User Guide

Chapter 7: Sprite Technology
Transparency effect
Like an alpha channel in a paint object, a channel mask is basically a grayscale image. Channel masks
can be edited using image-editing tools and techniques, similar to alpha channels.
You can think of a channel mask as a template for transparency. The channel mask is the same size
as the masked object and is aligned with it. In the case of a paint object, the channel mask has the
same resolution and number of pixels as the paint object.
Channel masks, like grayscale images, contain pixels that are assigned 256 possible lightness levels,
or luminance values. Luminance values in a channel can range from 0 (black) to 255 (white).
In an alpha channel, luminance corresponds to selection intensity. In a channel mask, luminance
values correspond to 256 levels of transparency, from 100% to 0% transparency, in the masked
object. Black pixels (0 luminance) produce 100% transparency, while white pixels (255 luminance)
produce 0% transparency.
Therefore, when you paint in a channel mask, painting with black produces clear areas and painting
with white produces opaque areas in the masked object. Painting with gray produces partial
transparency relative to the gray value, with darker grays producing greater transparency than
lighter grays.
Black in a channel mask produces 100% transparency. A feathered edge produces partial
transparency.
Channel mask and paint
object
673