Stylized Sewers Generator for Blender

Builds whole sewer and catacomb levels from the included Stylized Sewers and Catacombs Kit (281 hand painted style pieces): canal tunnels with one connected water network, chambers, reservoir halls, octagon domes, crypts, shafts, props and lights. Python lays out the rooms and tunnels; a Geometry Nodes modifier builds everything you see, live.

Install

Blender 5.2 or newer: Edit > Preferences > Add-ons > Install from Disk, choose the ZIP, enable "Stylized Sewers Generator". The panel is in the 3D Viewport sidebar (N) under Sewers.

The add-on contains the 281 kit pieces at full detail (LOD0) with packed textures, marked as assets in catalogs (Architecture, Water, Lights, Organic, Props). To build by hand, add assets/ inside the add-on folder as an asset library (Preferences > File Paths > Asset Libraries). LOD1 and LOD2, collision meshes and the demo levels are part of the Unreal, Unity and Godot versions of the kit, not of the Blender version.

Use

Add Sewers creates a level at the 3D cursor. Select it to edit it in the panel. Large levels take a few seconds to update after a change.

• Seed: one number for the whole level. The arrow button gives the next seed.

Layout

• Storeys: one storey, or a second one 8 m above, joined by ladder shafts into floor hatches.
• Rooms, Width, Depth, Room Min, Room Max: number and size of rooms and the size of the area, in 4 m cells.
• Start and Exit: marks the two rooms the most tunnels apart, or the outfall.
• Catacombs: share of the map that is catacomb (crypts, dry corridors with burial niches).
• Loops, Junctions, Dead Ends: extra tunnels that close loops, side tunnels that join through T junctions, blind spurs that end in a wall with a culvert and an inflow pipe.
• Outfall: a dead end canal may leave the level through an outfall facade onto a riverbank.
• Wide Collectors: straight 8 m wide tunnels between rooms that face each other.
• Diagonals, Y Forks: canals on 45 degree diagonals, canals that split in a Y chamber into two arms.
• Levels: rooms on deeper floor levels, reached over weirs with waterfalls and dry steps.
• Shafts, Crawl Pipes: manholes with ladders and well shafts, round crawl pipes behind a grille.

Rooms

• Octagon Rooms, Cisterns, Reservoir Hall, Galleries, Canal Halls: how often these room types appear.
• Doors and Hatches: closed doors, secret doors, stairs up to cellar doors, floor hatches, barred cells.

Look

• Props, Wear, Lights, Pipes, Gates and Bridges: amount of dressing, broken pieces, light props, pipes, gates and bridges.

View

• Storey: which storey you see in a two storey level.
• Water, Water Level: water on or off, and its height up to flooded halls.
• Flow Arrows: shows which way the water flows.
• Light Points, Light Strength: point lights at the light props and their strength.
• Cutaway, Cut Height: opens the level from above for top down views.
• Realize: real geometry instead of instances.
• Dark, Torchlit, Murky, Day: light rigs for the scene.

Export (sub panel)

• Make Real: a copy of the level as normal objects (lights stay separate objects).
• Export Level: GLB or FBX, chosen by the file extension, with the instances realized.
• Export Layout JSON: every placed module and light with position and rotation, for rebuilding the level from the kit in a game engine.
• Export VTT Map: top down battle map as PNG plus a Universal VTT file (.dd2vtt) with walls and lights. Options: pixels per square, grid, dark (lit only by the lanterns and torches), flow arrows, storey. One 4 m cell is 3 squares (walkway, canal, walkway).

Fine tuning

The modifier "Stylized Sewers" (Modifier tab) holds the look and view settings, and the node tree is grouped into readable sections. You can change pick lists and rules there if you want to adapt the generator.

Grid

Cells 4 x 4 m on a 0.5 m grid, walls 4 m high, walkway at height 0, canal bed 1 m lower.

Textures

Every texture is generated procedurally by our own Python scripts in Blender. No texture libraries, scans or image generators were used.

License

Code: GPL 3.0 or later. 3D assets: royalty free for your own projects (commercial included), no redistribution as assets.

Made with procedural modelling in Blender with AI assistance (Claude), designed and reviewed by Nico Hartl.