3D urban models

This paper describes the application of procedural modeling methods to automati-cally derive 3D models of high visual quality for a highly detailed and quick visu-alization of complex city models. We discuss the applicability of a proceduralmodeling pipeline of shape grammars in urban planning to derive meaningful 3Dcity models. Therefore we analyze CGA shape, a novel shape grammar for theprocedural modeling of CG architecture, for its usage in architectural planningprocesses. Our system gives rise to three exciting applications in the field of citymodeling and city visualization enabling a quick decision making and iterativedesign workflow: modeling of master plans, evaluation of built environments andplanning of urban open spaces. It is capable to produce building shells with highvisual quality and geometric detail. Context sensitive shape rules allow the user tospecify interactions between the entities of the hierarchical shape descriptions.Selected examples demonstrate solutions to previously noted challenges.

In this paper, the suitability and usability of VRML for urban modelling is discussed based on the experience gained by the creation of urban models of varying sizes, level of detail and use. Areas where the current VRML specification is failing to satisfy the needs of large-scale urban modelling are highlighted. Properties of a successful alternative or VRML3.0 specification are suggested and briefly discussed.

Multimediality is composed of “audiovisual richness, cognitive and instructive depth, interactivity”[i] and a multimedia product should be “intense, profound and versatile, riveting like a film, methodical like a book and interactive like a videogame”[ii]. With these definitions as a starting point, the proposed paper aims at investigating the possibility of increasing the awareness of our cultural heritage and spreading that knowledge using the latest technological innovations. Particular attention is given to the “3D digital scene” with reference to architectural and urban cultural heritage, as it is an excellent means of giving access to the cultural content as well as being a hub for collecting information. This approach, founded on sensorial and emotional involvement, is in effect of added value for communication, and for the elaboration and development of information and content. This makes it an extremely valid tool for the enhancement of our cultural heritage.

This paper presents a semi-automatic visualization method for the evaluation of urban environments that is based on artificial intelligence. It proposes the use of agent-based crowd simulation software on a mid-scale urban planning level for design evaluation. The information on agents’ movements
is noted in standard raster images. The results are maps that are easy to understand. These maps show movement paths of the agents and density and give further conclusion on bottlenecks in planning contexts. Key measures, like the occupant movement in a given district, until now relied greatly on empirical knowledge or data that could be only gathered after an urban design had become built reality. Our method focuses on the adaptation of common software technology that is originally situated in film and TV productions. A practical workflow shows how our method can be easily integrated in daily design tasks.

Identifying the right roofs to install solar panels inside a urban area is crucial for both private citizens and the whole local population. The aim is not easy because a lot of consideration must be made: insolation, orientation of the surface, size of the surface, shading due to topography, shading due to taller buildings next the surface, shading due to taller vegetation and other possible problems typical of urban areas like the presence of chimneys. Accuracy of data related to the analyzed surfaces is indeed fundamental, and also the detail of geometric models used to represent buildings and their roofs. The complexity that these roofs can reach is elevated. This work uses LiDAR data to obtain, with a semi-automatic technique, the full geometry of each roof part complementing the pre-existing building data in the municipal cartography. With this data is possible to evaluate the placement of solar panels on roofs of a whole city analyzing the solar potential of each building in detail. Other traditional techniques, like photogrammetry, need strong manual editing effort in order to identify slopes and insert vector on surfaces at the right height. Regarding LiDAR data, in order to perform accurate modelling, it is necessary to obtain an high density point cloud. The method proposed can also be used as a fast and linear workflow process for an area where LiDAR data are available and a municipal cartography already exist: LiDAR data can be furthermore successfully used to cross-check errors in pre-existent digital cartography that can remain otherwise hidden.

In this paper we discuss how the planning of complex urban systems can be supported by combining (a) dynamic, complimentary visualization software toolkits for planning, project management and visualizing neighborhoods, (b) interactive real-built information architecture, (c) multi-touch, large format display devices and (d) collaboration techniques into a tool for modeling and designing future cities called Value Lab. Finally, we show comprehensive examples from research, application, and teaching.

