Semantic Game Worlds

The visual quality of game worlds increased massively in the last three decades. However, the closer game worlds depict reality, the more noticeable it is for gamers when objects do not behave accordingly. An important problem is that the data of a game world is often scattered across different components of the game engine. What lacks is a common semantic representation that can act as the glue between these components. In this thesis we define semantic game worlds as game worlds that are populated with objects enriched with semantics. They offer game programmers a consistent representation that can be shared by game engine components. Moreover, this representation offers designers a way to moderate conflicts between procedural content generation techniques and it enables them to specify object behavior in a generic manner.Department of Intelligent SystemsElectrical Engineering, Mathematics and Computer Scienc

Smooth, Interactive Rendering Techniques on Large-Scale, Geospatial Data in Flood Visualizations

Visualising large-scale geospatial data is a demanding challenge that finds applications in many fields, including climatology and hydrology. Due to the enormous data size, it is currently not possible to render full datasets interactively without significantly compromising quality (especially not when information changes over time). In this paper, we present new approaches to render and interact with detail-varying Light Detection and Range (LiDAR) point sets. Furthermore, our approach allows the attachment of large-scale geospatial meta information and the modification of point attributes on the fly. The core of our algorithm is a dynamic GPU-based hierarchical tree data structure that is used in conjunction with an out-of-core, Levelof-Detail (LoD)-Point-based Rendering (PBR) algorithm to modify data on the fly. This combination makes it possible to augment the original data with dynamic context information that can be used to highlight features (e.g.,routes, marked areas) or to reshape the entire data set in real-time. We showcase the usefulness of our algorithm in the context of disaster management and illustrate how decision makers can discuss a flood scenario covering a large area (spanning 300 km2) and discuss hazards, as well as related protection measures, interactively. One of our presented reference point sets includes parts of the AHN2 data set (14 TB of LiDAR data in total). Previous rendering algorithms relied on a long offline preprocessing (several hours) to ensure a quick data display. This step made any changes to the data impossible. With our new approach, we can modify point sets without requiring a new preprocessing run.Intelligent SystemsElectrical Engineering, Mathematics and Computer Scienc

Declarative Terrain Modeling for Military Training Games

Military training instructors increasingly often employ computer games to train soldiers in all sorts of skills and tactics. One of the difficulties instructors face when using games as a training tool is the creation of suitable content, including scenarios, entities, and corresponding terrain models. Terrain plays a key role in many military training games, as for example, in our case game Tactical Air Defense. However, current manual terrain editors are both too complex and too time-consuming to be useful for instructors; automatic terrain generation methods show a lot of potential, but still lack user control and intuitive editing capabilities. We present a novel way for instructors to model terrain for their training games: instead of constructing a terrain model using complex modeling tools, instructors can declare the required properties of their terrain using an advanced sketching interface. Our framework integrates terrain generation methods and manages dependencies between terrain features in order to automatically create a complete 3D terrain model that matches the sketch. With our framework, instructors can easily design a large variety of terrain models that meet their training requirements.MediamaticsElectrical Engineering, Mathematics and Computer Scienc

An interactive simulation and visualization tool for flood analysis usable for practitioners

Developing strategies to mitigate or to adapt to the threats of floods is an important topic in the context of climate changes. Many of the world’s cities are endangered due to rising ocean levels and changing precipitation patterns. It is therefore crucial to develop analytical tools that allow us to evaluate the threats of floods and to investigate the influence of mitigation and adaptation measures, such as stronger dikes, adaptive spatial planning, and flood disaster plans. Up until the present, analytical tools have only been accessible to domain experts, as the involved simulation processes are complex and rely on computational and data-intensive models. Outputs of these analytical tools are presented to practitioners (i.e., policy analysts and political decision-makers) on maps or in graphical user interfaces. In practice, this output is only used in limited measure because practitioners often have different information requirements or do not trust the direct outcome. Nonetheless, literature indicates that a closer collaboration between domain experts and practitioners can ensure that the information requirements of practitioners are better aligned with the opportunities and limitations of analytical tools. The objective of our work is to present a step forward in the effort to make analytical tools in flood management accessible for practitioners to support this collaboration between domain experts and practitioners. Our system allows the user to interactively control the simulation process (addition of water sources or influence of rainfall), while a realistic visualization allows the user to mentally map the results onto the real world. We have developed several novel algorithms to present and interact with flood data. We explain the technologies, discuss their necessity alongside test cases, and introduce a user study to analyze the reactions of practitioners to our system. We conclude that, despite the complexity of flood simulation models and the size of the involved data sets, our system is accessible for practitioners of flood management so that they can carry out flood simulations together with domain experts in interactive work sessions. Therefore, this work has the potential to significantly change the decision-making process and may become an important asset in choosing sustainable flood mitigations and adaptation strategies.Comp Graphics & Visualisatio

Semantic Crowds: Reusable Population for Virtual Worlds

Recent advances in crowd simulation techniques have led to realistic agent and group behavior through elaborate behavioral models, complex motion planning algorithms and impressive physics systems. As many crowd simulation solutions typically target only specific types of environment and scenario, a variety of special-purpose methods and systems has emerged that are hard to re-configure and re-use in other contexts. Solving this situation demands a higher-level approach that takes re-use and configuration of crowds as a priority, for adequate application in a broad variety of scenarios, virtual environments and inter- action with the entities present in that environment. In this article we propose semantic crowds, a novel approach that allows one to re-use the same crowds for virtually any environment, and have them use the objects available in it in a meaningful manner, without any modification. To have the agents autonomously interact within any virtual world, we minimize in them the information relative to what objects do and how to use them. Instead, that information is stored in the objects themselves, which the agents can then query, based on what they plausibly want to achieve. To facilitate creating such crowds, we devel- oped an interactive crowd editor that provides high-level editing parameters for defining crowd templates. We illustrate the flexibility of semantic crowds by means of two cases, in which we let the same crowd populate quite differently configured airport terminal environments. These examples also highlight that this modular approach easily combines with your custom implementations of agent behavior model and/or motion planner.Intelligent SystemsElectrical Engineering, Mathematics and Computer Scienc