• Spectral Hybrid Simulation

A novel spectral framework is proposed to simulate a hybrid body with both deformable and rigid regions in real-time. We extend the modal analysis technique to rigid body simulation while using the modal warping method to handle rotational deformation in the deformable subsystem, and thus build up a uniform physically based spectral solution for the hybrid system. Moreover, a new strategy that fortifies the connection constraint between subsystems is employed to replace the traditional position constraint expression which accumulates the approximation errors making the whole system unstable...

• Yin Yang, Guodong Rong, Jianfeng Ren, Luis Torres, Xiaohu Guo, "Spectral Hybrid Simulation of Deformable and Rigid Bodies," Technical Report, UTDCS-19-09, University of Texas at Dallas, 2009. [video]

• Deformable Model Streaming

Streaming deformations on complex 3D objects arising from a user’s manipulations is a challenging task. In this research, we propose a framework for real-time streaming of 3D deformations in collaborative learning applications. Our research contributions through this framework include: (i) use of spectrumbased surface deformation for real-time, distributed computation of the 3D model; (ii) handling different clients display capabilities by enabling the deformations to be applied on multiple resolutions of the same 3D object. Our experiments indicate that transmission of deformation information can be accomplished in a very short time, even for large and complicated 3D models...

• Ziying Tang, Guodong Rong, Xiaohu Guo, Balakrishnan Prabhakaran, "Streaming 3D Shape Deformations in Collaborative Virtual Environment," to appear in Proceedings of IEEE Virtual Reality Conference (VR 2010), Waltham, Massachusetts, March 2010. [video]

• Point-Based Manifold Harmonics

We propose an algorithm to build a set of orthogonal Point-Based Manifold Harmonic Bases (PB-MHB) for spectral analysis over point-sampled manifold surfaces. To ensure that PB-MHB are orthogonal to each other, it is necessary to have symmetric discrete Laplace-Beltrami Operator (LBO) over the surfaces. Existing converging discrete LBO proposed by Belkin et al is not guaranteed to be symmetric. We build a new point-wisely discrete LBO over the point-sampled surface that is guaranteed to be symmetric, and prove its convergence...

• Yang Liu, Balakrishnan Prabhakaran, Xiaohu Guo, "Point-Based Manifold Harmonics," Technical Report, UTDCS-15-09, University of Texas at Dallas, 2009. [paper][video][web]

• Centroidal Voronoi Tessellation on GPU

Centroidal Voronoi tessellation (CVT) is widely used in computational science and engineering. The most commonly used method is Lloyd's method, and recently Liu et al propose the L-BFGS method for computing CVT and show that it is faster than Lloyd's method. These methods run on the CPU and are still too slow for many practical applications. We present new techniques to implement these two methods on the GPU for computing CVT on a 2D plane and on a surface, and demonstrate significant speedup of these GPU-based methods over their CPU counterparts...

• Guodong Rong, Yang Liu, Wenping Wang, Xiaotian Yin, Xianfeng Gu, Xiaohu Guo, "Centroidal Voronoi Tessellation on GPU," submitted to IEEE Transactions on Visualization and Computer Graphics, 2009. [video]

• Spectral Surface Deformation

The geometry and motion of the original irregular meshes can be compactly encoded using the low-frequency spectrum of the manifold surfaces. Using the spectral method, the size of the linear/nonlinear deformation system can be significantly reduced to achieve interactive computational speed for manipulating large triangle meshes...

• Guodong Rong, Yan Cao, Xiaohu Guo, "Spectral Mesh Deformation," in The Visual Computer (CGI2008 Special Issue), Vol. 24, No. 7-9, pp. 787-796, 2008. [paper][video][web]
• Guodong Rong, Yan Cao, Xiaohu Guo, "Spectral Surface Deformation with Dual Mesh," in Proceedings of the 21st International Conference on Computer Animation and Social Agents (CASA2008), pp. 17-24, Seoul, Korea, September 2008. [paper][video][web]

• Spectral Blind Watermarking for Manifold Surfaces

We propose a blind and imperceptible spectral watermarking approach for manifold surfaces represented as triangle meshes. The basic idea is to transform the original mesh into frequency domain using the Fourier-Like Manifold Harmonics Transform. The manifold harmonics basis defined on arbitrary topology surfaces is an intrinsic property of the manifold surfaces, which makes our watermarking scheme immune to uniform affine attack (rotation, scaling, and translation) and robust against noise-addition and mesh simplification attacks...

• Yang Liu, Balakrishnan Prabhakaran, Xiaohu Guo, "A Robust Spectral Approach for Blind Watermarking of Manifold Surfaces," in Proceedings of ACM Multimedia & Security Workshop, pp. 43-52, Oxford, UK, September 2008. [paper]

• Harmonic Volumetric Mapping

Harmonic volumetric mapping for two solid objects establishes a one-to-one smooth correspondence between them. It finds its applications in shape registration and analysis, shape retrieval, information reuse, and material/texture transplant...

