[Project] Pywow Reborn – Solo AzerothCore Server (Playerbots / YAML & mmaps issues)

[kristofe31]

Hi everyone,

I’m working on a custom solo AzerothCore 3.3.5a project called Pywow Reborn.
It’s a personal revival of a server where I spent some of my best moments years ago — so my goal is to rebuild it and make it playable solo with Playerbots.

However, after several attempts using the Playerbot branch (Liyufan) and recent commits, I ran into the same issue three times:

🧩 Current problem

The mmaps_generator included in the branch requires a YAML config file (mmaps-config.yaml),
but it fails to read it properly, even with yaml-cpp correctly installed and linked.

When compiling, everything works fine (no errors, YAML detected), but at runtime:

./mmaps_generator --config ./mmaps-config.yaml
Failed to load configuration. Ensure that 'mmaps-config.yaml' exists...

I’ve tried:

multiple clean rebuilds (with/without yaml-cpp_DIR),

the classic pre-YAML arguments (Data + output),

older mmaps v16 and v17 formats,

and even different forks (Liyufan, Playerbots-Reborn).

Every attempt leads to the same dead end: the generator cannot process YAML configs, and the server refuses old mmaps (v16).

⚙️ Environment

Ubuntu 24.04

GCC 13.3.0

AzerothCore fork (Playerbot branch, Oct 2025)

Docker + XAMPP already working fine

❤️ The goal

To get a fully working Playerbot-enabled AzerothCore again, capable of generating or using mmaps correctly (v17), and allowing solo play with natural bot behavior (PvE + limited PvP).

If anyone is maintaining a pre-YAML Playerbot fork or working on a functional YAML implementation for mmaps_generator, I’d love to collaborate, test, or even help document it.

Thank you all for keeping AzerothCore alive —
I hope Pywow Reborn can one day join the list of functional solo projects again.

— Christophe (Pywow Reborn)

[walkline]

Works fine for me:

~/d/w/ac/azerothcore-clean/cmake-build-d/s/tools ❯ ls
cmake_install.cmake CMakeFiles          map_extractor       mmaps_generator     mmaps-config.yaml
~/d/w/ac/azerothcore-clean/cmake-build-d/s/tools ❯ cat mmaps-config.yaml
mmapsConfig:
  skipLiquid: false
  skipContinents: false
  skipJunkMaps: true
  skipBattlegrounds: false

  # Path to the directory containing navigation data files.
  # This directory should contain the "maps" and "vmaps" folders,
  # and is also where the "mmaps" folder will be created or located.
  dataDir: "/Users/user1/dev/wow/ac-data"

  meshSettings:
    # Here we have global config for recast navigation.
    # It's possible to override these data on map or tile level (see mapsOverrides).

    # Maximum slope angle (in degrees) NPCs can walk on.
    # Surfaces steeper than this will be considered unwalkable.
    walkableSlopeAngle: 60

    # --- Cell Size Calculation ---
    # Many parameters below are defined in "cell units".
    # In RecastDemo, you often work with world units instead of cell units.
    # By default, these cell units are converted to world units using the formula:
    #
    #     cellSize = MMAP::GRID_SIZE / (verticesPerMapEdge - 1)
    #
    # Where:
    #     MMAP::GRID_SIZE = 533.3333f (the size of one map tile in world units)
    #     verticesPerMapEdge = number of vertices along one edge of the full map grid
    #
    # Example:
    #     If verticesPerMapEdge = 2000, then:
    #         cellSize ≈ 533.3333 / (2000 - 1) ≈ 0.2667 world units per cell
    #
    # To convert a value from cell units to world units (e.g., walkableClimb),
    # multiply by cellSize. For example, a walkableClimb of 6 corresponds to:
    #     6 * 0.2667 ≈ 1.6 world units

    # Minimum ceiling height (in cell units) NPCs need to pass under an obstacle.
    # Controls how much vertical clearance is required.
    # To convert to world units, multiply by cellSize (see "Cell Size Calculation").
    walkableHeight: 6

    # Maximum height difference (in cell units) NPCs can step up or down.
    # Higher values allow walking over fences, ledges, or steps.
    # To convert to world units, multiply by cellSize (see "Cell Size Calculation").
    #
    # Vanilla WotLK uses 6, which allows creatures to "jump" over fences.
    # Classic WotLK uses 4, which forces creatures to walk around fences.
    walkableClimb: 6

    # Minimum distance (in cell units) around walkable surfaces.
    # Helps prevent NPCs from clipping into walls and narrow gaps.
    # To convert to world units, multiply by cellSize (see "Cell Size Calculation").
    walkableRadius: 2

    # Number of vertices along one edge of the entire map's navmesh grid.
    # Higher values increase mesh resolution but also CPU/memory usage.
    verticesPerMapEdge: 2000

    # Number of vertices along one edge of each tile chunk.
    # Must divide (vertexPerMapEdge - 1) evenly for seamless tiles.
    # A higher vertex count per tile means fewer total tiles,
    # reducing runtime work to load, unload, and manage tiles.
    verticesPerTileEdge: 80

    # Tolerance for how much a polygon can deviate from the original geometry when simplified.
    # Higher values produce simpler (faster) meshes but can reduce accuracy.
    maxSimplificationError: 1.8

