/procedural-generation
Use when implementing procedural generation — noise-based terrain, BSP dungeons, cellular automata caves, wave function collapse, and seeded randomness in Godot 4.3+
$ npx -y skills add jame581/GodotPrompter --skill procedural-generation --agent claude-codeHow it fires
How this skill gets triggered: by you, by Claude, or both.
- Fires itselfAuto-invocation. Claude auto-loads it when your prompt matches the work.Auto-invocation is when the right skill fires by itself at the right moment, driven by a FLOW.md router and a hook, instead of you invoking it by name. It is the difference between a skill being installed and a skill actually getting used.Read the full definition →
- You can call itInvoke it directly when you want it.
- Slash command
/procedural-generation
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The summary Claude sees to decide when to auto-load this skill.
Use when implementing procedural generation — noise-based terrain, BSP dungeons, cellular automata caves, wave function collapse, and seeded randomness in Godot 4.3+
SKILL.md
procedural-generation.SKILL.mdname: procedural-generation
description: Use when implementing procedural generation — noise-based terrain, BSP dungeons, cellular automata caves, wave function collapse, and seeded randomness in Godot 4.3+
Procedural Generation in Godot 4.3+
All examples target Godot 4.3+ with no deprecated APIs. GDScript is shown first, then C#.
> **Related skills:** **2d-essentials** for TileMapLayer usage, **3d-essentials** for 3D terrain meshes, **math-essentials** for vectors and transforms, **godot-optimization** for chunk loading and performance.
---
1. Seeded Randomness
Always use seeds for reproducible generation. This enables shareable seeds, replay, and deterministic testing.
GDScript
# RandomNumberGenerator — per-instance, seedable
var rng := RandomNumberGenerator.new()
func generate_level(level_seed: int) -> void:
rng.seed = level_seed
var width: int = rng.randi_range(20, 40)
var height: int = rng.randi_range(15, 30)
var enemy_count: int = rng.randi_range(3, 8)
var treasure_chance: float = rng.randf_range(0.05, 0.15)
# AVOID: Global randf()/randi() — not reproducible across calls
# USE: rng.randf(), rng.randi(), rng.randf_range(), rng.randi_range()C#
private RandomNumberGenerator _rng = new();
public void GenerateLevel(ulong levelSeed)
{
_rng.Seed = levelSeed;
int width = _rng.RandiRange(20, 40);
int height = _rng.RandiRange(15, 30);
int enemyCount = _rng.RandiRange(3, 8);
float treasureChance = _rng.RandfRange(0.05f, 0.15f);
}> **Tip:** Generate a seed from a string for shareable level codes: `var seed: int = "MyLevel".hash()`
---
2. Noise-Based Generation (FastNoiseLite)
`FastNoiseLite` for height maps, biome distribution, 2D terrain. Key params: `noise_type` (Perlin / Simplex / Cellular / Value), `frequency` (lower = larger features), `seed`. For terrain, sample noise at each tile coord, threshold the value to pick a tile.
> See [references/noise-generation.md](references/noise-generation.md) for the basic noise-map recipe, noise-type reference table, and 2D terrain + TileMapLayer walkthrough.
---
3. BSP Dungeon Generation
Binary Space Partitioning recursively splits a rectangle into smaller rectangles, carves a room inside each leaf, connects siblings with corridors. Produces grid-aligned room-based dungeons (think roguelike).
> See [references/bsp-dungeons.md](references/bsp-dungeons.md) for the full recursive partition + room placement + corridor connection algorithm in GDScript + C#.
---
4. Cellular Automata (Cave Generation)
Fill a grid with random walls/floors at ~45% density, then iterate "a cell becomes a wall if ≥ 5 of 8 neighbors are walls" 4-5 times. The result is organic cave shapes — no straight corridors.
> See [references/cellular-automata.md](references/cellular-automata.md) for the full GDScript + C# implementation with TileMapLayer integration.
