GPencil Time Offset Modifier together with Armature Modifier or/and Lattice Modifier broken in 2.93.3 #91060

New Issue

Dmitry · 2021-08-30T23:25:49+02:00

Dmitry commented

2021-08-30 23:25:49 +02:00

System Information
Operating system: Win10

Blender Version
Broken: 2.93.3
Worked: 2.92
Caused by f3bf87e588

Short description of error
GPencil Time Offset Modifier buggs Armature or/and Lattice modifier if applied together to the GPencil Object.

Exact steps for others to reproduce the error

Open fresh 2D Animation Template (File -> New -> 2D Animation).
Go to Frame number 5.
Write big number "5" in the middle of screen.
Delete empty GPencil Frames at Frame number 1.
Switch to Object Mode.
Add Armature.
Select GPencil Object.
Add Time Offset Modifier to GP Object (set Mode = Fixed Frame; set Frame = 5).
Add Armature Modifier to GP Object (set Object = Armature, set Bind To = Bone Envelopes).
Select any Frame before number 5 (for example Frame 2)
Select Armature.
Switch to Pose Mode.
Rotate Bone and notice how weird GPencil drawing reacts.

Fixes if you use Show Overlays on/off command.
Works as expected if Frame >= 5.

or to reproduce from file

Open .blend file
Use {key R} to rotate bone

GP_TimeOffset_Armature.blend

**System Information** Operating system: Win10 **Blender Version** Broken: 2.93.3 Worked: 2.92 Caused by f3bf87e588 **Short description of error** GPencil Time Offset Modifier buggs Armature or/and Lattice modifier if applied together to the GPencil Object. **Exact steps for others to reproduce the error** - Open fresh 2D Animation Template (File -> New -> 2D Animation). - Go to Frame number 5. - Write big number "5" in the middle of screen. - Delete empty GPencil Frames at Frame number 1. - Switch to Object Mode. - Add Armature. - Select GPencil Object. - Add Time Offset Modifier to GP Object (set Mode = Fixed Frame; set Frame = 5). - Add Armature Modifier to GP Object (set Object = Armature, set Bind To = Bone Envelopes). - Select any Frame before number 5 (for example Frame 2) - Select Armature. - Switch to Pose Mode. - Rotate Bone and notice how weird GPencil drawing reacts. Fixes if you use Show Overlays on/off command. Works as expected if Frame >= 5. --- or to reproduce from file - Open .blend file - Use {key R} to rotate bone [GP_TimeOffset_Armature.blend](https://archive.blender.org/developer/F10353721/GP_TimeOffset_Armature.blend)

Dmitry commented

2021-08-30 23:25:49 +02:00

Added subscriber: @ostrijper4ik

Pratik Borhade commented

2021-08-31 08:46:28 +02:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2021-08-31 08:52:48 +02:00

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

Pratik Borhade commented

2021-08-31 08:55:36 +02:00

May similar to #89433 (GP: Time offset and Armature modifier causes glitches) ?

Antonio Vazquez commented

2021-08-31 10:41:33 +02:00

Added subscribers: @lichtwerk, @antoniov

Antonio Vazquez commented

2021-08-31 10:41:33 +02:00

I have been looking at the modifier code and the Frame (gpf) variable is correct in both cases. It looks in some place the calculation of the deformation is using the current frame number. The defomration is done reusing the mesh deform functions (armature_vert_task_with_dvert).

@lichtwerk do you know this deformation code?

I have been looking at the modifier code and the Frame (`gpf`) variable is correct in both cases. It looks in some place the calculation of the deformation is using the current frame number. The defomration is done reusing the mesh deform functions (`armature_vert_task_with_dvert`). @lichtwerk do you know this deformation code?

Antonio Vazquez commented

2021-08-31 10:54:50 +02:00

I think I have seen something...checking.

Philipp Oeser self-assigned this 2021-08-31 10:59:08 +02:00

Philipp Oeser commented

2021-08-31 10:59:08 +02:00

Will check.