ABSTRACT: We present a method for populating procedurally generated 3D city models with crowds of artificial agents. It is targeted towards the analysis, prediction and visualization of occupant behaviour in urban planning. We simulate and quantify correlations on the following aspects: functions of buildings, number of people and fluctuation in density. Potential practical applications are for example a) to determine bottlenecks in public transit, b) to identify possible problems for evacuation scenarios, c) to evaluate the demand for and the accessibility of amenities as well as d) the stress of pedestrians to evaluate quality of life indicator for a given urban region . The occupants’ location data – represented by the agents - and relevant semantic metadata are encoded inside a grammar-based city modelling system. This information is used for the context-dependent automatic placement of occupant locators during the procedural generation process of the urban 3D model. Most of the underlying parameters are interconnected with each other. For example, the number of resulting agents corresponds to the size, function and location of one specific building. Once a 3D city model has been generated, occupants are represented by agents using a) a commercial fuzzy logic system and b) pre-animated 3D avatars. The agents find their way through the city by moving towards points of interest to which they are attracted. Each individual agent draws specific paths while interacting with the urban environments and other agents. Every path describes a set of parameters, for example speed, space available and level of exhaustion. The ensuing visual diagrammatic representation shows the resulting agent paths in correlation with the virtual environment. This offers the opportunity to investigate parts of a city and optimise corresponding aspects with minimal interventions on the urban level. We show the application of this method to evaluate planning interventions in the urban fabric and monitor the correlating effects.

This paper presents a novel approach for the automatic creation of vegetation scenarios in real or virtual 3D cities in order to simplify the complex design process and time consuming modeling tasks in urban landscape planning. We introduce shape grammars as a practical tool for the rule-based generation
of urban open spaces. The automatically generated designs can be used for pre-visualization, master planning, guided design variation and digital content creation in general (e.g. for the entertainment industry). In a first step, we extend the CGA shape grammar by Müller et al. (2006) with urban planning operations. In a second step, we employ the possibilities of shape grammars to encode design patterns (Alexander et al., 1977). Therefore, we propose several examples of design patterns allowing for an intuitive high-level placement of objects common in urban open spaces (e.g. plants). Furthermore, arbitrary interactions between distinct instances of the vegetation and the urban environment can
be encoded. With the resulting system, the designer can efficiently vegetate landscape and city parks, alleys, gardens, patios and even single buildings by applying the corresponding shape grammar rules. Our results demonstrate the procedural design process on two practical example scenarios, each one covering a different scale and different contexts of planning. The first example illustrates a derivation of the Garden of Versailles and the second example describes the usage of high-level rule sets to generate a suburbia model.

Visualization of huge data sets for activities in business worlds, entertainment industries and extended visualization in sciences are one of the most exciting chances in architecture. They can result in interweaving physical spaces - physical architectures - with electronic data spaces - virtual architectures. Places and localities with distances in geographical, intercultural and economic matters do not need to exist separated any longer. The networking concepts shout for the use of new architectural languages. Architectural interfaces in physical and digital spaces deliver associated communication, collaboration and learning - breaking up distances in time and geographic spaces. Inside this paper we will discuss how information architecture could be set up in existing buildings with the Value Lab as an example and which methods can be used to develop and to design physical architecture. We present the Value Lab as a recent prototype for Information Architecture

Successful sustainable urban planning has to deal with existing demands in urban design connected to a highly complex system in every direction of business a planner could think of. Furthermore, reality frequently overtakes ongoing planning. These circumstances are especially severe for the urban planning of mega cities, where sustainability must be in the focus of interest for several reasons. “Green lungs”, as one example supporting sustainability within urban environments enhance the functionality of cities to balance humidity locally, to shade buildings and sites and to enable public recreation as well as to reduce air pollution directly and indirectly. This quantitatively and qualitatively less explored branch of urban design requires complex and time consuming modeling tasks even on a master planning scope. In this paper we describe a novel method to create sustainable urban vegetation designs automatically as a kind of early simulation step, which can be used as a guideline for following master planning tasks of high-density urban environments. We had formalized sustainability criteria available in current planning knowledge into CGA shape grammar, which had been introduced by [1]. Additionally, we extended these urban planning rule sets with defined urban landscape patterns. We use these patterns with a procedurally model rule-based distribution and placement of vegetation as well as landscape objects to generate sustainable urban environments. We also show how to use a shape grammar in combination with procedural methods that iteratively develop an urban design, automatically creating more and more details in order to plan sustainable cities more effectively. We link the use of patterns [2] and the design possibilities of shape grammars to plan sustainable design. As results, we present the simulated master plans of different sustainable urban environments in different climates. This paper evolves out of a recent paper [3] of the authors with a strong similarity in section 1-5. Exception: The contributed work is extended by the use of design grammars suited for sustainable design. The extensions adhere especially to the application of design patterns in the context of sustainable master planning and are focused but not limited to vegetation scenarios.

