Autodesk 62205-051408-9001 User Guide - Page 264

10 Using Masks • CTRL-click a Bezier control point to make it a linear control point. Note: Press SHIFT while dragging a tangent handle to rotate the handle in multiples of 45 degrees. The tangent lines disappears, the shape of the curve is flat at that point. • ALT-drag a point to adjust the length of both sides of the unbroken tangent handle at the same time. When you ALT-drag an unbroken tangent handle, both tangent handles are automatically given the same length. Using Active Control Points Use the Active control point option to determine whether mask control points are active or inactive on a frame or range of frames. When a mask control point is active, the curve of the spline intersects the active control point. When the control point is inactive, the mask spline ignores the control point. Active Control Point Inactive Control Point • Press CTRL while dragging a tangent handle to break a tangent handle. CTRL-drag again to make the handle continuous. • Once a tangent handle is broken, you can continue working with the broken handle. When performing masking or rotoscoping, it is often necessary to add control points to a mask at various frames to accommodate changes in the shape of the subject being masked. Also, control points added to a mask at certain frames may no longer be necessary at other points in the clip. You can affect the shape of an animated mask at specific frames by using active and inactive control points. Note: If you are animating a mask, deleting control points during the animation causes interpolation problems. Use the Active button in the Toolbar to turn on or off your control points. 248