Scrappy Tutorials

Editing Walls via Mapping Extensions JSON Editing

Today, I’m going to go over the newly implemented features of mapping extensions with wall editing, how you can get started working with them, and how you can streamline this process.

Getting Started

First, you’re going to need to know some important information. If you have any questions on how the walls work, you can go to the readme file here. This page will break down how the walls work, as well as the other features of mapping extensions.

Secondly, you’ll need to know how the walls function in Mediocre Mapper. Because of the way that the walls are read in by mapping extensions, the editor tries to read in the values literally, so they look a little weird. This is what you can expect in the editor:Mapper Walls.png

This is completely normal and you just have to ignore it, but at least the editor doesn’t erase the wall. You can interact with the wall just as you can with any other wall, which will save a lot of time copy pasting rather than json editing more walls in.

Lastly, you’ll probably want a text editor other than notepad. I use Sublime text, although I’m sure there are many more out there that will be useful. When it comes to formatting the json file, you can use this website to format the file neatly. This website will also indicate if you made any errors in the file and where that error is.

Constructing The Walls

The following picture will show all the fields in constructing the wall, and I’ll explain them all after.

Wall Info

Making walls that don’t change starting height is pretty easy, and doesn’t require any fancy math skills.

The time represents where the wall is on the grid in mediocre mapper.

The lineIndex represents which column the wall starts at. With mapping extensions you can start the wall outside of the normal 0 – 3 range the base game supports. Walls start from left to right, so if you are visualizing one wall coming from the left and one coming from the right, you have to start the right wall one lineIndex back.

The type represents the height of the wall, and the value will be between 1000 – 4000. 1000 is a wall of height 0, 2000 is a full height wall, and it goes up from there. This will change slightly when changing start height but I’ll get to that later.

The duration is just how long the wall lasts in beats, nothing fancy here.

The Width represents how wide the wall is and starts at a value of 1000. It increments the same as type, so 2000 is a width of 1, 3000 is a width of 2, etc.

Changing Wall Starting Height

Now to the more advanced section, changing the starting height of the wall has a formula which is listed in the readme. It goes all follows –

type = wall Height * 1000 + start height + 4001
//Example for a wall height of 2300 and a start height of 300
type = 2300 * 1000 + 300 + 4001 = 2304301


Wall Height for this is slightly different than before. This time, 1000 corresponds to a wall of height 1, 2000 is height 2, etc.

Start Height is a value between 0 – 999. To understand how start height corresponds to actual values in game, you can watch this video I made which gradually increases the start height values from 1 – 999. As you can see, the increase is very gradual, and the start height corresponds to just about 4 times more than the value says. So, a start height of 300 would be at about 1200 height in game.

Closing Remarks

Walls of width 0 do not seem to break combo in game so you can use those freely. If you use them correctly, you can add a neat curtain effect that the player will see as the wall passes them. It’s harder to see this effect watching back the video but it’s very apparent in game and can add a lot to the music.

If you want some real examples of these walls you can play and look at my map Mujinku-Vacuum Track#ADD8E6- in the json file to see exactly how I made the walls. I’ll be releasing a new map soon called Furry Cannon which will implement the newly added start height change, so you can look at that as an example once released.


If you are not aware with the ranking criteria, this will most likely make your map unrankable. I’m not sure exactly how it works so if you care about rankability it’s best to avoid using this.

Thanks for reading the guide! I hope you can use these tricks to add more to the expression of your maps like I am.


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