FABRICATION OF PARTIALLY DOUBLE-CURVED SURFACES OUT OF FLAT SHEET MATERIAL THROUGH A 3D PUZZLE APPROACH
Abstract: The topic of this paper is the connection of digital modeling with generative programming and rapid prototyping, to produce physical sketch surface models. The physical surface models are assembled out of developable strips connected through a puzzle-like detail. The use of programming as a design approach allows the generation of connection details that corresponds to the rules of flat sheet rapid prototyping techniques of laser cutting and water jet cutting. With numerically controlled cutting, there is no need to keep the joint detail related to manually achievable forms or to apply a standardized dimension. This paper demonstrates the possibilities of programming to generate cutting geometries that adapt to the local surface properties. The larger perspective of the research approach is the question of how to formulate and capture design intention through programming. What influence does the use of generative modeling in combination with rapid prototyping have on the design language of physical objects?
Keywords: fabrication, generative design
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Rashidi A,Brilakis I,Vela P
Built infrastructure point cloud data cleaning: an overview of gap filling algorithms
Abstract: Video captured from infrastructure scenes can be used to generate point cloud data (PCD) as a potential solution for acquiring spatial information of built infrastructure - however, video based PCD is incomplete and includes gaps, outliers and poor/non-reconstructed areas. This phenomenon has a negative impact on both visualization and measurement practices and is mainly caused by a number of reasons including insufficient coverage of all views while videotaping the scene, lack of sufficient features on uniform surfaces and possible errors in calibration, matching and optimization algorithms. To tackle this issue, researchers suggested various post processing algorithms for reconstructing missing surfaces and filling gaps/holes. This paper provides an overview on these algorithms summarize their properties in terms of efficiency, ability to work in complex geometry settings and running time. As the comparison study, three most common hole filling algorithms: MSL, GG and RFR were implemented and tested on a number of real built infrastructure scenes as the case studies. Number of generated 3D points for filling the gaps, proper distribution of points on covered surfaces and running time are three major comparison metrics has been taken into account. Results indicate that in general PML outperforms other algorithms on both flat and curved surfaces.
Keywords: Built infrastructure,triangulation,gap,Point Cloud Data,surface reconstruction
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