VSE: Frame Overlay incorrectly applies Transform to reference frame, ignores keyframes #90829

New Issue

Lukas W · 2021-08-21T15:30:15+02:00

Lukas W commented

2021-08-21 15:30:15 +02:00

System Information
Operating system: Ubuntu 20.04.2
Graphics card: AMD® Verde

Blender Version
Broken: 2.93.3
Worked: don't know

While Frame Overlay is active and set to "Reference" or "Rectange", the video sequencer applies transformations to the reference frame even when that frame has a different transformation keyframed. The expected behaviour is that the reference frame looks exactly as it does when that particular frame is active.

Open attached file vseoverlaytransform.blend
Note that Frame Overlay is active and Overlay Type set to "Reference"
Alter the Rotation parametre of the text strip
Note that the displayed frame transforms as you change the value
Disable Frame Overlay and jump to the first frame
Note that the transformation parametre has a keyframe at 0 deg, but the displayed text is still rotated
Press Ctrl-R (Refresh All) and note that the text jumps back into its unrotated state

**System Information** Operating system: Ubuntu 20.04.2 Graphics card: AMD® Verde **Blender Version** Broken: 2.93.3 Worked: don't know While Frame Overlay is active and set to "Reference" or "Rectange", the video sequencer applies transformations to the reference frame even when that frame has a different transformation keyframed. The expected behaviour is that the reference frame looks exactly as it does when that particular frame is active. - Open attached file [vseoverlaytransform.blend](https://archive.blender.org/developer/F10300476/vseoverlaytransform.blend) - Note that Frame Overlay is active and Overlay Type set to "Reference" - Alter the Rotation parametre of the text strip - Note that the displayed frame transforms as you change the value - Disable Frame Overlay and jump to the first frame - Note that the transformation parametre has a keyframe at 0 deg, but the displayed text is still rotated - Press Ctrl-R (Refresh All) and note that the text jumps back into its unrotated state

Lukas W commented

2021-08-21 15:30:15 +02:00

Added subscriber: @geloescht

Philipp Oeser commented

2021-08-23 13:30:12 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-08-23 13:30:12 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Philipp Oeser commented

2021-08-23 13:30:12 +02:00

Can confirm the behavior.

tintwotin commented

2021-08-23 13:34:34 +02:00

Added subscriber: @tintwotin

tintwotin commented

2021-08-23 13:34:34 +02:00

Frame Overlay is generally a very poorly designed tool. An attempt to improve it: https://developer.blender.org/D10503

Lukas W commented

2021-08-23 15:15:08 +02:00

I've investigated the source a bit and think I have found the culprit. In this line of input_preprocess()
https://developer.blender.org/diffusion/B/browse/master/source/blender/sequencer/intern/render.c$615
the timeline_frame is lost since sequencer_preprocess_transform_crop() doesn't take a parametre for the frame to render. Then in sequencer_image_crop_transform_matrix() the transform is retrieved for the current frame. I guess we would need to pass timeline_frame through to those functions so the correct transform can be retrieved.

I've investigated the source a bit and think I have found the culprit. In this line of `input_preprocess()` https://developer.blender.org/diffusion/B/browse/master/source/blender/sequencer/intern/render.c$615 the `timeline_frame` is lost since `sequencer_preprocess_transform_crop()` doesn't take a parametre for the frame to render. Then in `sequencer_image_crop_transform_matrix()` the transform is retrieved for the current frame. I guess we would need to pass `timeline_frame` through to those functions so the correct transform can be retrieved.

Richard Antalik commented

2021-10-25 05:14:51 +02:00

Added subscriber: @iss

Richard Antalik commented

2021-10-25 05:14:51 +02:00

You can't really pass timeline_frame to transform function so they can lookup animation at that particular frame. It is possible technically, but it violates principles of how these values are evaluated. In past VSE did evaluate strip animation internally. Now this should be done by dependency graph only. But this would require either VSE to modify current frame and re-evaluate scene, which also violates these principles. Another option is for VSE to have own dependency graph, that it has full control of. This could resolve some other issues too, but I am not quite sure at what level(s) this should be implemented.

I will classify this as known issue, since this is not trivial to resolve and it does require design change and approval

You can't really pass `timeline_frame` to transform function so they can lookup animation at that particular frame. It is possible technically, but it violates principles of how these values are evaluated. In past VSE did evaluate strip animation internally. Now this should be done by dependency graph only. But this would require either VSE to modify current frame and re-evaluate scene, which also violates these principles. Another option is for VSE to have own dependency graph, that it has full control of. This could resolve some other issues too, but I am not quite sure at what level(s) this should be implemented. I will classify this as known issue, since this is not trivial to resolve and it does require design change and approval

Philipp Oeser removed the

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VSE: Frame Overlay incorrectly applies Transform to reference frame, ignores keyframes #90829