First at all, I met this issue when I worked on custom map in the Cartographer. When I used the smooth tool for the beach, saved the map, and later when I come back in the map, the terrain on the beach has some triangle geometric shapes, and it was far away from the shape what has to be done in editor.
I tried to investigate this problem via Steam forums, and got to know that I’m not alone who getting this: Cartographer not saving :: Stranded Deep General Discussions I wish to add more links to the similar posts, but I have some limits as a newcomer here
Somehow, I didn’t found any mention about this issue here, at this forum, that’s why I will try to describe this problem here in a case if the devs will response.
From what I learned now, this vanishing of smoothing effect for the terrain happens not only with editing the new custom map, but also to the previous old custom maps which was done in Cartoghapher before in a previous build of the game (check for it on any old map from Steam workshop). More then, even if you will load the game and check any default original island, you may see exactly the same ‘sharp triangles’ on its beaches too instead of smooth ground - what is weird cause I well remember, that there was nothing like this before.
I have a theory that after recent update, the game begin to read & save the terrain coordinates incorrect.
As for example, when we apply the smooth effect to the surface, terrain vertexes may gets next values in its height position:
vertex A 5.06
vertex B 5.00
vertex C 4.78
vertex D 4.50
vertex E 4.00
vertex F 3.56
vertex G 3.19
vertex H 3.00
But somehow, while the engine reads the map later in a new game or loading it from over in editor, it cuts height coordinate values to a simple numbers, turning to something like this:
vertex A 5.06 → 5.00
vertex B 5.00 → 5.00
vertex C 4.78 → 4.00
vertex D 4.50 → 4.00
vertex E 4.00 → 4.00
vertex F 3.56 → 3.00
vertex G 3.19 → 3.00
vertex H 3.00 → 3.00
For better understanding please see the next attachment:
Therefore we got ugly triangles & stairs instead of smooth terrain every time, no matter how many effort did we put in fixing it in editor.
Idk if the developers knows about this issue, but this bug exist for a quite long time now. Plus, I remember, there was nothing similar like this in a previous builds, and it’s really terrifying. It makes terrain looks horribly bad on any map in a game now, no matter if this is a custom map or default one.