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Tutorial 4: Validating Your World with Diagnostics

In this tutorial, you will learn how to use the Map Diagnostics tool to ensure your generated caves or dungeons are actually traversable by a player.

The Scenario​

You have generated a cave system using Tutorial 1, but you want to be 100% sure that the player can walk from the entrance to the exit without getting stuck behind a wall of procedural noise.

Step 1: Open the Tool​

  1. Generate your world in the scene.
  2. Go to Window > Dynamic Dungeon > Map Diagnostics.
  3. Click Add Selected to link your WorldGenerator object to the tool.

Step 2: Define "Walkable"​

We need to tell the tool which tiles are solid.

  1. In the Walkability Rules section, enable Auto-Block Collider Tilemaps.
  2. If your walls don't have colliders yet, enable Use Tilemap Layer Rules:
    • Add your Walls layer.
    • Set the mode to Block Any.

Step 3: Test a Path (A*)​

  1. Set the Active Tool to AStar.
  2. Click the Pick Start button. In the Scene View, click on the floor where the player starts.
  3. Click the Pick End button. Click on the floor where the exit should be.
  4. Click RUN DIAGNOSTIC.

Interpreting the Result​

  • If a Green Line appears, the path is valid!
  • If the console says "Path Not Found", your generation logic has created a blocked path. You may need to adjust your noise threshold or cellular automata iterations.

AStar Diagnostic

Step 4: Check for Islands (Flood Fill)​

Isolated islands are areas the player can see but never reach.

  1. Change the Active Tool to Flood Fill.
  2. Ensure your Start point is in the main playable area.
  3. Click RUN DIAGNOSTIC.
  4. A heatmap will appear. Any area that remains grey/uncoloured is unreachable.

Flood Fill Diagnostic

Step 5: Distance Analysis (BFS)​

The BFS tool allows you to visualise the "depth" of your map and confirm reachability from a specific point.

  1. Change the Active Tool to Bfs Heatmap.
  2. Ensure your Start point is set.
  3. Click RUN DIAGNOSTIC.
  4. A colour gradient will appear:
    • Blue/Cyan: Cells very close to the start.
    • Yellow/Red: Cells far away (high travel cost).
    • Grey: Completely unreachable.

This is excellent for checking if your "Exit" is actually a challenging distance away from the "Spawn" point.

BFS Heatmap Diagnostic

Optimisation Tip​

If your generation is large (e.g., 500x500), diagnostics can take a few seconds.

  • Enable Use Physics for faster checks if you have a CompositeCollider2D on your tilemap.
  • The grid is cached; you only need to click Force Rebuild Grid if you manually paint tiles or change the world dimensions.