Today’s design processes involve many participants and demand new methods of communication for designers, developers and users. Using Virtual Reality (VR) as a design tool has become increasingly common. Regarding visual expression, photorealism is often strived for, even though this might not always be in accordance with the main purpose of the visualization-project. The research behind this paper regards the development of VR as an architectural design tool that can be used throughout the entire design process, from sketch to final presentation. Here we present results from a comparison between different sketching styles and photorealism in the texturing of an urban planning model. The aim is to show how sketch-like expressions in the texturing of a model can clarify and simplify the understanding of a building project (area plan, housing area, road design). The target group is located within municipalities (architects, planners) and the consultant industry (road designers/engineers, landscape architects). Data was collected from questionnaires answered by 20 participants, all of them professional users of VR. They assessed the experience of the texturing styles in the test model on desktop-PCs. The results revealed important differences and similarities in the perception of the sketching styles vs. the photorealistic style. The evaluation revealed a desire for more sketch-like expressions supporting conceptual design thinking. Even so, models should provide a high level of detail and good spatial experience. Aesthetic factors are considered important. The results contribute to a better understanding of technical and aesthetic limitations of photo-realism in VR.

This paper describes how the Value Lab is a) developed and b) used in education, research and workshops for (1) Interactive urban design and scenario planning that includes methods to support concurrent collaborative urban design over distances, and scenario planning based on defined case studies; (2) Visualization techniques for the detection and prediction of changes in urban environments; (3) Knowledge transfer to synthesize, interact with and communicate essential knowledge and findings from an array of disciplines for decision making, education, training, demonstration, and public discussions.

In this paper, we address the problem of effective visualization of and interaction with multiple and multi-dimensional data supporting communication between project stakeholders in an information cave. Moreexactly, our goal is to enable multiple users to interact with multiple screens from any location in an informationcave. We present here our latest advancements in developing a novel human-computer interaction system that is specifically targeted towards room setups with physically spread sets of screens. Our system consists of a set of video cameras overseeing the room, and of which the signals are processed in real-time to detect and track the participants, their poses and hand-gestures. The system is fed with camera based gesture recognition. Earlyexperiments have been conducted in the Value Lab (see figure 1), that has been recently introduced at ETH Zurich,and they focus on enabling the interaction with large urban 3D models being developed for the design and simulation of future cities. For the moment, experiments consider only the interaction of a single user with multiplelayers (points of view) of a large city model displayed on multiple screens. The results demonstrate the huge potential of the system, and the principle of vision based interaction for such environments. The work continues onthe extension of the system to a multi-user level.

This paper presents a geometric approach for modelling tree roots with different Levels of Detail, suitable for analysis of the tree anchoring, potentially occupied underground space, interaction with urban elements and damage produced and taken in the built-in environment. Three types of tree roots are considered to cover several species: tap root, heart shaped root and lateral roots. Shrubs and smaller plants are not considered, however, a similar approach can be considered if the information is available for individual species. The geometrical approach considers the difficulties of modelling the actual roots, which are dynamic and almost opaque to direct observation, proposing generalized versions. For each type of root, different geometric models are considered to capture the overall shape of the root, a simplified block model, and a planar or surface projected version. Lower detail versions are considered as compatibility version for 2D systems while higher detail models are suitable for 3D analysis and visualization. The proposed levels of detail are matched with CityGML Levels of Detail, enabling both analysis and aesthetic views for urban modelling.

