Movie mask clips unexpectedly #77445

New Issue

Deane Saunders-Stowe · 2020-06-05T15:53:54+02:00

2020-06-05 15:53:54 +02:00

System Information
Operating system: Linux-4.19.0-9-amd64-x86_64-with-debian-10.4 64 Bits
Graphics card: AMD PITCAIRN (DRM 2.50.0, 4.19.0-9-amd64, LLVM 7.0.1) X.Org 4.5 (Core Profile) Mesa 18.3.6

Blender Version
Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: 211b6c29f7
Worked: (newest version of Blender that worked as expected)

Short description of error
A vertex causes unexpected behaviour of a movie mask. The bottom half of the mask is clipped for several frames. If the offending vertex is moved, the clipping goes away and the mask appears as the correct shape.

Exact steps for others to reproduce the error
In the attached blend file, there is a highlighted vertex in the movie editor. Step through the sequence (bug occurs between 359-411) and watch the compositor for several frames. In the frames where the highlighted vertex does not move, clipping occurs and the masked area is smaller than the area in the mask editor. If the vertex is moved, the clipping goes away.

At some point during masking, I had dragged out control handles on two vertices and converted them back to vector type (whether it was this vertex or not, I can't recall). I had also at one point added a new vertex into the shape after having already keyframed several frames.
maskbug.blend

I have included a screenshot of the behaviour.

**System Information** Operating system: Linux-4.19.0-9-amd64-x86_64-with-debian-10.4 64 Bits Graphics card: AMD PITCAIRN (DRM 2.50.0, 4.19.0-9-amd64, LLVM 7.0.1) X.Org 4.5 (Core Profile) Mesa 18.3.6 **Blender Version** Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: `211b6c29f7` Worked: (newest version of Blender that worked as expected) **Short description of error** A vertex causes unexpected behaviour of a movie mask. The bottom half of the mask is clipped for several frames. If the offending vertex is moved, the clipping goes away and the mask appears as the correct shape. **Exact steps for others to reproduce the error** In the attached blend file, there is a highlighted vertex in the movie editor. Step through the sequence (bug occurs between 359-411) and watch the compositor for several frames. In the frames where the highlighted vertex does not move, clipping occurs and the masked area is smaller than the area in the mask editor. If the vertex is moved, the clipping goes away. At some point during masking, I had dragged out control handles on two vertices and converted them back to vector type (whether it was this vertex or not, I can't recall). I had also at one point added a new vertex into the shape after having already keyframed several frames. [maskbug.blend](https://archive.blender.org/developer/F8579387/maskbug.blend) I have included a screenshot of the behaviour. ![Screenshot_2020-06-04_18-54-05.png](https://archive.blender.org/developer/F8579388/Screenshot_2020-06-04_18-54-05.png)

Deane Saunders-Stowe commented

2020-06-05 15:53:54 +02:00

Added subscriber: @RexxDeane

Philipp Oeser commented

2020-06-05 16:21:05 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-06-05 16:21:05 +02:00

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

Philipp Oeser commented

2020-06-05 16:21:05 +02:00

I can confirm.
I recall there was a related report, let me dig that up.

I can confirm. I recall there was a related report, let me dig that up.

Philipp Oeser commented

2020-06-05 16:41:51 +02:00

I thought #69079 (KeyingScreen Compositor node emits "black holes" ) was related (but seems like this is a different way rasterizing/filling/).

Anyways, assume we can classify this as a bug.

I thought #69079 (KeyingScreen Compositor node emits "black holes" ) was related (but seems like this is a different way rasterizing/filling/). Anyways, assume we can classify this as a bug.

Campbell Barton commented

2020-06-12 13:11:07 +02:00

Added subscriber: @ideasman42

Campbell Barton commented

2020-06-12 13:11:07 +02:00

From a quick look, the curve is flipped, switching direction makes it work. Even so, this should still be supported.

Sergey Sharybin commented

2020-06-12 13:14:18 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2020-06-12 13:14:18 +02:00

Here is a file with mask consisting only of 4 point.

@ideasman42 , seems to be something in mask_rasterize.c which is hard to me to follow. Maybe some watertight issues. One of the possible solution in this specific case is to somehow rasterize with resolution of 1. However, it wouldn't work in the case if there is curved segment added to the mask, and will only masquerade the actual problem. Would you have time to look into this bug?

maskbug_4_points.blend

Here is a file with mask consisting only of 4 point. @ideasman42 , seems to be something in `mask_rasterize.c` which is hard to me to follow. Maybe some watertight issues. One of the possible solution in this specific case is to somehow rasterize with resolution of 1. However, it wouldn't work in the case if there is curved segment added to the mask, and will only masquerade the actual problem. Would you have time to look into this bug? [maskbug_4_points.blend](https://archive.blender.org/developer/F8611075/maskbug_4_points.blend)

Georg K commented

2022-06-21 16:39:37 +02:00

Added subscriber: @georgK

Georg K commented

2022-06-21 16:39:37 +02:00

Can confirm this bug still exists in 3.3.0
version: 3.3.0 Alpha, branch: master, commit date: 2022-06-21 08:10, hash: ee78c860b8, type: Release
build date: 2022-06-21, 12:12:39
platform: 'Linux-5.17.15-1-MANJARO-x86_64-with-glibc2.35'

Can confirm this bug still exists in 3.3.0 version: 3.3.0 Alpha, branch: master, commit date: 2022-06-21 08:10, hash: ee78c860b8aa, type: Release build date: 2022-06-21, 12:12:39 platform: 'Linux-5.17.15-1-MANJARO-x86_64-with-glibc2.35'

Philipp Oeser removed the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Movie mask clips unexpectedly #77445