Operating system: Linux-5.4.0-47-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: Quadro GP100/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-09-17 05:34, hash: rBf085ebba58d7
Short description of error
When sculpting on a shapekey it works just fine but if a subdivision surface modifier is used (or Multires with the "Scultp Base Mesh" option used) it won't work.
Instead of targeting the vertex positions of the shapekey it will always go for the base shape.
Exact steps for others to reproduce the error
- Create an object and add a base and Key 1 shapekey
- Change the value for "key 1" to 1
- Add a subdiv modifier and subdivide
- Enter sculpt mode and disable the "Use Deform only" option in the header
- Try sculpting the shapekey
- Enable the Grab Active Vertex option in the Grab brush to see the targeted wires more clearly