Apple Motion 4 - Manual (Page 1027)

Matte Filters
Matte filters are used to modify mattes.
Matte Choker
This filter increases or decreases the semi-transparent area of an object’s alpha channel
by performing a gamma correction (similar to the Gamma color correction filter) to all
regions of the alpha channel falling between solid black and solid white. This allows you
to widen or narrow the semi-transparent areas within an object, while leaving all
100-percent solid and transparent areas unaffected.
Parameters in the Inspector
Edge Thin: Higher positive edge thin values eat into the alpha channel, eliminating
fringing around the edges of translucent areas. Negative values fill in translucent areas,
filling in holes and widening the matte into regions of fringing.
Feather: Lower values reduce the amount of translucency in a matte, but this results in
harder edges around holes and edges in the alpha channel.
Mix: Sets what percentage of the original image is blended with the filtered image.
HUD Controls
The HUD contains the following controls: Edge Thin and Feather.
Matte Magic
This filter shrinks and softens the edges of a matte.
Original image with rectangular matte Matte Magic filter applied
Parameters in the Inspector
Shrink: Shrinks the edges of the matte with a soft edge to eat into the alpha channel, to
reduce fringing.
Feather: Feathers the edges of the matte.
Mix: Sets what percentage of the original image is blended with the filtered image.
Note: The Matte Magic filter has no effect on images with a solid alpha channel.
1027 Chapter 16 Using Filters