5.5

861Motion User Guide
• Stencil: A checkbox that preserves the layer’s geometric transforms. If you’re creating
a mask with transformed Scale, Position, Rotation, or other parameters, select this
checkbox to use the modified layer.
• Stretch: A checkbox (available when Stencil is deselected) that stretches the mask to fit
the boundaries of the image and centers the mask on the layer’s center point.
Convert between shapes and masks in Motion
Because masks and shapes are created in similar ways but perform different tasks, there
are occasions where you may create a shape and later want to convert it into a mask, or
vice versa. Different options are available when converting shapes to masks, depending on
the type of object being masked. When you need to convert a shape to a mask, consider
the following:
• When a shape is converted to a mask and applied to a scaled object, the resulting
mask is scaled as well. This may lead to unexpected results. To prevent surprises, set
the object to 100% scale or place the object in a new group and apply the mask to the
group.
• Converting a shape that has been manipulated in 3D space into a mask may produce
unexpected results. For more information on working with masks in 3D projects, see
Mask a layer in Motion.
• When a transformed (scaled, rotated, or anchor point-adjusted) shape is converted to a
mask, the transforms are not maintained.
Note: Masks are cannot be applied to 3D paint strokes, 3D particle systems or replicators,
3D text, or unflattened 3D groups. To convert a shape to a mask on such an object, the
item must be flattened.
Convert a shape to a mask an image
1. In Motion, use any of the shape tools to create a shape.
Note: You can also add a preset shape from Shapes category in the Library.
2. In the Layers list, drag the shape object onto the layer to be masked.
The shape is converted into a mask. If the layer to which the mask is applied is not
centered in the canvas, the position of the mask is slightly offset. This is because the
position of the converted mask is dependent upon the original position of the shape
relative to the center of its parent group.
Convert a shape to a mask a group
You can convert a shape into a mask and apply that mask to any group in a project.
1. In Motion, use any of the shape tools to create a shape.
2. In the Layers list, drag the shape onto the group layer and pause, holding down the
mouse button, then when the drop menu appears, choose Move Mask To Group.