TileSetMaker: Procedural Tilesets for 2D Games

TileSetMaker: Procedural Tilesets for 2D GamesTileSetMaker is a tool for creating tilesets—collections of small, reusable images used to build 2D game levels. When combined with procedural generation techniques, TileSetMaker becomes a powerful workflow component that can save time, increase variety, and help small teams or solo developers produce large, cohesive game worlds. This article explains what procedural tilesets are, why they matter, design and technical considerations, workflows using TileSetMaker, integration tips for common engines, performance and memory trade-offs, and examples and best practices.

What are procedural tilesets?

A tileset is a grid-based collection of sprites (tiles) representing building blocks: ground, walls, corners, decorations, and transition pieces. Procedural tilesets are tilesets designed with generation rules in mind—tiles include metadata, rules, or geometry that allow an algorithm to combine them into coherent maps during runtime or in an editor.

Key differences from hand-made tilesets:

• Hand-made tilesets are crafted tile-by-tile for specific maps; procedural tilesets are authored to be combinable by algorithms.
• Procedural tilesets often include additional variants, orientation-aware pieces, and edge rules to support automatic tiling and transitions.
• Metadata (tags, edge masks, collision data) is integral to procedural tilesets.

Why it matters: procedural tilesets reduce repetitive manual work, enable huge or infinite map generation, and produce diverse environments from compact authoring input.

Core components of a procedural tileset

1. Tile topology and alignment

   • Consistent grid size and anchor points.
   • Rules for rotation/mirroring and how tiles connect at edges and corners.

2. Edge rules and transitions

   • Edge tiles that blend between terrain types (e.g., grass-to-dirt).
   • Corner/inner-corner/outer-corner tiles to avoid visual seams.

3. Variants and randomness

   • Multiple visual variants for the same logical tile to reduce repetition.
   • Weighted selection and regional constraints.

4. Metadata and rule definitions

   • Tags (e.g., “water”, “deep”, “shore”), connectivity masks, or adjacency matrices.
   • Collision shapes, object-spawn hints, and layer ordering.

5. Autotiling systems

   • Binary-tile autotiling (based on 8 neighbors) and Wang tiles for color/terrain transitions.
   • Rule- or graph-based tiling (e.g., Wave Function Collapse, constraint solvers).

Designing tilesets for procedural use

Designing with procedural generation in mind influences both art and data structure.

• Plan for modularity: separate base tiles, transition tiles, and decorative overlays. This lets algorithms combine core terrain with localized detail.
• Create edge-compatible artwork: ensure lighting, shading, and texture flow across tile boundaries.
• Provide clear variants: label and include purpose for each variant (e.g., “grass_plain_01”, “grass_rock_02”).
• Include neutral or filler tiles: background tiles, noise masks, and small props that help disguise repetition.
• Design scalable palettes: create variations that work under color shifts or palette swaps to generate biome diversity from the same tileset.

Example: A forest tileset might include base grass tiles, multiple grass tile variants, dirt paths, path-edge tiles, tree stumps and small rocks, transition tiles for water and cliff edges, and scattered foliage overlays.

Autotiling approaches you can use with TileSetMaker

1. Binary (8-bit) autotiling

   • Each tile decides its sprite based on the occupancy of neighboring tiles (8 neighbors → 256 combinations, typically reduced).
   • Good for simple terrain transitions and quick implementations.

2. Wang tiles

   • Edge-based coloring approach where each edge (or vertex) has a type; matching edges creates consistent seams.
   • Efficient for mixing multiple terrain types and handling more than two terrains.

3. Rule-based tiling

   • Explicit rule sets that map specific neighbor patterns to chosen tiles.
   • Flexible and deterministic; useful for handcrafted rules (e.g., rivers, roads).

4. Wave Function Collapse (WFC)

   • Constraint-propagation algorithm that stitches tiles together by respecting local adjacency constraints derived from sample tiles.
   • Great for generating variation while preserving global style, but requires careful tile metadata.

5. Graph/grammar-based generation

   • Uses higher-level procedural rules (graphs, L-systems) to place specialized tiles or room templates—often combined with autotiling for finishing.

