PolyBash

PolyBash takes a spline and builds stairs, paths, bridges and buildings along it, and generates tileable, recolorable textures for them from 3D blocks.

Key features

• Spline-driven procedural geometry built on the Unity Splines package
• Instant full rebuild on spline edit or inspector change
• Output as standard GameObjects with meshes, materials and mesh colliders
• Save to Prefab: save the generated meshes and materials as a standalone prefab
• Modular stage pipeline where each optional stage can be toggled on or off
• Per-knot corridor widths and per-section overrides
• Scene handles for editing openings in the Scene view
• Info section that reports build results and warnings, such as steps outside your limits
• Designed for creating assets in the Editor, but built for working at Runtime in the future

Spline Stair Path Generator

• Automatic stair vs. flat path classification from spline slope
• Min/max step height and depth limits with tolerance warnings
• Side walls with per-knot base offsets and wall openings
• Tunnels with arch frames
• Edge trims and handrails
• Balusters and newels with per-side and per-section control
• Mesh colliders, plus optional smooth ramp colliders with a bottom wedge
• Arc-length UV mode for consistent texture scale on curves

Spline Building Generator

• Multiple levels, with top and bottom levels set per section
• Outer walls, inner walls, floors, ceilings and top caps
• Gable roof with eave and end overhangs, clipped against taller runs, with roof collider modes
• Doors, windows, floor openings and wall openings
• Generated window frames, panes, door frames and door leaves with adjustable pivots
• Door knob prefab and double inserts
• Separate materials for every part, with a fallback Default Material

Texture generation

• Four texture definitions: Wall, Path, Stair and Roof Tile
• Captures Albedo, AlbedoLit, Normal and Ambient Occlusion maps as PNG files
• Tileable output with wrapped offsets and wrapped occlusion
• Reproducible seeded random layouts
• Live preview using RenderTextures
• Creates a lit material for the active render pipeline (URP, HDRP, or Built-In)

Surface variants

• Gradient-map recoloring in LAB color space
• Two target gradients with an interpolation slider
• Extract a palette from an existing texture
• Save a recolored texture to disk
• Texture Definition Applier and Surface Variant Applier components link the materials to the generators

Included content

• 9 texture definitions (walls, floor, trim, wood path, roof tiles, blue and red wood siding, stairs)
• Surface variants in stone, wood and roof colors
• Block prefabs with normal maps: 9 bricks, 9 worn stones, 3 wooden boards, 9 beveled and 9 jagged roof tiles
• Stone and wood surface texture sets (base color, normal, AO, height, roughness)
• Door knob prefab and FBX models
• BridgeHouse sample scene and two sample prefabs
• Full documentation

Compatibility

• Unity 2022.3 and Unity 6
• URP, HDRP and Built-In Render Pipeline
• Requires com.unity.splines 2.8.4, com.unity.collections 2.6.8, com.unity.burst 1.8.29, com.unity.mathematics 1.3.2, and com.unity.shadergraph 14.0.12
• The Physics Material fields require Unity 6 or newer

Third-party

• Includes Clipper2 (Boost Software License 1.0) and Cutear (ISC License). See Third Party Notices.md in the package.

Documentation | Discord | Email

PolyBash turns Unity splines into level geometry. Draw a spline, and PolyBash builds a walkable stair path or a complete building along it. Move a knot and the result rebuilds right away. The output is ordinary GameObjects with meshes, materials and colliders, so it works with standard Unity tools.

Two spline generators

• Spline Stair Path Generator: sections that rise become stairs, and level sections become flat paths. Step heights and depths stay inside the limits you set. Add side walls, tunnels with arch frames, edge trims, handrails, balusters, newels, and smooth ramp colliders for character controllers.
• Spline Building Generator: builds outer and inner walls, floors, ceilings and gable roofs over one or more levels. Define door, window, and floor openings, and then generate frames, glass panes, and door leaves to fill them.
• Texture generation from 3D blocks: A Texture definition lays out bricks, stones, boards or roof tiles and captures them into tileable albedo, lit albedo, normal and ambient occlusion maps, then creates a material for you. Surface variants recolor the blocks through two gradients, so one set of blocks gives stone, brick, wood siding and roof tile in many color schemes. Drag a slider and the generator updates with the new colors.
• Customizable and genre-flexible: Every width, height, level, opening and material is editable, and optional stages turn on and off with a checkbox. Bake a finished result into a standalone prefab with Save to Prefab. PolyBash suits fantasy villages, medieval towns, stylized and low-poly worlds, platformers, dungeons, bridges, and quick greyboxing for any genre.

The included BridgeHouse sample scene shows two houses on a bridge with stairs, ready to explore in URP, HDRP or the Built-In Render Pipeline.