Is it possible to animate the opacity of a grease pencil layer? I'm trying to have a grease pencil fade in and out over a number of frames. I'm able to get this behaviour in the blender viewport, but not when I render. I've created a minimal example which is available here:



The minimal example has a grey square, drawn in the default "Lines" layer of the default "Stroke" grease pencil. The opacity of this layer is set to transition from 1 at the start to around 0.1 at the end. When I play in the blender viewport, I see a smooth transition. When I hit "render animation", I see no change in opacity for different frames, and the rendered opacity matches whichever frame I have selected in the UI. "Render animation" will still correctly render motion, if I add location keyframes, but the opacity still behaves in the described manner.

Is there a way to make the render output respect the transition between opacity values?

Steps to create the minimal example:


Draw a square in a new 2D animation
Set end frame to 20 in the timeline
Create a keyframe for the opacity property of the "Lines" layer, at frame 0
Create another keyframe for the opacity property of the "Lines" layer, at frame 20
In the graph editor, drag the opacity at frame 20 down to around 0.1
This appears to have been a bug in blender 2.81. The example above behaves as expected in blender 2.82.