    # You can override any global parameter for a specific map by specifying its map ID.
    # Inside each map override, you can also override parameters per individual tile,
    # identified by a string "tileX,tileY" (coordinates).
    #
    # Overrides cascade: global settings → map overrides → tile overrides.
    # For example:
    #
    # mapsOverrides:
    #   "0":                              # Map ID 0 overrides
    #     walkableRadius: 5               # Override global climb height for entire map 0
    #
    #     tilesOverrides:
    #       "50,70":                      # Tile at coordinates (50,70) on map 0
    #         walkableSlopeAngle: 70      # Override slope angle locally just here
    #         walkableClimb: 4            # Also override climb height for this tile only
    #
    #       "51,71":
    #         walkableClimb: 3            # Override climb height for tile (51,71)
    #
    #       "48,32":
    #         walkableClimb: 1            # Even smaller climb for tile (48,32)
    #
    #   "1":                              # Map ID 1 overrides example
    #     walkableHeight: 8               # Increase clearance for whole map 1
    #
    #     tilesOverrides:
    #       "100,100":
    #         maxSimplificationError: 2.5 # Looser mesh simplification for this tile only
    #
    #       "101,101":
    #         walkableRadius: 1           # Smaller NPC radius here for tight corridors
    #
    # This approach allows very fine-grained control of navigation mesh parameters
    # on a per-map and per-tile basis, optimizing pathfinding quality and performance.
    #
    # All parameters defined globally are eligible for override.
    # Just specify the parameter name and new value in the override section.
    mapsOverrides:
      "562": # Blade's Edge Arena
        walkableRadius: 0 # This allows walking on the ropes to the pillars

      "48": # Blackfathom Deeps
        cellSizeVertical: 0.5334 # ch*2 = 0.2667 * 2 ≈ 0.5334. Reduce the chance to have underground levels.

      "529": # Arathi Basin
        tilesOverrides:
          "30,29": # Lumber Mill
            # Make sure that Fear will not drop players rom cliff -
            # https://github.com/azerothcore/azerothcore-wotlk/pull/22462#issuecomment-3067024680
            walkableSlopeAngle: 45

  # debugOutput generates debug files in the `meshes` directory for use with RecastDemo.
  # This is useful for inspecting and debugging mmap generation visually.
  #
  # My workflow:
  # 1. Install RecastDemo. I'm building it from the source of this fork: https://github.com/jackpoz/recastnavigation
  # 2. In-game, move your character to the area you want to debug.
  # 3. Type `.mmap loc` in chat. This will output:
  #    - The current tile file name (e.g., `04832.mmtile`)
  #    - The Recast config values used to generate that tile
  # 4. Enable `debugOutput` and regenerate mmaps (preferably just the tile from step 3).
  #    - To regenerate only one tile, delete it from the `mmaps` folder.
  # 5. After generation, you will find debug files in the `meshes` folder, including an OBJ file (e.g., `map0004832.obj`)
  # 6. Copy these debug files to the `Meshes` folder used by RecastDemo.
  #    - RecastDemo expects this folder to be in the same directory as its executable.
  # 7. In RecastDemo:
  #    - Click "Input Mesh" and select the `.obj` file
  #    - Choose "Solo Mesh" in the Sample selector
  # 8. (Optional) Reuse the Recast config values from step 3:
  #    - `cellSizeHorizontal` → "Cell Size"
  #    - `walkableSlopeAngle` → "Max Slope"
  #    - `walkableClimb` → "Max Climb"
  #    - and so on
  # 9. Scroll to the bottom of RecastDemo UI and press "Build" to generate the navigation mesh
  debugOutput: false
  
~/d/w/ac/azerothcore-clean/cmake-build-d/s/tools ❯ ./mmaps_generator --config ./mmaps-config.yaml
Discovering maps... found 105.
Discovering tiles... found 6035.

Using 14 threads to generate mmaps
[Map 000] Creating navMesh...
[Map 000] We have 687 tiles.
0% [Map 0000] Building tile [24,54]
0% [Map 0000] Building tile [25,23]
0% [Map 0000] Building tile [25,22]
0% [Map 0000] Building tile [25,24]
0% [Map 0000] Building tile [24,55]
0% [Map 0000] Building tile [24,53]
0% [Map 0000] Building tile [25,25]
0% [Map 0000] Building tile [25,28]
0% [Map 0000] Building tile [25,32]
0% [Map 0000] Building tile [25,31]
0% [Map 0000] Building tile [25,30]
0% [Map 0000] Building tile [25,27]
0% [Map 0000] Building tile [25,26]
0% [Map 0000] Building tile [25,29]
[Map 571] Creating navMesh...

Can you provide the same output?

[kristofe31]

Hey,

I just wanted to sincerely thank you for sharing your full mmaps-config.yaml.
You have no idea how much time and frustration you just saved me — I’ve been stuck for over a week trying to get the mmaps generator to work properly with the Playerbot (Liyufan) fork, constantly hitting YAML parsing errors.

Your config file was the missing piece.
As soon as I used it, everything finally clicked — the generator is now running perfectly and building tiles without a single issue.

Really, thank you for taking the time to post that example and keep AzerothCore alive.
You’ve just put an end to days of headaches and made one more happy solo dev out there 😄

— Christophe (Pywow Reborn)