The Overload Level Editor is the custom level editor tool used to build all the levels in Overload. Now you can use it to build custom levels for Campaign (aka Singleplayer) and Challenge Mode. Also includes the optional DMesh Editor for creating custom geometry decal meshes.
The level editor and DMesh editor are two 3D modeling programs that create specialized geometry data. The DMesh editor generates data used by the level editor for geometry decal meshes, while the level editor lets you build levels out of segments (aka deformed cubes). These levels can be exported and used in Challenge Mode or Campaign Mode (aka singleplayer). Custom level support in multiplayer is coming later this year.
There is a learning curve associated with any 3D modeling program, so it is recommended to read the accompanying documentation. We will also have a series of tutorial videos to help learn the editors, and you should use the Steam forums (or Discord) to get assistance or discuss issues.
The Editor comes with both the Steam and GOG versions, but is Windows only. Please note, while the editor is a second application on Steam, it is included in the game application on GOG.