Procedural Building Implementations

A very interesting and valuable approach is to generate buildings automatically, with minimal hand-effort in specifying and locating them.

Existing Tools and Projects

See the CAD Software page for some commercial software for manually designing buildings with some degree of procedural/parametric automation, in particular ArchiCAD and Revit.  Also, some of the general-purpose terrain software on the Commercial Software page have significant building-specific functionality.

• ghostTown plugin for 3DS MAX
  • Seems to have ceased development in 2012, but as late as 2014 the free version ("ghostTown lite") was used in projects including The making of the CASA Urban Roller Coaster
• CityEngine
  • originally a service of Swiss production firm Central Pictures, which evolved from the Siggraph 2001 paper "Procedural Modeling of Cities"
  • the expected workflow fits into the approach of generating scene for e.g. movies:
    1. provide examples or sketches
    2. collaborative design and changes
    3. development of facade renderers
    4. rendering e.g. on client side (using custom shaders)
  • As of 2009: "It has evolved quite a bit, i.e.. some more Siggraph papers have been fed into it.... is now a commercial product of Procedural Inc. a software company based in Zurich, Switzerland."
  • In 2010, they produced a version with special Vue export called CityEngine Vue
  • In 2011, they were acquired by ESRI.
• Procedural City Generation in Python (2015)
  • Generates a semi-random road map based on three patterns of road layout, then populates the "lots" generated with procedural buildings geometry.
  • Open source, with a minimal GUI.
  • The output can be sent to Blender.
    
• SceneCity
  • A popular addon for Blender, free for most uses, which generates somewhat abstract sityscapes of blocky buildings.A popular addon for Blender, free for most uses, which generates somewhat abstract sityscapes of blocky buildings.
  • It varies the colors, materials and procedural elements enough to produce a reasonable approximation of a city at a distance, but realism is not a goal, and it does not operate on real data at all.
  • As of 2015 the basic version is free, pro version is $80.
    
• Tyson Ibele's Building Generator Plus (2009-2011)
  • A (script) plugin for 3DS MAX 9 and above, which generates fully textured, detailed procedural buildings.
  • Quite good at making dormers, adding roof culture, etc.
  • 
• CGSD did some highly visible commercial work in the field
  • Parametric Planets: Automatic Parametric Generation of 3-D Databases
    • currently implemented as a plugin to Terrex's TerraVista, with minimal user interface
    • parameters include building size and height, architecture style (as many as 20) and presence of landscaping
    • doesn't currently expose lower-level parameters such as building color
    • while the license to Terrex is for static scene generation, nothing prevents CGSD from supporting other uses such as dynamic, on-the-fly building generation
  • their observations:
    • it takes about 60 architectural styles to describe nearly all the residential buildings in the USA
    • older buildings are much more uniform in style, hence are easier to parameterize than newer buildings
• Generative Modeling Language
  • a text-based language, similar to PostScript, for procedural description of 3D objects
  • origin is in German academia
  • although the acronym is GML, it has no connection to GML the file format definition language
  • examples include chairs, wheels, and even entire buildings
  • there is a free web plugin for 3D viewing, and a cross-platform IDE
  • it's not clear if the source for the runtime is open or not
  • the author wrote a a massive, impressive thesis (300 pages!) on every aspect of procedural modeling
• GDL (Geometric Description Language)
  • a BASIC-like scripting language, part of ArchiCAD (see CAD Software)
  • usually used to construct small features like windows or furniture, but can be used to generate entire buildings
  • According to the author of the GDL Cookbook:
    • "Graphisoft are due to release GDL as a freely available language, a bit like JAVA from Sun systems. They see GDL as being a kind of Java for the 3D world. they hope that AutoDesk and others will license it as a language for 3D parametric object making."
      GDL is a good way to make certain objects. For example, one can make elements like bridges, traffic furniture etc, (the benefit being that because it is parametric, the same object file can build a variety of 3D results."
  • FastFraming ($395) and TrueGutters ($35) are examples of GDL programs which procedurally generate the structural details of a building

See also: Academic Papers and Projects

Older / Historical

• Gamr7 (2007-2012), France
  • was the maker of Ürban PAD, a "complete procedural toolset for generating detailed, lightweight, on-the-fly urban virtual environments [...] Automatic building and city generation coupled with full manual editability make Ürban PAD the tool of choice for fast creation rich, editable urban content for next generation games."
  • It folded in April 2012. Where did the technology go?
• Stefan Greuter's Research Prototypes (2003)
  • "Undiscovered City" and "Street Pattern Examiner" are demo applications (Windows binaries) based on his PhD research (Undiscovered Worlds – Towards a Framework for Real-Time Procedural World Generation (pdf) 
  • very high level: inputs are essentially street widths; all other properties including all building sizes and appearances are randomized from a seed based on the building's location
  • demo apps are nicely self-contained
    
• Binary Worlds - Descensor Engine
  • a commercial toolkit for Windows which produces and renders large artificial city scenes
  • positioned as a middleware component for games
  • includes a runtime and an editor
  • the generated models reportedly follow urban and architectural common rules
  • apparently gone as of 2015
• Algorithmic City Generator by Edwardo Hidalgo
  • built on the a href="http://aig.cs.man.ac.uk/maverik/">Maverik VR engine (GPL)
  • an undergraduate project at the Advanced Interfaces Group at the University of Manchester
  • two-step process: first the city streets are laid out, then buildings are supplied to fill the map
  • no longer online as of 2007
• City Generator is a "plug-in" for POV- Ray (free raytracer)
  • can generate amazingly complex cities, although they're entirely artificial, i.e. no real-world inputs
  • numerous building types, extensible
  • even does streets, sidewalks, vehicles
  • unfortunately not applicable beyond the POV-Ray community
• Village Terraformer, academic project, Jose Luis Leviaguirre at University of Bristol CS Dept. (2001?)
  • a project to `build´ virtual cities using a rule-based approach i.e. tall buildings near the center of the city, urban areas on the outskirts etc.
• input from Deanan: "In Toy Story, Eben Ostby (Executive Animation Scientist at Pixar) wrote some renderman stuff to generate the houses on the street procedurally."
  • from an interview: 'On "Toy Story" we spent months on the houses. A typical house was something like a month of work to get done.'
  • used an internal process called "Pure mdl (proprietary procedural scripting language)"