Developer's notes

Current (priority)

• (now): Volume refactoring
• (todo next): Simulation as a json file

Next steps:

• visualisation of voxelized volume with 3D slices
• Refactor sources
• Refactor actors
• Consolidate: Simulation user API and rename geometry_manager
• Retrieving repeated volumes of detailed information (position etc), once built. Important for PET design
• Consolidate subprocess system: handle subprocessing in Simulation class (rather than engine)