Dieter Hildebrandt

Service-oriented 3D Geovisualization Systems

3D geovisualization systems (3DGeoVSs) that use 3D geovirtual environments as a conceptual and technical framework are increasingly used for various applications. They facilitate obtaining insight from ubiquitous geodata by exploiting human abilities that other methods cannot provide. 3DGeoVSs are often complex and evolving systems required to be adaptable and to leverage dis­tributed resources. Designing a 3DGeoVS based on service-oriented architectures, standards, and image-based representations (SSI) facilitates resource sharing and the agile and efficient construc­tion and change of interoperable systems. In particular, exploiting image-based representations ([Reps) of 3D views on geodata supports taking full advantage of the potential of such system de­signs by providing an efficient, decoupled, interoperable, and increasingly applied representation. However, there is insufficient knowledge on how to build service-oriented, standards-based 3DGeoVSs that exploit IReps. This insufficiency is substantially due to technology and interoper­ability gaps between the geovisualization domain and further domains that such systems rely on. 

This work presents a coherent framework of contributions that support designing the software architectures of targeted systems and exploiting !Reps for providing, styling, and interacting with geodata. The contributions uniquely integrate existing concepts from multiple domains and novel contributions for identified limitations. The proposed software reference architecture (SRA) for 3DGeoVSs based on SSI facilitates designing concrete software architectures of such systems. The SRA describes the decomposition of 3DGeoVSs into a network of services and integrates the following contributions to facilitate exploiting !Reps effectively and efficiently. The proposed generalized visualization pipeline model generalizes and overcomes expressiveness limitations of the prevalent visualization pipeline model with respect to transforming !Reps. The proposed approach for image-based provisioning enables generating and supplying service consumers with image-based views ([Views).
IViews act as first-class data entities in the communication between services and provide a suitable !Rep and encoding of geodata. The proposed approach for image-based styling separates concerns of styling from image generation and enables styling geodata uniformly represented as !Views specified as algebraic compositions of high-level styling operators. The proposed approach for interactive image-based novel view generation includes an architectural pattern that generalizes common novel view generation and enables generating new !Views from existing !Views in response to interactive manipulations of the viewing camera. The proposed interactive assisting, constrained 3D navigation technique demonstrates how a navigation technique can be built that supports users in navigating multiscale virtual 3D city models, operates in 3DGeoVSs based on SSI as an application of the SRA, can exploit !Reps, and can support collaborating services in exploiting IReps. 

The validity of the contributions is supported by proof-of-concept prototype implementations and applications and effectiveness and efficiency studies including a user study. Results suggest that this work promises to support designing 3DGeoVSs based on SSI that are more effective and efficient and that can exploit !Reps effectively and efficiently. This work presents a template software architecture and key building blocks for building novel IT solutions and applications for geodata, e. g., as components of spatial data infrastructures.