TileSetMaker workflow: from authoring to map generation

1. Author tileset

   • Draw/art tiles at consistent tile size (e.g., 16×16, 32×32).
   • Group tiles into categories: base, edges, corners, objects, overlays.
   • Add metadata: tags, adjacency masks, collision bounds.

2. Define tiling rules

   • Choose an autotiling strategy (binary, Wang, WFC, or custom rules).
   • Create rule definitions in TileSetMaker: which tags match, allowed rotations, variant weights.

3. Generate test maps

   • Use TileSetMaker’s preview or export to generate sample maps.
   • Adjust visuals and rules based on seams, unnatural repetition, or gameplay issues.

4. Export tileset and rules

   • Export spritesheets, atlas metadata (UVs), collision data, and rule definitions in a format your engine supports (JSON, Tiled TSX, Unity ScriptableObject, Godot .tres, etc.).

5. Integrate into engine

   • Import atlas and rule files; set up runtime autotiling or tilemap layers.
   • Use procedural map generators (cellular automata, BSP, Perlin noise, or graph-based approaches) to build map structure, then apply autotiling to finalize visuals.

Integration tips for popular engines

• Unity (Tilemap)

  • Use the Tilemap system with RuleTiles (or custom scripts) and import TileSetMaker’s atlas and rule JSON.
  • For optimized performance, bake large static maps into a single sprite atlas or chunked tilemaps.

• Godot

  • Import as a TileSet resource (.tres) or generate tiles from an atlas on load.
  • Use Godot’s autotile support or a WFC plugin; Godot’s collision shapes can be set per-tile.

• Tiled Map Editor

  • Export a TSX file and tileset image for use in Tiled; use object layers/rules to store metadata.
  • Tiled works well for level-design workflows where procedural exporters convert Tiled maps to runtime data.

• Phaser / HTML5

  • Export spritesheets and JSON mappings; implement client-side autotiling or server-side generation and send tile data.

Performance and memory considerations

• Atlas vs. individual textures
  • Use a single atlas for many tiles to reduce draw calls. Keep atlas size within GPU limits.
• Chunking
  • Split large maps into chunks (e.g., 32×32 tile regions) and cull offscreen chunks to reduce rendering and physics load.
• Variant count trade-offs
  • More variants = less visual repetition but more memory. Use shader-based color perturbations to increase perceived variety with fewer sprites.
• Runtime tiling computation
  • Precompute tile indices when possible (during level load or bake step) rather than recomputing every frame.
• Collision optimization
  • Merge adjacent solid tiles into larger collision shapes to reduce physics bodies.

Examples and case studies

• Small indie RPG: used TileSetMaker to author 3 biome sets (grass, desert, swamp). Each biome included 6 base variants × edge tiles × decorative overlays. Procedural dungeon generator produced large overworld maps by stamping biome patches and then applying Wang tiling rules for clean transitions.
• Roguelike: combined WFC-derived “room” templates with binary autotiling for corridors and walls. TileSetMaker supplied tile variants and metadata; runtime selection used weighted randomness to diversify runs.
• Platformer: TileSetMaker output included one-way platforms and slope tiles with precise collision polygons. Procedural level flow used grammar rules for platform placement, then applied autotiling for visual polishing.

Best practices and troubleshooting

• Test seams at multiple scales: view tile joins at 1× and 4× zoom to catch subtle mismatches.
• Start simple: implement basic autotiling first, then add Wang or WFC if you need multi-terrain mixing.
• Use separate layers for gameplay and visuals: keep collision and interaction on one layer and decorative overlays on another to avoid logic-graphic coupling.
• Automate QA: write small scripts to validate adjacency rules and detect orphaned tiles or unreachable terrain types.
• Version your tilesets: small tweaks to a tile’s art can require rebaking maps—use versioning so old maps remain reproducible.

Resources and further reading

• Autotiling algorithms: binary autotile, Wang tiles, and Wave Function Collapse primers.
• Engine docs: Unity Tilemap RuleTile, Godot TileSet and autotile, Tiled map format.
• Procedural generation patterns: cellular automata, BSP dungeons, perlin noise for biome maps.

TileSetMaker, when used with procedural techniques, empowers developers to create large, varied, and coherent 2D worlds from compact authoring input. Designing tilesets with clear metadata, edge rules, and variant strategies makes automated composition reliable and attractive, while mindful integration and performance work keeps projects playable across devices.