In this quick sample, I started with a Clear patch set to clear the
patch to
a light gray with an alpha of 1.0. Then I added a Sprite. To the
sprite, I
connected a Color Transformation. I set the initial color of the Color
Transformation to a light blue with an alpha of 1.0. Then I
connected two
Interpolation patches to the Color Transformation; the first
Interpolation
ranges from 0.0 to 360.0 and drives the Hue Rotation. The second
Interpolation ranges from 0.0 to 1.0 and drives the Alpha Factor. I
was
expecting the Sprite to gradually fade in from totally invisible to
the
color of the moment. Instead, the Sprite goes from black to the
color of the
moment.
That's because blending is disabled: set blending mode to "Over" on
the Sprite (in OpenGL ,blending operations are separated from alpha
values)
