Microsoft KB Archive/167445

= Microsoft Knowledge Base =

HOWTO: Applying Effects to a Region Defined by the Alpha Channel
Last reviewed: April 28, 1997

Article ID: Q167445

The information in this article applies to:


 * Softimage Eddie for IRIX, versions 3.2a, 3.2b

SUMMARY
This procedure shows you how to apply an arbitrary effect, such as Color map or Mix, so that it only affects the region that is defined by the alpha channel.


 * 1) Attach the image (that has an alpha channel defining a specific region) to the source target.
 * 2) Attach the same image to the OptionalBackground target of that tool.
 * 3) In the Input Editor, select the A-atop-B blend (the fifth one from the left in the top row).

As you modify the parameters the changes only occur inside the region defined by the alpha channel.