---
5. Wave Function Collapse (WFC)
WFC is a constraint solver: given a tile set with adjacency rules, pick the lowest-entropy cell, collapse it to a valid tile, propagate constraints, repeat. Produces tile-rule-respecting output but is non-trivial to implement.
> See [references/wave-function-collapse.md](references/wave-function-collapse.md) for concept overview and a simplified GDScript + C# implementation.
---
6. Common Pitfalls
| Symptom | Cause | Fix | |---------|-------|-----| | Same level every time | Not seeding the RNG | Set `rng.seed` before generation | | Different results on different platforms | Using global `randf()` / `randi()` | Use a dedicated `RandomNumberGenerator` instance | | Noise looks blocky | Frequency too high | Lower `frequency` (try 0.01–0.05) | | Caves are all wall or all floor | `fill_chance` too extreme or too few iterations | Use fill_chance 0.40–0.50 and 4–6 iterations | | BSP rooms overlap | Split position too close to edge | Ensure `min_room_size` buffer in split calculation | | WFC contradiction (no valid tile) | Adjacency rules too restrictive | Add more allowed neighbors or implement backtracking | | Generation takes too long | Processing entire map in one frame | Use `await get_tree().process_frame` to spread across frames, or use a thread |
---
7. Implementation Checklist
- [ ] All generation uses a seedable `RandomNumberGenerator`, never global `randf()`/`randi()`
- [ ] Seeds are stored with save data so levels can be reproduced
- [ ] `FastNoiseLite` frequency and octaves are tuned for the game's tile/world scale
- [ ] Large generation is spread across frames or run on a thread to avoid freezing
- [ ] Generated TileMapLayer content uses terrain autotiling when possible (not hardcoded tile coords)
- [ ] BSP dungeons verify all rooms are connected before finalizing
- [ ] Cave generation runs a flood-fill to ensure reachability between key points
- [ ] Player spawn point is validated to be on a floor tile, not inside a wall
Read more
name: procedural-generation description: Use when implementing procedural generation — noise-based terrain, BSP dungeons, cellular automata caves, wave function collapse, and seeded randomness in Godot 4.3+
Procedural Generation in Godot 4.3+
All examples target Godot 4.3+ with no deprecated APIs. GDScript is shown first, then C#.
> **Related skills:** **2d-essentials** for TileMapLayer usage, **3d-essentials** for 3D terrain meshes, **math-essentials** for vectors and transforms, **godot-optimization** for chunk loading and performance.
---
1. Seeded Randomness
Always use seeds for reproducible generation. This enables shareable seeds, replay, and deterministic testing.
GDScript
# RandomNumberGenerator — per-instance, seedable
var rng := RandomNumberGenerator.new()
func generate_level(level_seed: int) -> void:
rng.seed = level_seed
var width: int = rng.randi_range(20, 40)
var height: int = rng.randi_range(15, 30)
var enemy_count: int = rng.randi_range(3, 8)
var treasure_chance: float = rng.randf_range(0.05, 0.15)
# AVOID: Global randf()/randi() — not reproducible across calls
# USE: rng.randf(), rng.randi(), rng.randf_range(), rng.randi_range()C#
private RandomNumberGenerator _rng = new();
public void GenerateLevel(ulong levelSeed)
{
_rng.Seed = levelSeed;
int width = _rng.RandiRange(20, 40);
int height = _rng.RandiRange(15, 30);
int enemyCount = _rng.RandiRange(3, 8);
float treasureChance = _rng.RandfRange(0.05f, 0.15f);
}> **Tip:** Generate a seed from a string for shareable level codes: `var seed: int = "MyLevel".hash()`
---
2. Noise-Based Generation (FastNoiseLite)
`FastNoiseLite` for height maps, biome distribution, 2D terrain. Key params: `noise_type` (Perlin / Simplex / Cellular / Value), `frequency` (lower = larger features), `seed`. For terrain, sample noise at each tile coord, threshold the value to pick a tile.
