Weight Painting with Mirror above Armature Paints weird #71804

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LeRoy · 2019-11-23T05:07:37+01:00

LeRoy commented

2019-11-23 05:07:37 +01:00

System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.48

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: 26bd5ebd42
Worked: 2.80

Short description of error
When doing weight painting, if the Mirror Modifier is above an Armature modifier, you will be unable to paint directly on the model

Exact steps for others to reproduce the error

Create a Cylinder
Split the cylinder so that it is cut in half, if viewed from above it should look like a C
Add a Mirror modifier and Mirror across Y axis (or X, whichever makes it a cylinder again)
Add an armature, extend it along Z 3 times.
Parent the armature to the object using Automatic Weights.
Ensure that the object has the Mirror Modifier above the Armature Modifier.
Post the armature at some angle away from the object (the object should follow as expected)
Go to weight painting. Try to paint anywhere where the object moved to. Nothing happens
Try to paint where the object Was if it was not posed. It will paint the object as if it were not posed.

See attached file for example. I attached 2 files because I wasnt sure which one had it in the right state.

I found this while working on a character model that I had started in 2.80. This was working fine in 2.80. test.blend test.blend

**System Information** Operating system: Windows-10-10.0.18362 64 Bits Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.48 **Blender Version** Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: `26bd5ebd42` Worked: 2.80 **Short description of error** When doing weight painting, if the Mirror Modifier is above an Armature modifier, you will be unable to paint directly on the model **Exact steps for others to reproduce the error** 1. Create a Cylinder 2. Split the cylinder so that it is cut in half, if viewed from above it should look like a C 3. Add a Mirror modifier and Mirror across Y axis (or X, whichever makes it a cylinder again) 4. Add an armature, extend it along Z 3 times. 5. Parent the armature to the object using Automatic Weights. 6. Ensure that the object has the Mirror Modifier above the Armature Modifier. 7. Post the armature at some angle away from the object (the object should follow as expected) 8. Go to weight painting. Try to paint anywhere where the object moved to. Nothing happens 9. Try to paint where the object Was if it was not posed. It will paint the object as if it were not posed. See attached file for example. I attached 2 files because I wasnt sure which one had it in the right state. I found this while working on a character model that I had started in 2.80. This was working fine in 2.80. [test.blend](https://archive.blender.org/developer/F8157552/test.blend) [test.blend](https://archive.blender.org/developer/F8157556/test.blend)

LeRoy commented

2019-11-23 05:07:37 +01:00

Added subscriber: @Semple