MV3D is a 3D rendering plugin for RPG Maker MV.
It requires your MV to be version 1.6.1 or newer.
You can download the demo project from github. https://github.com/Dread-chan/MV3D/archive/master.zip
To add MV3D to a new or existing project, download plugin.zip and extract the files into your project directory. Then, load mv3d.js as a plugin via the plugin manager.
Now when you run your game, the map should be rendered in 3D.
There is, of course, a need for some customization. For instructions on those, please read the documentation.
There is a second more detailed, wikia-like version being worked on.