> See [references/noise-generation.md](references/noise-generation.md) for the basic noise-map recipe, noise-type reference table, and 2D terrain + TileMapLayer walkthrough.
---
3. BSP Dungeon Generation
Binary Space Partitioning recursively splits a rectangle into smaller rectangles, carves a room inside each leaf, connects siblings with corridors. Produces grid-aligned room-based dungeons (think roguelike).
> See [references/bsp-dungeons.md](references/bsp-dungeons.md) for the full recursive partition + room placement + corridor connection algorithm in GDScript + C#.
---
4. Cellular Automata (Cave Generation)
Fill a grid with random walls/floors at ~45% density, then iterate "a cell becomes a wall if ≥ 5 of 8 neighbors are walls" 4-5 times. The result is organic cave shapes — no straight corridors.
> See [references/cellular-automata.md](references/cellular-automata.md) for the full GDScript + C# implementation with TileMapLayer integration.
---
5. Wave Function Collapse (WFC)
WFC is a constraint solver: given a tile set with adjacency rules, pick the lowest-entropy cell, collapse it to a valid tile, propagate constraints, repeat. Produces tile-rule-respecting output but is non-trivial to implement.
> See [references/wave-function-collapse.md](references/wave-function-collapse.md) for concept overview and a simplified GDScript + C# implementation.
---
6. Common Pitfalls
| Symptom | Cause | Fix | |---------|-------|-----| | Same level every time | Not seeding the RNG | Set `rng.seed` before generation | | Different results on different platforms | Using global `randf()` / `randi()` | Use a dedicated `RandomNumberGenerator` instance | | Noise looks blocky | Frequency too high | Lower `frequency` (try 0.01–0.05) | | Caves are all wall or all floor | `fill_chance` too extreme or too few iterations | Use fill_chance 0.40–0.50 and 4–6 iterations | | BSP rooms overlap | Split position too close to edge | Ensure `min_room_size` buffer in split calculation | | WFC contradiction (no valid tile) | Adjacency rules too restrictive | Add more allowed neighbors or implement backtracking | | Generation takes too long | Processing entire map in one frame | Use `await get_tree().process_frame` to spread across frames, or use a thread |
---
7. Implementation Checklist
- [ ] All generation uses a seedable `RandomNumberGenerator`, never global `randf()`/`randi()`
- [ ] Seeds are stored with save data so levels can be reproduced
- [ ] `FastNoiseLite` frequency and octaves are tuned for the game's tile/world scale
- [ ] Large generation is spread across frames or run on a thread to avoid freezing
- [ ] Generated TileMapLayer content uses terrain autotiling when possible (not hardcoded tile coords)
- [ ] BSP dungeons verify all rooms are connected before finalizing
- [ ] Cave generation runs a flood-fill to ensure reachability between key points
- [ ] Player spawn point is validated to be on a floor tile, not inside a wall
Agentic skills framework for Godot 4.x game development. Gives AI coding agents domain-specific expertise for GDScript and C# projects.
Other skills on godot-prompter.
- /authoring-godot-prompter-skills
Use when writing or editing a SKILL.md or an agent definition in this repo — required frontmatter, section ordering, and the GDScript-then-C# example convention.
Open skill - /releasing-godot-prompter
Use when cutting a GodotPrompter release or bumping its version — the version-bump sequence, tag-triggered workflow, and the marketplace manifests that must follow.
Open skill - /2d-essentials
Use when working with 2D-specific systems — TileMaps, parallax scrolling, 2D lights and shadows, canvas layers, particles 2D, custom drawing, and 2D meshes in Godot 4.3+
Open skill - /3d-essentials
Use when working with 3D-specific systems — materials, lighting, shadows, environment, global illumination, fog, LOD, occlusion culling, and decals in Godot 4.3+
Open skill - /ability-system
Use when building character abilities — Resource-based abilities with cost/cooldown/cast, buffs/debuffs, stat modifiers, gameplay tags, and HUD binding
Open skill - /addon-development
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Open skill