Shape and Mask Drawing Tools

Shapes and masks (and paint strokes) are made with splines, and they’re created and edited using similar tools. This section covers the two spline-drawing methods that are available in Motion: Bezier splines and B-Splines. You can use Bezier shapes and B-Spline shapes interchangeably for any task. The default shape type is Bezier.

Bezier splines are good for drawing shapes for illustration. The controls used to manipulate Bezier splines are similar to those found in many other drawing and compositing applications, so they may already be familiar to you. Bezier controls lend themselves to the creation of precise, detailed shapes. Tangent handles adjust the curvature of the shape on either side of the control point, and this defines the surface of the shape.

Figure. Canvas showing a Bezier control point and its tangent handles.

B-Splines can also be used to draw shapes, but unlike Bezier controls, B-Splines are manipulated using only points—there are no tangent handles. Furthermore, the points themselves do not lie on the surface of the shape. Instead, each B-Spline control point is offset from the shape’s surface, pulling that section of the shape toward itself as if it was a magnet, in order to create a curve. By combining the influence of multiple B-Spline points, you can create different curves. B-Splines are extremely smooth—by default, there are no sharp angles in B-Spline shapes, although you can create sharper curves, if necessary.

Figure. Canvas window showing a B-Spline control point.

Because B-Spline controls are so simple, they’re easy to animate and manipulate. The tools you use for a particular task are largely a matter of personal preference.

Note: Shapes drawn with Bezier and B-Spline tools can be converted into paint strokes by selecting the shape’s Outline checkbox and choosing a different brush type in the Inspector. For more information, see Creating Paint Strokes.

Drawing Masks and Shapes Using Bezier Splines

This section describes how to draw a Bezier shape from scratch. These methods are identical whether you use the shape or masking tools. This section focuses on drawing shapes. For more information on drawing masks, see Using Masks to Create Transparency.

To draw a Bezier shape
  1. Click the Bezier tool in the Toolbar (or press B).

    Figure. Bezier tool in the Toolbar.

    Note: The Bezier Mask tool is located in the Mask tools section of the Toolbar.

    Figure. Bezier Mask tool in the Toolbar.

    The Bezier Tool HUD appears. (If it does not appear, press F7.) To change the color of the shape before it is drawn, use the color controls in this HUD. Select the Outline checkbox to create an outline with the shape. The Width slider adjusts the width of the outline. Once the shape is created, the Shape HUD appears.

    Note: Outlines can be added and edited after a shape is drawn.

  2. Click in the Canvas to draw the first point.

  3. To add additional points to further define the shape, do one of the following:

    • Click to make a linear corner point.

      Figure. Canvas window showing a linear corner point.
    • Click, then drag to make a curved Bezier point, adjusting it to the shape you want.

      Figure. Canvas window showing curved Bezier point.

    Note: Press Shift while making a curved point to constrain its tangents to 45-degree angles.

    While you’re drawing a shape, you can also use any of the point-editing procedures described below to move and adjust existing control points prior to finishing the shape. You can adjust any control point except the first one you created, because clicking the first point closes the shape.

    Tip: If you need a closer look at what you’re doing, magnify the Canvas while drawing a shape. Use Command-Equal Sign (=) to zoom in and Command-Hyphen (-) to zoom out. You can scroll around by pressing the Space bar as you drag in the Canvas. If you have a Multi-Touch trackpad, it’s even easier: pinch open or closed to zoom in or out, and use a two-finger swipe to scroll around.

  4. To finish the shape, do one of the following:

    • Click the first point you drew to create a closed shape.

      Figure. Canvas window showing a closed shape.
    • Press C to close the shape, joining the first point you created to the last.

    • Double-click anywhere in the Canvas to create the last point of an open shape.

    • Press Return to create the last point of an open shape.

      Figure. Canvas window showing an open shape.

    Note: Before a shape is closed, you can press Esc at any time to cancel the entire operation, deleting the shape.

    Immediately after finishing a shape, the Shape HUD appears and the Adjust Control Points tool is selected, which allows you to edit the shape you’ve just created.

    Note: Once you have finished drawing a shape, press Esc to change to Select/Transform mode.

Drawing Masks and Shapes Using B-Splines

This section describes how to draw a B-Spline shape. These methods are identical whether you’re using the shape or masking tools, but this section focuses on drawing shapes. For more information on drawing masks, see Using Masks to Create Transparency.

To draw a B-Spline shape
  1. Click the B-Spline tool in the Toolbar (or press B).

    Figure. B-Spline tool in the Toolbar.

