Semantic Steering

Fluid simulation tools are capable of predicting natural processes and can be employed for the assistance in the human decision making process. Existing solutions lack a number of important features needed for a feasible support system. Very important is the usability of the simulation tools by non-experts without special fluid simulation expertise. More research is thus needed which fully exploits modern visualization, steering and simulation technologies. Especially, with the capabilities of graphics hardware clusters, everybody will have access to affordable supercomputing power on their desktop. Until now, little work has been done to use this power for knowledge generation via simulation steering. In this proposal we suggest a novel computational steering system that uses visualization in every aspect of the problem solving and provides effective feedback via an intuitive interface. The proposed technique enables users to interact with a remote simulation system based on their understanding and to examine alternative scenarios in a short period of time. Among the application areas of the suggested system we consider the industrial design of components where rapid prototyping is required. Using a less accurate but fast and intuitive system will help to evaluate whether a certain concept is promising during the design phase. Another important application will be the assistance in emergency situations that are caused by natural disasters such as floods, where safety and damage limitation depend on fast decisions. Our vision is that, even under time-critical circumstances, emergency personnel on-site will be able to analyze the imminent situation quickly to finally choose the best response strategy. Consider a flooding situtation, where helpers are trying to prevent damage by arranging flow barriers in different locations. Using a mobile device like a hand-held tablet pc, the helpers are capable to quickly setup and perform a simulation. Interactive 3d renderings and 2d sketches of the local area illustrate the simulation outcome and show the flooding risks. Assuming that later, the weather conditions change unexpectedly, quick responses are necessary. By means of intuitive drawing with a control pen, users rearrange the barriers and start additional simulations. In such an interactive cycle, helpers are able to quickly optimize the arrangement of the barriers. To realize our vision we plan the integration and extension of methods from multivariate visualization and computational steering. This combination evolves into a new concept we call semantic steering: Users will be able to steer simulations based on their knowledge and understanding. We suggest to move from a direct manipulation of numbers towards interaction with advanced visual controls. There is no more need for complicated rethinking, users simply sketch their ideas. Visual analytics will be crucial for the success of the project. Visualization is a natural way to get insight into the complex simulation outcome and to understand the relevance of decisions made. Novel techniques are required as users will be confronted with a whole range of simulation runs. To develop and show the feasibilty of our concepts we will incorporate existing simulation solutions that are implemented on graphics hardware and provide a good tradeoff between accuracy and speed. New methods for scalable visualization, interaction, analytics and data-handling are necessary and we have compiled a team of senior and junior scientists with experience in both scientific research and industrial applications to solve the involved questions.

Computer simulation has become a ubiquitous tool to investigate the nature of systems. When steering simulations, users modify parameters to study their impact on the simulation outcome. The ability to test alternative options provides the basis for computer-aided decision making and can be exploited in areas such as flood management. In this project, a novel software has been developed which enables users to explore alternative flooding scenarios in a virtual environment. To make robust decisions, user can pose "What if" - questions to the system without the need for simulation expertise. Typical queries include: What happens if a mobile flood protection wall breaches? Can we protect important buildings by constructing a series of sandbag barriers? What happens if we place the sandbags somewhere else?Today, much effort is put into faster and more accurate simulation components. At the same time, the simulation methods become more and more complex and a tremendous technical expertise is required from users to be able to exploit them. For this reason, we have developed comprehensible visual interfaces to ease the control of complex simulation systems. The presented visualizations enable users to create and analyze multiple flood simulation runs in an intuitive way. This has been made possible by a novel integration of simulation and visualization within one software tool that is called Visdom. At its core lies a 2D-visualization of scenarios which allows users to quickly navigate and compare them. New decisions are introduced through the concept of branching. During this process, users do not have to alter the underlying simulation parameters directly, instead, they simply sketch their ideas into an intuitive 3D-representation of the situation at hand. For example, a sandbag barrier can be quickly drawn into the rendering of a city, using a mouse input or a mobile tablet device. The drawings are then automatically transferred into parameters of the underlying simulation runs. Multiple representations of simulation results let users compare and understand the impact of their decisions made. This way, important information such as the damage to buildings can be quickly extracted. Moreover, the system allows for the exploration of large variations of choices, allowing the analyst to capture the uncertainty involved and to extract relevant worst-case information for making more robust decisions.The efficient and flexible combination of time-dependent simulation and visualization within one tool was one of the major challenges which we have solved in the course of the project. Our generic solution is independent of the application domain and simulation technology. Traffic management, evacuation planning, industrial prototyping or surgery planning could also benefit from a technique that allows the user to compare design decisions interactively.Further general information about Semantic Steering and Visdom can be found here: http://visdom.at/media/pdf/press/visdom%20-%20integrated%20visualization.pdf