Villevite City Generator

Villevite is a Blender add-on designed to procedurally generate cities for training data synthesis, including buildings, streets with variable width and intelligent crossroad calculation and vegetation. It provides tools for creating realistic urban environments and customization through assets and parameters.

Features

• Procedural generation of cities with buildings, streets, and trees.
• Asset-based architecture for modular and reusable components.
• Integration with Blender's 3D Viewport for real-time visualization.
• Support for generating and managing city elements through a custom UI panel.

Development Setup

Prerequisites

• Blender: The add-on requires Blender 5.2.0 (bundled Python 3.13).
• Python: Python 3.13 is recommended for development.

Setting Up the Development Environment

1. Clone the repository:

   git clone https://github.com/burghain/villevite.git
   cd villevite

2. Initialze the Assets submodule:

   git submodule init
   git submodule update

3. Install the required Python dependencies:

   pip install -r development_requirements.txt

4. Set up Blender to recognize the Villevite Assets:

   • Open Blender.
   • Go to Edit > Preferences > File Paths > Asset Catalogs.
   • Add the absolute path to the ./villevite/Assets directory as an Asset Catalog.
   • Change the import policy to "Link".

Running Tests

Villevite includes a test suite to ensure the functionality of its components. To run the tests:

python ./dev.py test

Usage

The city is generated from a road graph: a plain wire mesh (vertices and edges, no faces) that you build manually. All road attributes (lanes, sidewalks, bike lanes, …) and building floor plans are generated automatically by the GeoCity geometry node group.

1. Open Blender and navigate to the 3D Viewport.
2. Access the Villevite panel from the side toolbar under the "villevite" tab.
3. Use the provided operators:
   • Load Default Road Graph: Appends the starter road graph from the bundled Nodes.blend. Edit it in Edit Mode (or build your own wire mesh from scratch). Note: linked graphs (e.g. "Example Road Graph" from Templates.blend) must be made local before they can be used.
   • Generate City: Attaches the GeoCity modifier to the active (or first valid selected) road graph object — if none is selected, the Default Road Graph is loaded automatically. All generation parameters (seed, probabilities, densities, …) are edited directly on the modifier.
   • Prepare for Scanning: Bakes the city to real objects and extracts the scan paths (runs on a copy, so your road graph is preserved).
   • Clear All: Resets the scene.

Headless generation

With the extension installed into Blender:

blender -b --python generate_city.py -- <output.blend> [<graph.blend> [<object_name>]]

Without a graph file, the city is generated from the bundled Default Road Graph. With a graph file, the object named <object_name> (default: "Road Graph") is used, falling back to the file's active object. prepare_scan.py reads the same options from scan_config.json (road_graph_blend, road_graph_object) or the environment variables ROAD_GRAPH_BLEND / ROAD_GRAPH_OBJECT, e.g. for Docker:

docker run -e ROAD_GRAPH_BLEND=/data/graph.blend -v <host_graphs>:/data ...

Note: the Docker base image still provides the Blender 4.4 scanning toolchain (vLiDAR); only city generation runs on Blender 5.2.0.

Architecture

Assets

• Assets are sorted into different .blend files.
• Each collection that needs to be used individually (e.g., Building Walls) is stored as a separate asset.

City Generator

• The city generator uses procedural algorithms to create realistic urban layouts.

General Add-on Structure

• The add-on follows the structure outlined in the BlenderAddonTemplate.

References

Assets

• The vehicles were selected from the CADillac dataset and can be used under the Creative Commons Public License Version 4.0.
• "Cyclist - racing position - free 3d printable" (https://skfb.ly/6TM97) by Andy Woodhead is licensed under Creative Commons Attribution

Future Work

Potential Additions to the City Generator

• Street Furniture Sidewalk:
  • Bollards, Railings
  • Electrical Boxes
  • Parked Motocycles, Bikes, E-Scooter
  • Bicycle Racks
  • Advertisement Boards
  • Restaurants, chairs & tables
  • Construction sites on strett/ sidewalk
  • Mailboxes
  • Parking Metres
  • Trash cans (on poles, standalone)
  • Pedestrians