Browsing by Author "Hou, Fei"

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    Inverse Modelling of Incompressible Gas Flow in Subspace
    (© 2017 The Eurographics Association and John Wiley & Sons Ltd., 2017) Zhai, Xiao; Hou, Fei; Qin, Hong; Hao, Aimin; Chen, Min and Zhang, Hao (Richard)
    This paper advocates a novel method for modelling physically realistic flow from captured incompressible gas sequence via modal analysis in frequency‐constrained subspace. Our analytical tool is uniquely founded upon empirical mode decomposition (EMD) and modal reduction for fluids, which are seamlessly integrated towards a powerful, style‐controllable flow modelling approach. We first extend EMD, which is capable of processing 1D time series but has shown inadequacies for 3D graphics earlier, to fit gas flows in 3D. Next, frequency components from EMD are adopted as candidate vectors for bases of modal reduction. The prerequisite parameters of the Navier–Stokes equations are then optimized to inversely model the physically realistic flow in the frequency‐constrained subspace. The estimated parameters can be utilized for re‐simulation, or be altered toward fluid editing. Our novel inverse‐modelling technique produces real‐time gas sequences after precomputation, and is convenient to couple with other methods for visual enhancement and/or special visual effects. We integrate our new modelling tool with a state‐of‐the‐art fluid capturing approach, forming a complete pipeline from real‐world fluid to flow re‐simulation and editing for various graphics applications.This paper advocates a novel method for modelling physically realistic flow from captured incompressible gas sequence via modal analysis in frequency‐constrained subspace. Our analytical tool is uniquely founded upon empirical mode decomposition (EMD) and modal reduction for fluids, which are seamlessly integrated towards a powerful, style‐controllable flow modelling approach.
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    RegionSketch: Interactive and Rapid Creation of 3D Models with Rich Details
    (The Eurographics Association, 2019) Liu, Shuai; Hou, Fei; Hao, Aimin; Qin, Hong; Lee, Jehee and Theobalt, Christian and Wetzstein, Gordon
    In this paper, we articulate a new approach to interactive generation of 3D models with rich details by way of sketching sparse 2D strokes. Our novel method is a natural extension of Poisson vector graphics (PVG). We design new algorithms that distinguish themselves from other existing sketch-based design systems with three unique features: (1) A novel sketch metaphor to create freeform surface based on Poisson's equation, which is simple, intuitive, and free of ambiguity; (2) Convenient and flexible user interface that affords the user to add rich details to the surface with simple sketch input; and (3) Rapid model creation with sparse strokes, which enables novice users to enjoy the utilities of our system to create expected 3D models. We validate the proposed method through a large repository of interactively sketched examples. Our experiments and produced results confirm that our new method is a simple yet efficient design tool for modeling free-form shapes with simple and intuitive 2D sketches input.
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    Topology Preserving Simplification of Medial Axes in 3D Models
    (The Eurographics Association and John Wiley & Sons Ltd., 2019) Chu, Yiyao; Hou, Fei; Wang, Wencheng; Li, Lei; Lee, Jehee and Theobalt, Christian and Wetzstein, Gordon
    We propose an efficient method for topology-preserving simplification of medial axes of 3D models. Existing methods either cannot preserve the topology during medial axes simplification or have the problem of being geometrically inaccurate or computationally expensive. To tackle these issues, we restrict our topology-checking to the areas around the topological holes to avoid unnecessary checks in other areas. Our algorithm can keep high precision even when the medial axis is simplified to be in very few vertices. Furthermore, we parallelize the medial axes simplification procedure to enhance the performance significantly. Experimental results show that our method can preserve the topology with highly efficient performance, much superior to the existing methods in terms of topology preservation, accuracy and performance.