But, even if you define 'Types/Animation4Way' with the proper directional keys and animation definitions, you will find 'assembling-machine' ignores this data and just defaults to the north view, with no rotation available.north
Type: Types/Animation
Optional. If omitted, the game will not look for any other directions and instead try to load the whole definition as one Types/Animation and apply it to all directions.
east
Type: Types/Animation...
Weirdly...
Adding the key 'fluid_boxes' to the 'assembling-machine' definition, EVEN IF EMPTY, corrects the issue. (rotations return, rotation events are raised, etc)
There is apparently some logic checking for 'fluid_boxes' and only if it's found does it load the rest of the directional animations.
Links :
https://wiki.factorio.com/Types/Animation4Way
https://wiki.factorio.com/Prototype/Cra ... #animation
Thanks for your time