Factorio Forums

Before version 2.X there was a collision-layer that only the out-of-map tile had, called "floor-layer". This could be used to have entities only exist on solid ground or water but not outside of the map (I used it for a car mod, the vehicle could drive both on water and solid ground).
However from 2.0 on, the collision-layer system changed but apparently also did the usage of the now renamed "floor" collision-layer. It is now not only assigned to the out-of-map tile but also the water tiles. The out-of-map tile now doesn't have a standalone collision layer anymore which would make the creation of one by mod creators neccessary. The reason I'm not simply doing that is that I'm not sure if this isn't actually a bug, since the usage was different before, the layer was familiary named and now doesn't really have a standalone use anymore. You can check for collision with water with the water_tile layer and for collision with solid ground with the ground_tile layer. In my eyes a layer for the "void" out-of-map tile is neccessary. I did discuss this matter with Xorimuth on the official Discord here as well.

tl:dr

Entity collision solely with the out-of-map tile is no longer possible without the creation and assigning of a new collision-layer. It was natively possible before in < 2.0 while the new renamed version serves no function according to my observation. If I'm wrong, I am asking for clarification and your forgiveness ^^

Thanks for the report. The changes were intentional and part of the increased complexity of space-age related collisions.