Urban design and procedural modeling

2006

Cities are important elements of content in digital productions, but their complexity and size make them very challenging to model. Few tools exist that can help artists with this work, even as rapid improvements in graphics hardware create demand for richer content without matching increases in production cost. We propose a method for procedurally generating realistic patterns of land use in cities, automating placement of buildings and roads for artists.

Cities are popular settings for computer game levels and flight simulators. The creation of a virtual city model poses a distinct set of challenges to the designers. The design of a virtual city often starts with the creation of a road network. The road network subdivides the virtual space into smaller areas that are surrounded by streets. These areas can be further subdivided to create areas for buildings, parklands etc. We present a procedural approach to generate urban street networks for virtual cities in real-time on desktop computers with graphic accelerators. A street grid layout for the viewing area is generated based on local information and a small set of parameters. As users travel through the world the street grid is incrementally extended as needed. From the street grid, road geometry and lot shapes can be generated. The lot shapes can be used in a subsequent step to generate the content of the lot such as buildings. This approach facilitates the generation of extremely large cities consisting of lot shapes varying in size and shape.

2009

ABSTRACT: This paper presents the architecture of the City Modelling Procedural Engine (CMPE), a system for the automatic/semi-automatic reconstruction of virtual models of cities. Although the entire data flow can automatically proceed from the beginning to the end, in each stage the manual intervention of the user is possible to correct mistakes caused by the automatic process, to optimize the results, or to introduce further details. The CPME is integrated in XVR, a framework for the development of VR applications.

Urban Planning

Modelling a 3D city poses an interesting challenge. To create a virtual city, a road pattern has to be designed and a large number of buildings need to be generated. Every urban place has a road network, often a superimposed pattern plan that serves a population density and buildings which follow statutory rules. This patterned behaviour of the city is why it is possible to develop rules or “computational instructions,” to generate city models. In this article, we are going to discuss how to use procedural modelling and CityEngine, a rule-based application commonly used in the movie industry and gaming to produce vast realistic cityscapes, for regional and urban planning via an urban analytics approach. Unlike cinema’s imaginary worlds, cities have real-life population dependencies that need to be modelled for the development of planning scenarios. The goal is then to use the generative properties of the procedural modelling approach, along with population prediction models, to crea...

ACM Transactions on Graphics, 2012

We propose a framework that enables adding intuitive high level control to an existing urban procedural model. In particular, we provide a mechanism to interactively edit urban models, a task which is important to stakeholders in gaming, urban planning, mapping, and navigation services. Procedural modeling allows a quick creation of large complex 3D models, but controlling the output is a well-known open problem. Thus, while forward procedural modeling has thrived, in this paper we add to the arsenal an inverse modeling tool. Users, unaware of the rules of the underlying urban procedural model, can alternatively specify arbitrary target indicators to control the modeling process. The system itself will discover how to alter the parameters of the urban procedural model so as to produce the desired 3D output. We label this process inverse design.

The common trend in the scientific inquiry of urban areas and their populations is to use real-world geographic and population data to understand, explain, and predict urban phenomena. We argue that this trend limits our understanding of urban areas as dealing with arbitrarily collected geographic data requires technical expertise to process; moreover, population data is often aggregated, sparsified, or anonymized for privacy reasons. We believe synthetic urban areas generated via procedural city generation, which is a technique mostly used in the gaming area, could help improve the state-of-the-art in many disciplines which study urban areas. In this paper, we describe a selection of research areas that could benefit from such synthetic urban data and show that the current research in procedurally generated cities needs to address specific issues (e.g., plausibility) to sufficiently capture real-world cities and thus take such data beyond gaming.

Computer Graphics Forum, 2011

In this paper, we present new solutions for the interactive modeling of city layouts that combine the power of procedural modeling with the flexibility of manual modeling. Procedural modeling enables us to quickly generate large city layouts, while manual modeling allows us to hand-craft every aspect of a city. We introduce transformation and merging operators for both topology preserving and topology changing transformations based on graph cuts. In combination with a layering system, this allows intuitive manipulation of urban layouts using operations such as drag and drop, translation, rotation etc. In contrast to previous work, these operations always generate valid, i.e., intersection-free layouts. Furthermore, we introduce anchored assignments to make sure that modifications are persistent even if the whole urban layout is regenerated.

Journal For Virtual Worlds Research

The creation of virtual environments, corresponding to real world settings, constitutes one of the most important, but also most time and resource demanding processes in content development for virtual worlds. By querying real-world data sources, the building process can be automated, reducing the need for human intervention. However, these may present additional management difficulties due to their number, dimension, format or level of detail, therefore requiring specific techniques to operate on them. This paper describes the application of a procedural modeling solution, called PG3D System, on the creation of realistic virtual urban environments and their employ in virtual world applications. This system's implementation in spatial database management systems induces fast data access, large data manipulation features, complex query capabilities and format flexibility, allowing the fast creation of large scale virtual environments, imbued with optimized data structures, compat...

Iran University of Science & Technology, 2019

This paper examines procedural modeling as a tool for 3D modeling creation. Procedural modeling historically has been used for 3D visualization of natural features, but with the release of the software CityEngine in 2008, the technology can easily be adopted also in problem domains dealing with urban environments.Then, we will examine and compare two types of modeling, traditional and procedural modeling and consider the advantages of procedural modeling. furthermore, reviewed the features of CityEngine software and introduced CityEngine as a software application that uses the procedural modeling system.Procedural modeling deals with (semi-)automatic content generation by means of a program or procedure. We survey procedural methods that are useful to design roads, buildings, and entire cities. In this survey, we focus particularly on the degree of the use of procedural modeling in the design of cities, streets, buildings, etc, in by CityEngine software. This paper examines how arch...