MV3D

You can download the demo project from each version's itch.io page.
MV3D on itch.io
MZ3D on itch.io

In there you will have a demo version of the plugins, with some functions missing, and a demo project to see it at work.

Fot the full product, you can buy the plugin on the respective itch.io, or become a patron on Patreon.

To add the plugin to a new or existing project:

1. Download the proper plugin zip file, instead of the demo project zip file,
2. Extract the files right inside your project directory.
   The folders are already set to put the needed files on the proper folder.
   (If you are wondering, the files are: the plugin itself to go in js/plugins and a folder with some needed image files to go in the img folder, the folder being MV3D or MZ3D depending on the plugin, and the image files inside being “bushAlpha.png”, “shadow.png” and “errorTexture.png”)
3. Then, load mv3d (mz3d if you are using MZ) as a plugin on 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.
A more detailed, wikia-like version is being worked on. Look at the Sitemap for the individual pages for now.

However, it is heavily advised to download, check and experiment with the demo project. There is no better way to understand how the plugin works than to see for yourselves and play with it a bit, after all.
Adding to that, if you are using MZ3D, it is still advised to download the MV3D demo project, as it has some example maps the MZ3D one does not. To open an MV project in MZ, copy a “game.rmmzproject” file of an MZ project to the MV one's.

And beyond that, there are always tutorials.

Tutorials

Discord
Patreon
MV3D on itch.io
MZ3D on itch.io