Automatic pose-independent 3D garment fitting

Given a virtual garment model on a reference human model, we propose an automated 3D garment fitting system that fits the garment model to a target human model. The proposed method can transfer garment models between human models without any user guidance even when the reference and target human models have different poses. Our goal is not to resize or deform the original garment model according to the target human model but to yield realistic fitting results of the given garment on the target human models. Using pose-independent segmentation and cloth simulation, we achieve realistic and automatic fitting results in reasonable running time. Our method can replace the time-consuming manual fitting process that is necessary for many applications that use virtual garments, such as games, animations, CAD tools and online clothing stores.     

From early virtual garment simulation to interactive fashion design

Virtual garment design and simulation involves a combination of a large range of techniques, involving mechanical simulation, collision detection, and user interface techniques for creating garments. Here, we perform an extensive review of the evolution of these techniques made in the last decade to bring virtual garments to the reach of computer applications not only aimed at graphics, but also at CAD techniques for the garment industry.As a result of the advances in the developments of virtual garment simulation technologies, we then detail a framework which fits the needs of the garment industry of virtual garment design and prototyping, concentrating on interactive design, simulation and visualization features. The framework integrates innovative tools aimed towards efficiency and quality in the process of garment design and prototyping, taking advantage of state-of-the-art algorithms from the field of mechanical simulation, animation and rendering.     

Interactive virtual try-on clothing design systems

Clothing computer design systems include three integrated parts: garment pattern design in 2D/3D, virtual try-on and realistic clothing simulation. Some important results have been obtained in pattern design and clothing simulation since the 1980s. However, in the area of virtual try-on, only limited methods have been proposed which are applicable to some defined garment styles or under restrictive sewing assumptions. This paper presents a series of new techniques from virtually sewing up complex garment patterns on human models to visualizing design effects through physical-based real-time simulation. We first employ an hierarchy of ellipsoids to approximate human models in which the bounding ellipsoids are optimized recursively. We also present a new scheme for including contact friction and resolving collisions. Four types of user interactive operation are introduced to manipulate cloth patterns for pre-positioning, virtual sewing and later obtaining cloth simulation. In the cloth simulation, we propose a simplified cloth dynamic model and an integration scheme to realize a high quality real-time cloth simulation. We demonstrate the robustness of our proposed systems by complex garment style virtual try-on and cloth simulation.     

面向不同体型特征的服装款式迁移方法

大部分成衣的设计以标准比例的人模作为参照,而对于非标准体型的顾客,标码 服装的大小尺寸则很难与之进行有效匹配。基于此,提出了一种面向不同体型特征的服装款 式迁移方法。首先,对于一批不同款式的服装,通过物理模拟的方式穿着到标模及非标模人 体之上,形成标模试穿的服装实例及非标模试穿的服装实例;其次,使用仿射变换表示同款 服装在标模及非标模下服装实例间的变形映射,并借助主成分分析法求解服装变形,在保留 因体型特征导致的服装形变的基础上,剔除由服装款式信息引起的服装形变;最后,将服装 变形用于标模到非标模的服装款式迁移,并使用平均离散曲率衡量迁移前后服装款式的改变 程度。实验结果表明,迁移后的服装携带了标模服装的款式信息,并保留了非标模服装的体 型特征。     

Physical simulation of wet clothing for virtual humans

We present a technique that simulates wet garments for virtual humans with realistic folds and wrinkles. Our approach combines three new models to allow realistic simulation of wet garments: (1) a simplified saturation model that modifies the masses, (2) a nonlinear friction model derived from previously reported, real-world measurements, and (3) a wrinkle model based on imperfection sensitivity theory. In contrast to previous approaches to wet cloth, the proposed models are supported by the experimental results reported in the textile literature with parameters varying over the course of the simulation. As a result, the wet garment motions simulated by our method are comparable to that of real wet garments. Our approach recognizes the special, practical importance of contact models with human skin and provides a specific skin-cloth friction solution. We evaluate our approach by draping a rotating sphere and simulating a typical garment on a virtual human in the rain. Both of these examples are typical scenarios within computer graphics research.     

A template of ease allowance for garments based on a 3D reverse methodology

Nowadays, with the very competitive environment and the emergence of the mass customization concept, garment design is become a crucial step for clothing companies. Indeed, garments should be designed quickly under controlled costs and perfectly fitted to consumers. No traditional pattern making in 2D matches these new constraints since it requires the production of expensive and time consuming physical prototypes. The study presented in this paper relies on 3D virtual design that lets achieve customized garments. An original image processing method based on ellipses and a reverse methodology using scans of a reference body and garment enables evaluation of the overall 3D ease of the garment. The garment is then designed virtually and the result is checked with a 3D simulation on the reference body.     

Learning‐Based Animation of Clothing for Virtual Try‐On

This paper presents a learning‐based clothing animation method for highly efficient virtual try‐on simulation. Given a garment, we preprocess a rich database of physically‐based dressed character simulations, for multiple body shapes and animations. Then, using this database, we train a learning‐based model of cloth drape and wrinkles, as a function of body shape and dynamics. We propose a model that separates global garment fit, due to body shape, from local garment wrinkles, due to both pose dynamics and body shape. We use a recurrent neural network to regress garment wrinkles, and we achieve highly plausible nonlinear effects, in contrast to the blending artifacts suffered by previous methods. At runtime, dynamic virtual try‐on animations are produced in just a few milliseconds for garments with thousands of triangles. We show qualitative and quantitative analysis of results.     