    Note: If the Bezier tool is selected, pressing B once selects the B-Spline tool. If another tool is selected, such as the Text tool, press B twice to select the B-Spline tool. The B-Spline Mask tool is located in the Mask tools section of the Toolbar.

    Figure. B-Spline Mask tool in the Toolbar.

    The B-Spline Tool HUD appears. (If it does not appear, press F7.) To change the color of the shape before it is drawn, use the color controls in this HUD. Select the Outline checkbox to create an outline with the shape. The Width slider adjusts the width of the outline. Once the shape is created, the Shape HUD appears.

  2. Click in the Canvas to draw the first point.

  3. Continue clicking to draw additional points to define the shape you need.

    Note: Press Shift while making a curved point to constrain its tangents to 45-degree angles.

    As you create new B-Spline control points, keep the following rules in mind:

    • The control points you draw influence the shape of the curve from a distance. They do not lie directly on the surface of the curve.

      Figure. Canvas window showing curved line with B-Spline control points.
    • To create more detailed curves, create more points. However, it’s a good habit to use the fewest number of points necessary to create the amount of detail you need. Shapes with an excessive number of points can be difficult to edit later on.

      Figure. Canvas window showing simple and multi-point B-Spline curves.
    • In many instances, it is easier to create a loose group of control points first and then adjust them afterwards to create the precise curve you need in a later step.

      Figure. Canvas window showing an abstract shape being fine-tuned and made symmetrical.
  4. While drawing a shape, you can move and adjust the control points you’ve already created prior to finishing the shape. You can adjust any control point except the first one you created, because clicking the first point closes the shape.

    Tip: If you need a closer look at what you’re doing, you can magnify the Canvas while in the middle of drawing a shape. You can also scroll around by pressing the Space bar while you drag in the Canvas.

  5. When you’re ready to finish your shape, do one of the following:

    • Click the first point you drew to create a closed shape.

    • Press C to close the shape, joining the first point you created to the last.

      Figure. Canvas window showing a closed shape.
    • Press Return to finish an open shape at the last point you made.

      Figure. Canvas window showing an open shape.
    • Double-click anywhere in the Canvas to define the last point of an open shape.

      Figure. Canvas window showing an open shape.

    Note: You can press Esc at any time while drawing a shape to cancel the entire operation and delete the shape.

    Immediately after finishing a shape, the Shape HUD appears and the Adjust Control Points tool is selected, which allows you to edit the shape you’ve just created. Press Shift-S to change to the Select/Transform tool.

Controlling B-Spline Curvature

Each control point on a B-Spline path affects the curvature of the shape nearby. By default, these curves are very rounded, but you can adjust the degree of roundness, even creating corner points by adjusting the control point weight handle.

To modify the smoothness of B-Spline control points
  1. Create a shape using B-Splines.

  2. Command-drag one of the control points.

    A weight handle appears.

    Figure. Canvas showing B-Spline weight handle being adjusted.
  3. Drag the weight handle away from the control point to sharpen the path. Drag it towards the control point to smooth the path.

Drawing Masks Using the Freehand Mask Tool

This section describes how draw a freehand mask. Like the Paint Stroke tool, the Freehand Mask tool allows you to create a shape in one movement, rather than drawing the shape in a point-by-point fashion (like a Bezier or B-Spline shape). It is recommended to use a stylus and tablet when using the Mask Freehand tool. For more information on drawing masks, see Using Masks to Create Transparency.

To draw a freehand mask
  1. Select the layer you want to mask, click the Mask tool in the Toolbar, then choose the Freehand Mask tool.

    Figure. Freehand Mask tool in the Toolbar.

    The Freehand Mask Tool HUD appears.

  2. Adjust the controls in the Freehand Mask Tool HUD.

    • To change the blend mode of the mask before it is drawn, use the Mask Blend Mode pop-up menu in this HUD.

    • Adjust the Feather slider to soften the mask. Positive values spread the feathering outward, while negative values feather the shape inward.

      Figure. Canvas window showing an image of a leopard prior to being masked.
  3. Touch the stylus on the tablet to begin drawing the mask in the Canvas (if using a mouse, click in the Canvas, but don’t release the mouse button).

    Continue drawing around the object you are masking. To close the mask, finish the line at the mask’s starting point. A small circle will appear when the pointer is over the starting point.

    Note: If you don’t close the mask at its starting point, the mask is automatically closed when you release the mouse button.

    Figure. Canvas window showing mask close target.

    The mask is completed.

  4. Edit your control points to fine-tune the mask.

    For more information on editing control points, see How to Edit Shapes.

Figure. Canvas window showing leopard outlined by a mask.