Abstract

Abstract

Abstract
The municipal planning and management tasks are generally performed based on text documents or through digital maps provided by geographic information systems (GIS). However, most municipal GIS follow different data models, leading to interoperability problems when there is a need to combine data from different sources. Furthermore, most of the time these tasks are performed in a collaborative way between the municipal technicians, emerging some difficulties in decision making due to the three-dimensional nature of urban space. Thus, this paper describes a methodology which can integrate multiple sources of real data from diverse municipal GIS, in a unified data model based on the CityGML specification. This model is mapped onto an urban ontology oriented for procedural modeling, which, in turn, produces the threedimensional models of the urban environments. The system developed operates in a client-server approach, where the server is responsible for mapping the urban information to the unified data model and the client represents the procedural modeling technology that generates the urban environment in three-dimensional format, allowing users to interact and amplify the existing urban information.

Abstract
This paper presents Geospatial L-systems, a new extension of L-systems that incorporates geospatial awareness, and shows an application of this new tool in the expeditious modelling of urban environments, integrated with a modelling system with interoperable access to data sources. L-systems have been used in Computer Graphics for the modelling of plants, and in a few experiments to model urban environments. However, the lack of geospatial awareness is a limitation and in spite of some developments like open l-systems introduced the ability to communicate with the environment, there was a need for more flexibility. A new modelling system, named XL3D, generates virtual urban environments automatically from a XL3D document with a modelling specification. This modelling system accesses data sources in a interoperable way and the modelling processes are based on L-systems. The integration of geospatial L-systems with the XL3D modelling system has increased its potential for automation and improved the potential to generate virtual urban environments with a higher level of detail and visual fidelity, with a lower level of complexity of the modelling processes. These facts are shown in a case study where a virtual urban environment taken from an area in the Porto downtown is generated by this solution. © The Eurographics Association 2006.

Abstract
Finding an effective control interface to manipulate complex geometric objects has traditionally relied on experienced users to place the animation controls. This process, whether for key framed or for motion captured animation, takes a lot of time and effort. We introduce a novel sketching interface control system inspired in the way artists draw, in which a stroke defines the shape of an object and reflects the user's intention. We also introduce the canvas, a 2D drawing region where the users can make their strokes, which determines the domain of interaction with the object. We show that the combination of strokes and canvases provides a new way to manipulate the shape of an implicit volume in space. And most importantly, it is independent from the 3D model rig. The strokes can be easily stored and reused in other characters, allowing retargeting of poses. Our interactive approach is illustrated using facial models of different styles. As a result, we allow rapid manipulation of 3D faces on the fly in a very intuitive and interactive way. Our informal study showed that first time users typically master the system within seconds, creating appealing 3D poses and animations in just a few minutes. © 2011 ACM.

Abstract