How to build tools for Unity

Unity is an incredibly powerful game engine, but building custom editor UIs can be a real pain.

A screenshot showing the labyrinth generator component UI — My custom labyrinth editor - built in the browser, imported as JSON.

A webapp

I decided to try a data-driven approach: vibe-code the labyrinth generator in Javascript, export the map as JSON, and import it into Unity.

A component

The Unity component reads the JSON and places objects accordingly. It also decides which doors to block or show, so I don’t have to design a million pieces. Stole that idea from Lethal Company’s facility doors.

MST Algorithm

An MST (Minimum Spanning Tree) algorithm finds the cheapest way to connect all nodes in a graph without creating cycles. Think of it like connecting cities with roads using the least amount of pavement possible.

Nodes-First

I start by placing rooms on a grid, then use MST to figure out which rooms should connect. But MST only tells me what to connect—not how to draw the hallways between them. That’s where A* pathfinding comes in.

Here’s the process:

Place rooms on the grid
Use MST to determine which rooms connect
Use A* to draw actual hallways between them

A diagram showing how MST connects nodes and A* draws paths between them — MST decides connections, A* draws the hallways.

“Connectedness” slider

I modified the MST algorithm with a slider that controls how “expensive” connections can be:

100% = Rooms connect to their nearest neighbors (cheap, compact)
0% = Rooms connect to distant nodes (expensive, sprawling)

This creates a problem: sometimes hallways need to pass through other rooms. That’s impossible with flat geometry… unless I add verticality.

Deadly Stairs

The only enemy in the labyrinth is the tide—rising water that floods the lower levels. I wanted to make some areas more dangerous by forcing players into confined, maze-like spaces below ground level.

When the water rises, you need to find high ground (a room) to survive.

A screenshot of my labyrinth tool in 3D showing stairways connecting underneath rooms — My labyrinth tool

A screenshot of my labyrinth being rendered in Unity — The same layout in Unity

Piecing together a seamless labyrinth

Placing rooms, running pathfinding—that’s the easy part. The hard part is making a seamless interior that feels cohesive, not like a bunch of disconnected pieces.

This was the most important step: measuring everything precisely so I could stylize it later without gaps or overlaps.

A screenshot showing a seamless labyrinth room — A room on one level

A seamless labyrinth interior with a stairway at the end of a long hallway — The hallways beneath

Filling out the rooms

Fish, statues, urns, and journals

I vibe-coded a “Room Designer” tool—an infinite canvas where I can drag objects around and preview what gets placed in-engine.

There are four things that generate randomly:

Statues — the photo-snappable objectives
Urns — decorative fakes to throw you off
Journals — mysterious lore books
Fish — food (you gotta eat something)

Screenshot of the custom Room Designer tool with draggable objects on an infinite canvas — The Room Designer

Making them prefabs

I added prefabs for each object type, wrote some JSON parsing, and… voilà:

Screenshot of Unity Editor with generated statues, urns, journals, and fish spawned in a labyrinth room — Generated room in Unity

Next steps

There’s still a lot to do with just the labyrinth alone—not to mention the hunger mechanic, the shopkeeper, multiplayer (someday), and the tide itself. Making games is hard!

I need to steel myself and stop polishing the labyrinth until I have a hunger system working. Gotta get my head out of the gutter.