• Xin Li, Xiaohu Guo, Hongyu Wang, Ying He, Xianfeng Gu, Hong Qin, "Harmonic Volumetric Mapping for Solid Modeling Applications," in Proceedings of ACM Symposium on Solid and Physical Modeling (SPM 2007), pp. 109 - 120, Beijing, June 2007. [paper]
• Xin Li, Xiaohu Guo, Hongyu Wang, Ying He, Xianfeng Gu, Hong Qin, "Meshless Harmonic Volumetric Mapping using Fundamental Solution Methods," in IEEE Transactions on Automation Science and Engineering, Vol. 6, No. 3, pp. 409-422, 2009. [paper]

• Globally Optimal Quasi-Conformal Surface Mapping

We developed a quasi-conformal surface mapping paradigm which minimizes angle distortion and metric distortion of mappings globally based on the intrinsic geometric structure of surfaces...

• Xin Li, Yunfan Bao, Xiaohu Guo, Miao Jin, Xianfeng Gu, Hong Qin, "Globally Optimal Surface Mapping for Shapes of Arbitrary Topology," in IEEE Transactions on Visualization and Computer Graphics, Vol. 14, No. 4, pp. 805-819, 2008. [paper][video][web]

• Spline-Based Thin-Shell Simulation

We developed a new paradigm which elegantly integrates the thin-shell finite-element simulation with geometric design of arbitrary manifold spline surfaces...

• Kexiang Wang, Ying He, Xiaohu Guo, Xianfeng Gu, Hong Qin, "Spline Thin-Shell Simulation of Manifold Surfaces," in Proceedings of Computer Graphics International (Lecture Notes in Computer Science, Springer, Vol. 4035, pp. 570-577), 2006. [paper]

• Global Parameterization for Meshless Simulation

A new approach for the meshless thin-shell elastic deformation and fracture simulation of point-sampled geometry via explicit, global conformal point-surface parameterization...

• Xiaohu Guo, Xin Li, Yunfan Bao, Xianfeng Gu, Hong Qin, "Meshless Thin-shell Simulation Based on Global Conformal Parameterization," in IEEE Transactions on Visualization and Computer Graphics (TVCG), Vol. 12, No. 3, pp. 375-385, 2006. [paper][video][web]

• Shape and Appearance Repair/Editing System

A new surface content completion framework that can restore both shape and appearance (texture) from scaned, incomplete point set inputs...

• Seyoun Park, Xiaohu Guo, Hayong Shin, Hong Qin, "Shape and Appearance Repair for Incomplete Point Surfaces," in Proceedings of the 10th IEEE International Conference on Computer Vision (ICCV 2005), pp. 1260 - 1267, Beijing, October, 2005. [paper][video][web]
• Seyoun Park, Xiaohu Guo, Hayong Shin, Hong Qin, "Surface Completion for Shape and Appearance," in The Visual Computer, Vol. 22, No. 3, pp. 168 - 180, 2006. [paper][video][web]

• Physically-Based Morphing of Point-Sampled Surfaces

An innovative method for naturally and smoothly morphing two point-sampled surfaces via dynamic, meshless simulation...

• Yunfan Bao, Xiaohu Guo, Hong Qin, "Physically Based Morphing of Point-sampled Surfaces," in the 18th International Conference on Computer Animation and Social Agents (CASA 2005), Hong Kong, October, 2005. One of the best papers invited to the journal of Computer Animation and Virtual Worlds, Vol. 16, No. 3-4, pp. 509 - 518, 2005. [paper][video][slides][web]

• Real-Time Meshless Deformation

A real-time meshless simulation paradigm for point-sampled solid objects using Modal Warping technique...

• Xiaohu Guo, Hong Qin, "Real-time Meshless Deformation," in the 18th International Conference on Computer Animation and Social Agents (CASA 2005), Hong Kong, October, 2005. One of the best papers invited to the journal of Computer Animation and Virtual Worlds, Vol. 16, No. 3-4, pp. 189 - 200, 2005. [paper][video][slides][web]

• Scalar-Function-Driven Editing on Point Set Surfaces

A modeling paradigm and system for local and global editing on point set surfaces lets users easily modify the topology of sculpted point sets...

• Xiaohu Guo, Jing Hua, and Hong Qin, "Point Set Surface Editing Techniques based on Level-Sets," in Computer Graphics International '04, pp. 52 - 59, Crete, Greece, June 2004. [paper][slides][web]
• Xiaohu Guo, Jing Hua, and Hong Qin, "Scalar-Function-Driven Editing on Point Set Surfaces," in IEEE Computer Graphics and Applications, Vol. 24, No. 4, pp. 43 - 52, 2004. [paper][web]

• Haptics-Based Editing on Point Set Surfaces

A modeling paradigm for haptics-based editing on point set surfaces exploits implicit surfaces, physics-based modeling, point-sampled surfaces, and haptic feedback...

• Xiaohu Guo and Hong Qin, "Dynamic Sculpting and Deformation of Point Set Surfaces," in Pacific Graphics' 03, pp. 123 - 130, Canmore, Alberta, Canada, October 2003. [paper][slides][web]
• Xiaohu Guo, Jing Hua, and Hong Qin, "Touch-Based Haptics for Interactive Editing on Point Set Surfaces," in IEEE Computer Graphics and Applications, Vol. 24, No. 6, pp. 31 - 39, 2004. [paper][web]