Pin Mapping for Volume Annotations

[fm3]

Detailed Description

When a mapping is available for a segmentation layer, the segment IDs change. This interacts with volume annotations that use fallback segmentations.

Currently, the mapping can freely be selected at any point in time. When the user brushes, the brushed buckets are copied into the volume annotation as they currently are shown. When the user disables the mapping later, the brushed buckets stay “mapped”. When another mapping is activated, bug #5427 even hides all brushed changes and shows the fallback layer only.

We should consider how we can ensure consistency between the fallback layer data and volume annotation data. A possibility could be to pin the selected mapping in a volume annotation once you start brushing. Separating the volume annotation from the selected mapping could remove all so-far brushed changes, just like unlinking the fallback layer does.

Context

Volume annotations do make sense in the context of mappings. It is currently far too easy to create inconsistent states there, though