I would like to fill a rectangular marquee area with a gradient that stretches from the left to the right of the rectangular marquee area, starting at one color and ending at a second color. This is easy to do in Photoshop and I know how to do this.
However, I would like the entire gradient to fade to transparent at the TOP and BOTTOM (i.e., in the perpendicular direction). If I desired this effect in the horizontal direction, it would be easy to do in Photoshop because I would just set the "smoothness" parameters of the gradient as desired, along with the color parameters.
However, because I want the fade to transparency to occur in the VERTICAL direction, while the color gradient occurs in the HORIZONTAL direction, I do not know how to do this.
How can a create a color gradient in one direction, while setting a fade to transparency in the perpendicular direction, in Photoshop CS5?