Gradient Image with Blend Alpha

Steps causing the bug to occur

This appears to be an issue with Blend Images or possibly Make Linear Gradient Image. When using Blend Images set to normal-alpha to composite Make Linear Gradient Image fading from green to transparent over a solid color using Make Color Image, when the second gradient color is set to 0 opacity, the image alpha channel becomes solid with a hard edge. Bumping up the opacity can make it blend smoothly, but then the Make Color Image solid color shifts as the second gradient color becomes less opaque. Hope this makes sense.

(Almost added this to @alexmitchellmus thread on premultiplying alpha, wasn’t sure if it’s an isolated issue or related to Vuo color/alpha in general: )

Yellow hues should be transparent:

Screen Shot 2016-05-01 at 10.20.48 AM copy.png

In case one wonders why I’m not simply using one Make Gradient Image with two colors, the attached comp is a simplified test to demonstrate the issue.

Screen Shot 2016-05-01 at 9.52.46 AM.png

Gradient-BlendNormalAlpha.vuo (2.63 KB)

Gradient-BlendNormalAlpha.vuo (2.63 KB)

Using layers instead of images appears to work better with this issue.

Confirmed. This is a bug in Vuo’s handling of the alpha channel.

Fixed in Vuo 1.2.2.