangents. Alternatively, edit them using the parameters in the Vertices menu.

Vertices selected as a group can be transformed using the Edit Box. The angle and length of tangent handles can also be manipulated as a group.

Selecting Vertices and Tangents

You can select vertices and tangent handles using the Select option of the Tools drop-down:

• To select an individual vertex or tangent handle, click the vertex or tangent handle.
• To select multiple vertices, Ctrl-drag a selection box over a series of vertices.
• To select multiple vertices using the pen, press the pen button and drag a selection box over a series of vertices.
• To add more vertices to an existing selection, press Shift+Ctrl and drag a selection box over the additional vertices.
• To deselect all vertices, click anywhere outside the mask.

Moving Vertices and Tangents

You can move vertices and tangents using the Select option of the Tools drop-down:

• To move a vertex or tangent in any direction, click the vertex or tangent and drag.
• To move selected vertices in any direction, click one of the selected vertices and drag.
• To ensure better continuity on a garbage mask, automatically adjust tangents as you move vertices or scale the mask. Enable Auto Adjust and drag a vertex. To toggle temporarily enable or disable Auto Adjust, press and hold G and then drag a vertex. Auto Tangents must be enabled to use the Auto Adjust feature (you can toggle Auto Tangent on-the-fly using the GMask: Auto Tangent Toggle Mode keyboard shortcut).
• To keep tangent handles an equal length, Ctrl+Alt-drag one vertex handle to automatically change the length of the other tangent handle at the same time.

You can use the Vertices menu to move vertex and tangent positions.

The Selection fields display the current position of the vertex. If multiple vertices are selected, the position displayed is of the vertex that is closest to the initial vertex created in the mask.

Breaking, Removing, and Adding Tangents

You can separate two tangent handles (break the tangent) and move them separately option from the Tools drop-down:

• To break and move a tangent handle, select Break Tangent and click the tangent handle. The tangent is displayed as a dashed line, indicating it is "broken."
• To reconnect two broken tangent handles, click the vertex or select Auto Tangents and click either of the two tangent handles. The tangent is displayed as a solid line (you can toggle Auto Tangent on-the-fly using the GMask: Auto Tangent Toggle Mode keyboard shortcut).
• To change the position of an individual tangent handle after releasing the cursor, use the Select option in the Tools drop-down.

In the Vertices menu, use the fields in the Tangents section to change the length and angle for the incoming and outgoing tangent handles. If the tangents do not combine to form a straight line, the tangents will be broken and displayed as a broken line.

You can also use the Break option to remove tangents from vertices by clicking the vertex while in Break mode. When you remove a tangent, the interpolation of the spline between the two vertices is modified.

The shape of the border line differs depending on whether adjacent vertices are broken:

• If adjacent vertices are unbroken, the border line curves as it approaches the vertices.
• If adjacent vertices are broken, the border line is straight as it approaches the vertices.

You can create a garbage mask composed entirely of straight edges by removing the tangents from all the vertices:

• To remove the tangent of a vertex, select Break Tangent and click the vertex.
• To add a tangent back to a vertex, select Auto Tangent and click the vertex. Alternatively, using the Break Tangent option, click the vertex and drag the tangent out again.