The Fourth Dimension​

The first Super Mario 3D land level editor​

UPDATE: Version 0.9.2 out now !​

Warning: Spoilers inside!

Some screenshots:

Features:
-Level loading and object editing
-Rails viewing and editing
-Loading levels from szs,byml or xml
-Converting game models to obj
-Byml <-> xml converter
-Model importer

Things still to be done:
-Better 3D viewer
-other things (?)

What do you need ?
Windows Vista/7/8.1/10 and .Net Framework 4.5.2 (Sorry linux users, but this uses some WPF components for 3d rendering that mono can't run)
The unpacked romfs of the game
A way to run the custom levels (3ds with ntr cfw, hans or citra maybe)
Every file explorer

How to use the editor
Unpack the romfs of the game, then open the editor and select it, the editor will convert every model to obj (so they can be viewed), this will take a while.
Now open a level and you're ready to go !

Some tips
When you zoom in too much the camera may go crazy, zoom out to fix that.
Don't play with the "l_id" value of objects, if there is invalid data the game will crash.
Keep some backups of the level while editing, the editor may crash.
If there are 3D objects that are annoying in the 3D view(skyboxes, TransparentWalls, etc), delete their 3d model in the models folder or rename it, the object will be replaced in the editor with a small blue cube

About the CreatorClassNameTable patching

Thanks to @Gericom for every file explorer and it's DLLs
Thanks to @gdkchan for Ohana3DS

Download: Here
If you never used The4Dimension before i also wrote a guide on the basics of the editor to get you started: here

A custom level made by me:


Other videos:

Warning: Spoilers inside!

@mustafag32g made a video where he explains the basics of the editor:

The old method to import models: