Augmented Reality Technology In Hydraulic And Civil Engineering

Since hydraulic and civil engineering affect environments greatly, it is necessary to develop a new powerful visualization-tool that assesses environmental impact accurately from the esthetics and ecology points of view before engineering is constructed. Clearly, this is of great importance for avoidance of negative effects on environment. Image-based Augmented Reality (AR) can realize these objectives. AR is a technology by which a user's view of the real world is augmented with additional information from a computer model, and thus more information spaces are showed. Visual Impact Assessment (VIA) as a part of environmental impact assessment is a hotspot of research and application at present. AR is one of advanced research projects in the computer research field and one of important visualization-tools. It presents not only more objective plans as well as guidance and information platform in the process of engineering construction, but also a decision support system accurately and timely. As a result, AR raises efficiency greatly, and produces more economic benefit. This dissertation greatly contributes to the field of hydraulic and civil engineering a family of visualization-tools useful for obtaining better VIA. Included among these are:Augmented reality technology in hydraulic and civil engineering is presented for the first time and realized by VC++ tool. The method based on calibration-free augmented reality with affine framework is formulated in detail, and possible questions in the process of algorithm realization such as location and rendering of virtual objects and occlusion problem are analyzed in depth.Further, methods of resolution are given. The typical visualization examples forearth-rock dam, gravity dam and bridge are shown. Moreover, the process oflandslide is simulated successfully by AR, and the result is realistic. Comparedwith traditional visualization tools such as design drawings, scale models andgraphics-based virtual reality, its assessment is more objective.A new application framework based on perspective for calibration-free AR isformulated for the first time, and so this method has enriched the AR tools.Further, the visualization results for hydraulic and civil engineering areimproved.A new approach for resolving occlusion problem in augmented reality ispresented. The heart of this algorithm is to track at least four fiducial pointsfrom frame to frame that construct the affine frame, and thus the occlusioncontours between virtual and real objects can be reconstructed and reprojected.Further, each contour is labeled as being "behind" or "in front of in the firsttwo frames, depending on whether it is in front of or behind the virtual object,so the occlusion is solved.A new approach for determining the centers of color fiducial cluster ispresented.The extensive application examples show that this method with calibration-freeAR has a broad prospect in the field of visual impact assessment of hydraulic and civil engineering.