How can architects and urban planners design sustainable future cities?Are urban designers really designing urban systems? And which new computer-based techniques have changed the way they think, plan, and communicate? In thisarticle we will investigate how design thinking can contribute to the planning of sustainable future cities. We will emphasize the benefits of using computer-basedtechniques for purposes such as analysis, simulation, and visualization of complexurban systems. We will introduce a theoretical framework (Future City SimulationPlatform), a new hardware infrastructure (ETH Value Lab) for collaborative design,and novel software-based approaches for typical design tasks, such as the simulationand visualization of scenarios or the collaborative decision-making processes amongstakeholders with different backgrounds.

Wind is the carrier of pollutants and any other gaseous or particle matters in the atmosphere. Stable atmosphere with low wind provides favourable conditions for high contamination of pollutants in urban areas. The importance of mesoscale atmospheric flows in air pollution dispersion has been recognized in the past three decades and has been the focus of intensive research; both observational and numerical. Mesoscale or local scale circulations are more prominent when the synoptic pressure gradients are weak, allowing horizontal temperature contrasts to develop, which in turn lead to mesoscale pressure perturbations. Tehran, a city which is situated at the southern foothills of the Alborz Mountain chain has an average elevation of 1500m, and covers an area of 864 km2. Alborz Mountains have a significant influence on the dynamics and thermodynamic modification of wind regime over the city. At the same time, the Urban Heat Island effect (UHI) can cause its own mesoscale flow, complicating an already complex local scale flow. The topography and the urban fabric can cause slope flows, mountain flows, and valley flows amongst many other factors. Th is paper focuses on the use of state-of-the-art atmospheric numerical model – The Weather Research and Forecasting (WRF) – in an ideal situation to study the characteristics of the mesoscale flow systems that prevail over Tehran when air quality is unfavourable...

Durante los últimos años el Institut Català d'Arquelogia Clàssica, el Museu d'Història de Tarragona, contando con la colaboración de la Generalitat de Catalunya, han desarrollado el proyecto Planimetría Arqueológica de Tárraco, destinado a la elaboración de una planta arqueológica global en la cual se recogieran intervenciones y noticias referentes a los hallazgos arqueológicos existentes. Este trabajo fue publicado utilizando como plataforma de trabajo un SIG construido para tal fin .

Abstract. Nowadays, a large set of involved planning parties are heavily demanded with the definition of holistic in kind requirement specifications for urban planning sites – so called future cities. However, the resulting amount
of specifications for a specific building project poses a great challenge to designers and planners especially when it comes to include this information into their design proposals for a sustainable urban development. These
design performance criteria are traditionally expressed in textual and numerical planning guidelines and which are making it difficult to establish a comprehensive and holistic view onto the domain itself. Therefore we present in this paper a design guide visualization method to overcome this situation for the evaluation of design specification and urban layouts in a qualitative and quantitative manner.

Successful sustainable urban planning has to deal with existing demands in urban design connected to a highly complex system in every direction of business a planner could think of. Furthermore, reality frequently overtakes ongoing planning. These circumstances are especially severe for the urban planning of mega cities, where sustainability must be in the focus of interest for several reasons. “Green lungs”, as one example supporting sustainability within urban environments enhance the functionality of cities to balance humidity locally, to shade buildings and sites and to enable public recreation as well as to reduce air pollution directly and indirectly. This quantitatively and qualitatively less explored branch of urban design requires complex and time consuming modeling tasks even on a master planning scope. In this paper we describe a novel method to create sustainable urban vegetation designs automatically as a kind of early simulation step, which can be used as a guideline for following master planning tasks of high-density urban environments. We had formalized sustainability criteria available in current planning knowledge into CGA shape grammar, which had been introduced by [1]. Additionally, we extended these urban planning rule sets with defined urban landscape patterns. We use these patterns with a procedurally model rule-based distribution and placement of vegetation as well as landscape objects to generate sustainable urban environments. We also show how to use a shape grammar in combination with procedural methods that iteratively develop an urban design, automatically creating more and more details in order to plan sustainable cities more effectively. We link the use of patterns [2] and the design possibilities of shape grammars to plan sustainable design. As results, we present the simulated master plans of different sustainable urban environments in different climates. This paper evolves out of a recent paper [3] of the authors with a strong similarity in section 1-5. Exception: The contributed work is extended by the use of design grammars suited for sustainable design. The extensions adhere especially to the application of design patterns in the context of sustainable master planning and are focused but not limited to vegetation scenarios.