Computing discrete geodesic distance over triangle meshes is one of the fundamental problems in computational geometry and computer graphics. In this problem, an effective window pruning strategy can significantly affect the actual running time. Due to its importance, we conduct an in-depth study of window pruning operations in this paper, and produce an exhaustive list […]
Year: 2017
Energized soft tissue dissection in surgery simulation
With the development of virtual reality technology, surgery simulation has become an effective way to train the operation skills for surgeons. Soft tissue dissection, as one of the most frequently performed operations in surgery, is indispensable to an immersive and high-fidelity surgery simulator. Energized dissection tools are much more commonly used than the traditional sharp […]
Evaluation of coupled finite element/meshfree method for a robust full-scale crash worthiness simulation of railway vehicles
The crashworthiness of a railway vehicle relates to its passive safety performance. Due to mesh distortion and difficulty in controlling the hourglass energy, conventional finite element methods face great challenges in crashworthiness simulation of large-scale complex railway vehicle models. Meshfree methods such as element-free Galerkin method offer an alternative approach to overcome those limitations but […]
A fast propagation scheme for approximate geodesic paths
Geodesic paths on surfaces are indispensable in many research and industrial areas, including architectural and aircraft design, human body animation, robotic path planning, terrain navigation, and reverse engineering. 3D models in these applications are typically large and complex. It is challenging for existing geodesic path algorithms to process large-scale models with millions of vertices. In […]
Fast and Memory-Efficient Voronoi Diagram Construction on Triangle Meshes
Geodesic based Voronoi diagrams play an important role in many applications of computer graphics. Constructing such Voronoi diagrams usually resorts to exact geodesics. However, exact geodesic computation always consumes lots of time and memory, which has become the bottleneck of constructing geodesic based Voronoi diagrams. In this paper, we propose the window-VTP algorithm, which can […]
Blue Noise Sampling using an SPH-based Method
We propose a novel algorithm for blue noise sampling inspired by the Smoothed Particle Hydrodynamics (SPH) method. SPH is a well-known method in fluid simulation — it computes particle distributions to minimize the internal pressure variance. We found that this results in sample points (i.e., particles) with a high quality blue-noise spectrum. Inspired by this, […]
Exploitation of multiplayer interaction and development of virtual puppetry storytelling using gesture control and stereoscopic devices
With the rapid development of human-computer interaction technologies, the new media generation demands novel learning experiences with natural interaction and immersive experience. Considering that digital storytelling is a powerful pedagogical tool for young children, in this paper, we design an immersive storytelling environment that allows multiple players to use naturally interactive hand gestures to manipulate […]
Fast multiple-fluid simulation using Helmholtz free energy
Multiple-fluid interaction is an interesting and common visual phenomenon we often observe. In this paper, we present an energybased Lagrangian method that expands the capability of existing multiple-fluid methods to handle various phenomena, such as extraction, partial dissolution, etc. Based on our user-adjusted Helmholtz free energy functions, the simulated fluid evolves from high-energy states to […]
Simulating collective transport of virtual ants
This paper simulates the behaviour of collective transport where a group of ants transports an object in a cooperative fashion. Different from humans, the task coordination of collective transport, with ants, is not achieved by direct communication between group individuals, but through indirect information transmission via mechanical movements of the object. This paper proposes a […]
Essential techniques for laparoscopic surgery simulation
Laparoscopic surgery is a complex minimum invasive operation that requires long learning curve for the new trainees to have adequate experience to become a qualified surgeon. With the development of virtual reality technology, virtual reality-based surgery simulation is playing an increasingly important role in the surgery training. The simulation of laparoscopic surgery is challenging because […]
A Linear Approach for Depth and Colour Camera Calibration Using Hybrid Parameters
Many recent applications of computer graphics and human computer interaction have adopted both colour cameras and depth cameras as input devices. Therefore, an effective calibration of both types of hardware taking different colour and depth inputs is required. Our approach removes the numerical difficulties of using non-linear optimization in previous methods which explicitly resolve camera […]
A human motion feature based on semi-supervised learning of GMM
Using motion capture to create naturally looking motion sequences for virtual character animation has become a standard procedure in the games and visual effects industry. With the fast growth of motion data, the task of automatically annotating new motions is gaining an importance. In this paper, we present a novel statistic feature to represent each […]
Adaptive multi-view feature selection for human motion retrieval
Human motion retrieval plays an important role in many motion data based applications. In the past, many researchers tended to use a single type of visual feature as data representation. Because different visual feature describes different aspects about motion data, and they have dissimilar discriminative power with respect to one particular class of human motion, […]
