The inheritance structure was introduced by the resolution of T17035 (Platformproject Esther)
Before: The AbstractTransformGeometry was derived from Geometry2D and could not be casted to a PlaneGeometry. This fact was used on multiple places to distinguish the types of the input object.
- in the mitkExtractSliceFilter to handle curved plane geometries differently than regular plane geometries.
- the BaseRenderer in SetWorldGeometry3D
- possibly more places ...
current master: AbstractTransformGeometry inherits the mitk::PlaneGeometry class and can thus be casted to such.