I made a video guide on how to make a map here: https://youtu.be/-zzxjrVTisM

Sorry for the Poor Quality of audio but im currently temp setup in my kitchen while i get my office sorted

Firstly go to Steam and right click on the game and go to properties and click on it



the click on the Set Launch Options.. Box



Then is the Box that opens up type "-modding" without the Quotes



the close out of all the windows that you opened in steam and launch the game as normal once the game is open and you hit the menu screen select the Modding Option



the in then on the next screen select Map Editor



in the next screen it will display all the maps in your maps folder including ones you have made (if any) I WOULD NOT RECOMMEND YOU EDIT THE GAMES MAPS any edits you make are instantly saved and you could brake then im also not aware of a way to duplicate and rename a map so you can edit an in game map

To Create a map Click New Map in the top left corner



This windows window will then appear



MAP NAME:
Firstly Choose a name for your map

MAP SIZE:
DONT USE 1024 (12 km) the wiki says its not in use and could crash or cause issues

TERRAIN SYNTH TYPE:
ONLY SELECT - Terrain Synth 1 the others will cause issues

CELL SIZE:
USE 400 the others cause crashes and instability within the editor

TERRAIN TYPE:
Select any you like depending on the theme your going for this can be change later inside the editor

LIGHT ENVIROMENT:
Again Choose what you like

SKY BACKGROUND:
Again Choose What you like

When pressing the OK in the bottom right click the lower half or the button so no to change the sky background you chose as it overlaps one of the sky background options

After you press OK a screen like the Following will Load