Posing 3D Models from Drawing
Inferring the 3D pose of a character from a drawing is a complex and under-constrained problem. Solving it may help automate various parts of an animation production pipeline such as pre-visualisation. In this paper, a novel way of inferring the 3D pose from a monocular 2D sketch is proposed. The proposed method does not make […]
Supervised coordinate descent method with a 3D bilinear model for face alignment and tracking
Face alignment and tracking play important roles in facial performance capture. Existing data-driven methods for monocular videos suffer from large variations of pose and expression. In this paper, we propose an efficient and robust method for this task by introducing a novel supervised coordinate descent method with 3D bilinear representation. Instead of learning the mapping […]
Understanding the impact of multimodal interaction using gaze informed mid-air gesture control in 3D virtual objects manipulation
Multimodal interactions provide users with more natural ways to manipulate virtual 3D objects than using traditional input methods. An emerging approach is gaze modulated pointing, which enables users to perform object selection and manipulation in a virtual space conveniently through the use of a combination of gaze and other interaction techniques (e.g., mid-air gestures). As […]
Blending using ODE swept surfaces with shape control and C1 continuity
Surface blending with tangential continuity is most widely applied in computer aided design, manufacturing systems, and geometric modeling. In this paper, we propose a new blending method to effectively control the shape of blending surfaces, which can also satisfy the blending constraints of tangent continuity exactly. This new blending method is based on the concept […]
Visitor Experience Innovation through Systematic Text Analytics and Augmented Reality
Visitor experience Innovation through Systematic Text Analytics and Augmented Reality. The project is focused on generating new and repeat visitors to cultural heritage sites and to make an impact on regional economies. The tools developed by the project will be made available to other UK and French cultural heritage sites on a cloud-based system where […]
Automatic Cage Construction for Retargeted Muscle Fitting
The animation of realistic characters necessitates the construction of complicated anatomical structures such as muscles, which allow subtle shape variation of the character’s outer surface to be displayed believably. Unfortunately despite numerous efforts, the modelling of muscle structures is still left for an animator who has to painstakingly build up piece by piece, making it […]
Energy-based dissolution simulation
We propose an energy-based method for dissolution simulation. Both the fluid (solvent) and solid (solute) are presented by particles. The dissolution priority of solute particles is based on the kinetic activation energy. The position of solute is determined using rigid body dynamics. We demonstrate plausible dissolving behaviours by using examples.
Image-based Hair Pre-Processing for Art Creation A Case Study of Bas-Relief Modelling
To better capture the shapes as well as the rich dynamics of hair, image based modelling techniques have been developed for reconstructing their 3D geometry and important visual features. Most hair images contain inevitable noises which impair reconstructed hair models. Therefore we propose to pre-process hair images and provide an orientation map of hair strands […]
Realistic skin movement for character animation
Skin movement modeling is a crucial element for realistic animation of both human and creature characters. In this paper, we are primarily concerned with a special skin movement effect, skin sliding. Although physical properties, such as skin elasticity, are usually regarded important in physical simulation, it often leads to an increasing computational load. A complete […]
Motion sensitive anchor identification of least–squares meshes from examples
A least–squares mesh is a surface representation consisting of a small set of anchor points and the differential and topological properties of the surface. In this paper we present a novel method to identify motion sensitive anchor points for least–squares meshes from a set of examples. We present a new method called clustered teleconnection analysis […]
Locomotion Skills for Insects with Sample-based Controller
Natural-looking insect animation is very difficult to simulate. The fast movement and small scale of insects often challenge the standard motion capture techniques. As for the manual key-framing or physics-driven methods, significant amounts of time and efforts are necessary due to the delicate structure of the insect, which prevents practical applications. In this paper, we […]
Advanced ordinary differential equation based head modelling for Chinese marionette art preservation
Puppetry has been a popular art form for many centuries in different cultures, which becomes a valuable and fascinating heritage assert. Traditional Chinese marionette art with over 2000 years history is one of the most representative forms offering a mixture of stage performance of singing, dancing, music, poetry, opera, story narrative and action. Apart from a […]
Hand gesture-based interactive puppetry system to assist storytelling for children
The Author(s)Digital techniques have been used to assist narrative and storytelling, especially in many pedagogical practices. With the rapid development of HCI techniques, saturated with digital media in their daily lives, young children, demands more interactive learning methods and meaningful immersive learning experiences. In this paper, we propose a novel hand gesture-based puppetry storytelling system […]
