Blackmagic Forum

The Fusion tab's paint node, Stroke mode, "write on then off" option under stroke controls does not appear to consistently work correctly. Is there a setting I'm missing, or is this a known bug?

Fresh project, fresh timeline. In this example I created a fusion clip on the timeline. In the clip I created a default background node, connected to a paint node, connected to mediaOut. Selecting the paint node, I clicked "Stroke" in the viewer, then in the stroke controls area I changed the stroke animation to "Write On then Off".

I drew a curving stroke on the viewer. Moved the timeline ahead a few seconds and drew a second curving stroke (different location). Moved the timeline ahead again and drew a third.

When played, the first and second strokes flash "completely on" for one frame, then there is a pause, then they draw on (the "write on" part of "write on write off"). They do not write off later. The third stroke appears as a "dot" for one frame, then after a pause it writes on and then writes off (much closer to what I expect based on reading the manual - if the dot and pause were not there, it would be the expected behavior).

When I view the spline, it appears that there is a "write off" on the first two strokes but at a ridiculous time (like 45 minutes later). I'm unable to even get the spline editor to zoom effectively to see the slope of the strokes.

My puzzlements are around (1) the flash (or dot) and pauses; (2) the lack of reasonably displaced "write off" part when write-on-write-off is selected.

Is one of the parameter settings supposed to control the amount of displacement? I did not see such in the manual when I searched "write on write off" (p2194).

I have attached the example .drt timeline export (zipped).

To get rid of the dot at the beginning, go to the 2nd keyframe and set the Write On>End value to 0. Then the animation should start and go smoothly from start to end.

For the second issue, it seems to happen if you hit the "Zoom To Fit" button. If you zoom with the mouse, it seems to keep the keyframes where they should be, but if you hit "Zoom To Fit", the range for the keyframes goes huge.

@xunile, thank you both for the workaround for the first issue, and for investigating. I feel more confident that this is indeed a bug(s).

On 1) Interestingly, that keyframe seems to be at the spot where the timeline was positioned when I started drawing (and hence where I expected the "write on" to start - the actual result is starting later, although I'm capable of dragging a block of keyframes to shift it back to where it belongs).

I can use the manual adjustment workaround of the Write on/end parameter to clean up the "write on" part of my project.

On 2) I agree that manual zooming lets me see the "write on" behavior, but the "write off" part that is supposed to be there is not for the first two example draws. I don't know why DR is acting inconsistently here.

Obviously frustrating to not have the feature work as documented.