Edge masking artefacts on higher subdiv levels when removing the mask from lower subdivs #76862

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.50

Blender Version
Broken: version: 2.90 (sub 2), branch: master, commit date: 2020-05-15 19:12, hash: eaf7d36d66

Short description of error
This is a follow-up report on this bug report I made: https://developer.blender.org/T76386

To quickly summarise, there are still masking artefacts that aren't removed when you delete a mask at a lower subdiv level. It only deletes the mask that all subdiv levels share, but in the process the edges of the mask remain at the higer levels because said geometry doesn't exist on the lower levels. This causes problems like these to occur:
Desktop 2020.05.17 - 00.35.46.01.mp4

Exact steps for others to reproduce the error

Take a cube and subdivide it.
Go down to level 0 and try to mask the mesh, which will be completely invisible. Then pick any subdiv level above it and mask.
Remove the mask at a lower subdiv above level 0 and then move up one level. The mask edges should still be there.
Repeat 3) until you reach the highest subdiv level.

Added subscriber: @Frozen_Death_Knight

Added subscriber: @TheRedWaxPolice

I can confirm that...

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

Added subscriber: @Edvard-Svensson

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Edge masking artefacts on higher subdiv levels when removing the mask from lower subdivs #76862