Dynamic skin deformation using finite difference solutions for character animation
We present a new skin deformation method to create dynamic skin deformations in this paper. The core elements of our approach are a dynamic deformation model, an efficient data-driven finite difference solution, and a curve-based representation of 3D models. We first reconstruct skin deformation models at different poses from the taken photos of a male […]
Efficient semi-supervised multiple feature fusion with out-of-sample extension for 3D model retrieval
Multiple visual features have been proposed and used in 3-dimensional (3D) model retrieval in recent years. Since each visual feature reflects a unique characteristic about the model, they have unequal discriminative power with respect to a specific category of 3D model, and they are complementary to each other in model representation. Thus, it would be […]
3D Body Shapes Estimation from Dressed-Human Silhouettes
Estimation of 3D body shapes from dressed-human photos is an important but challenging problem in virtual fitting. We propose a novel automatic framework to efficiently estimate 3D body shapes under clothes. We construct a database of 3D naked and dressed body pairs, based on which we learn how to predict 3D positions of body landmarks […]
Fast individual facial animation framework based on motion capture data
Based upon motion capture, a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer, a camera was used to record her/his front face as a texture map. The radial basis function (RBF) technique was utilized to deform a generic facial model and the texture was remapped to generate […]
Fast surface modelling using a 6th Order PDE
In this paper, we present a new method to improve the efficiency of physics-based surface modeling which creates and manipulates surfaces through physics-based curve deformations. The proposed physics-based mathematical model of curve deformations consists of a vector-valued fourth order ordinary differential equation and boundary constraints. An efficient finite difference solution for curve modeling (FDSCM) is […]
Efficient sketch-based creation of detailed character models through data-driven mesh deformations
Creation of detailed character models is a very challenging task in animation production. Sketch-based character model creation from a 3D template provides a promising solution. However, how to quickly find correct correspondences between user’s drawn sketches and the 3D template model, how to efficiently deform the 3D template model to exactly match user’s drawn sketches, […]
A semantic feature for human motion retrieval
With the explosive growth of motion capture data, it becomes very imperative in animation production to have an efficient search engine to retrieve motions from large motion repository. However, because of the high dimension of data space and complexity of matching methods, most of the existing approaches cannot return the result in real time. This […]
A framework for digital sunken relief generation based on 3D geometric models
Sunken relief is a special art form of sculpture whereby the depicted shapes are sunk into a given surface. This is traditionally created by laboriously carving materials such as stone. Sunken reliefs often utilize the engraved lines or strokes to strengthen the impressions of a 3D presence and to highlight the features which otherwise are […]
Topology preserved shape deformation
This paper presents a novel framework for image and shape deformation, and applies the presented method to 2D shape deformation and image/video magnifying. Our proposed framework maintains two distinct advantages. The first is to enforce the topology preservation constraints on a given displacement field. This allows us to develop a foldover-free constrained deformation approach. The […]
Shape manipulation using physically based wire deformations
This paper develops an efficient, physically based shape manipulation technique. It defines a 3D model with profile curves, and uses spine curves generated from the profile curves to control the motion and global shape of 3D models. Profile and spine curves are changed into profile and spine wires by specifying proper material and geometric properties […]
Relief stylization from 3D models using featured lines
Digital reliefs mimic the style of their real life counterparts, and hence offer an elegant depiction of a 3D shape. Despite an increasing amount of research on digital relief generation in computer graphics, little has been reported on the generation of abstract sculpture forms using pure engraved lines. In this paper, we present a method […]
A Medical VR Simulator in Laparoscopic Rectum Surgery
In recent times, the development of minimally invasive techniques in clinic, such as laparoscopic and endoscopic surgeries, is remarkable. Compared with traditional open surgery, minimally invasive surgery (MIS) is less in surgical trauma, less post-operative pain and a shorter convalescence for patients. In the last ten years, in particular, laparoscopic colorectal surgery has witnessed a […]
Solid modelling based on sixth order partial differential equations
Although solid modelling based on partial differential equations (PDEs) has many advantages, such existing methods can either only deal with simple cases or incur expensive computational overheads. To overcome these shortcomings, in this paper we present an efficient PDE based approach to creating and manipulating solid models. With trivariate partial differential equations, the idea is […]