Adobe After Effects - Manual (Page 320)

Invert
Blur
Tolerance
Threshold
Minimum Area
Corner Roundness
Apply To New Layer
Preview
To the top
Note:
5. Set any of the following options:
Inverts the input layer before searching for edges.
Blurs the original image before generating the tracing result. Select this option to reduce small artifacts and to smooth jagged edges in
the tracing result. Deselect this option to closely trace details in a high-contrast image. Specify the radius, in pixels, of the area used for the
blurring operation. Larger values result in more blur.
How far, in pixels, the traced path is allowed to deviate from the contours of the channel.
Specifies, as a percentage, the value that a pixel’s channel must have for that pixel to be considered part of an edge. Pixels with
channel values over the threshold are mapped to white and are opaque; pixels with values under the threshold are mapped to black and are
transparent.
Specifies the smallest feature in the original image that will be traced. For example, a value of 4 removes features smaller
than 2 pixels wide by 2 pixels high from the tracing result.
Specifies the roundness of the mask curve at vertices. Enter a higher value for smoother curves.
Applies the mask to a new solid the same size as the selected layer. This control is automatically selected for layers
that have Collapse Transformations enabled—it creates a new layer the same size as the composition that contains the layer.
Select to preview the mask results and the results of the various options of the Auto-trace command.
Creating shapes and shape layers
You create a shape layer by drawing in the Composition panel with a shape tool or the Pen tool. You can then add shape attributes to existing
shapes or create new shapes within that shape layer. By default, if you draw in the Composition panel when a shape layer is selected, you create
a new shape within that shape layer, above the selected shapes or group of shapes. If you draw in the Composition panel using a shape tool or
Pen tool when an image layer other than a shape layer is selected, you create a mask.
Press F2 to deselect all layers before drawing in the Composition panel to create a new shape layer.
You can create shapes and shape layers using any of the following methods:
Draw a path using the shape tools or Pen tool. Drawing a mask path is similar to drawing a shape path. (See Create a shape or mask by
dragging with shape tools and Create a Bezier shape or mask using the Pen tool .)
Convert a text layer to shapes on a shape layer by using the Create Shapes From Text command. (See Create shapes or masks from text
characters .)
Convert a mask path to a shape path.
Convert a motion path to a shape path. (See Create a mask or shape from a motion path .)
Paste a path copied from another layer or from Adobe Illustrator, Photoshop, or Fireworks. (See Copy a path from Illustrator, Photoshop, or
Fireworks .)
Create a new, empty shape layer by choosing Layer > New > Shape Layer.
In most cases, a new shape has a fill and a stroke that correspond to the Fill and Stroke settings in the Tools panel at the time that the shape is
drawn. You can use the same controls in the Tools panel to change these attributes for a selected shape after it has been drawn. Shapes created
from text are created with fills and strokes that match the fills and strokes of the original text.
To draw a mask on a shape layer, click the Tool Creates Mask button in the Tools panel with a shape tool or Pen tool active. For more
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