Designing Personalized Garments with Body Movement

The standardized sizes used in the garment industry do not cover the range of individual differences in body shape for most people, leading to ill-fitting clothes, high return rates and overproduction. Recent research efforts in both industry and academia, therefore, focus on virtual try-on and on-demand fabrication of individually fitting garments. We propose an interactive design tool for creating custom-fit garments based on 3D body scans of the intended wearer. Our method explicitly incorporates transitions between various body poses to ensure a better fit and freedom of movement. The core of our method focuses on tools to create a 3D garment shape directly on an avatar without an underlying sewing pattern, and on the adjustment of that garment's rest shape while interpolating and moving through the different input poses. We alternate between cloth simulation and rest shape adjustment based on stretch to achieve the final shape of the garment. At any step in the real-time process, we allow for interactive changes to the garment. Once the garment shape is finalized for production, established techniques can be used to parameterize it into a 2D sewing pattern or transform it into a knitting pattern.     

Concept design for quality in virtual environment

The early identification of the optimal concept is a critical task of the design process in order to increase the chances of satisfying customers. The challenging aspect of the approach proposed in this work relies in the quality evaluation of virtual prototypes of new industrial products (i.e. concept designs) by adopting a statistical procedure previously applied to service industries. Following this approach, the optimal concept design is defined at the end of a process consisting of five phases: identification of the quality elements of the concept design, classification of the quality elements, generation and quality evaluation of product concepts and, finally, definition of the optimal concept. Currently, virtual reality (VR) environment offers the opportunity to evaluate the characteristics of different virtual prototypes by involving experts and/or customers, overcoming the need for several physical prototypes. On the other side, the dynamics of simulation and the stereoscopic visualization in VR environment provides a more realistic and impressive interaction with virtual prototypes than in CAD environment.

The proposed methodology is fully exploited through two case studies: the choice of the optimal design for a traditional Neapolitan coffee maker, addressed by the Italian designer Riccardo Dalisi, and for a subassembly of a new minicar.     

纤维可控的质感布料三维建模与服装仿真

传统布料和服装动态仿真主要通过网格模型进行模拟,并通过光照、材质和颜色设置进行渲染,布料与服装质感效果通常不能体现.本文提出一种新的基于纤维的质感布料建模与服装仿真算法.首先使用集合球约束粒子扰动的方法模拟纤维轮廓,然后根据纱线加捻的动力学和运动学原理模拟基于纤维的纱线构造方法,接着将纱线经纬编织组织结构与弹簧-质点模型结合起来,构造基于纤维块的织物布料模型,最后通过建立人体混合层次包围盒进行快速碰撞检测,实现由质感布料生成的服装动态仿真.实验结果验证了该方法可靠,有效,生成的布料能体现织物外观纤维级别的细节,对应的服装几何纹理和质感效果得到增强.     

部件化构建的三维服装快速编辑方法

直接设计一个三维服装模型不仅耗时而且需要专业服装设计知识。为简化这一复杂 的建模过程,提出基于部件化构建的三维服装快速编辑方法,其关键在于通过分割和融合的网格 编辑技术从已有的服装模型中快速构建新的三维服装模型。首先按照服装分类分割出不同类型的 服装部件。其次基于分割出的三维服装部件以及已有的服装模型,建立部件间以及部件与模型间 的几何约束关系,把二维均值坐标插值方法应用到三维服装网格融合中,把方程数值求解问题转 化为线性插值问题,避免求解线性方程组。最后根据柔性服装的特征,构造适于柔性服装光滑保 形变换的方法。实验结果表明,该算法在不影响融合效果的前提下可以提高融合的效率,能够有 效地实现三维服装的快速编辑。     

基于DDA的碰撞检测及碰撞仿真

碰撞检测是基于物理的动画,计算机辅助没计,计算机辅助制造,计算几何,虚拟现实,机器人等领域必须解决的关键问题,目前仍是研究热点.非连续变形分析方法是一种较新的土木工程领域的数值模拟技术,可以分析不连续块体的运动.将非连续变形分析方法引入到基于物理动厕领域.在计算辅助设计软件设计的虚拟物理场景下,仿真了汽车撞墙和车辆相撞.仿真结果显示:应用非连续变形分析方法可以成功的实现精确的碰撞检测和模拟真实的碰撞响应,在不连续变形、多块体碰撞仿真方面有较大优势.     

A new design concept: 3D to 2D textile pattern design for garments

‘The word “fashion” is synonymous with the word “change”. Fashion begins with fabrics and fabrics begin with colour’. This famous remark/definition of ‘fashion’ must now be revised in the era of digital technology. In this paper, we propose a novel print design concept, from 3D garments to 2D textiles. By taking advantage of the cutting-edge developments in surface parameterisation, cloth simulation and texture assignment, we develop a computer system that allows designers to create figure-flattering prints directly onto 3D garments, and will output 2D pattern pieces with matched texture that are ready for digital printing and garment production. It reverses the traditional design process from 2D fabrics to 3D garments. The results produced by the proposed method guarantee textural continuity in both garment and pattern pieces. It not only releases apparel makers from the tedious work of matching texture along seams, but also provides users with a new tool to create one-of-a-kind fashion products by designing personalised prints.     

From early draping to haute couture models: 20 years of research

Simulating the complex fashion garments of haute couture can only be reached through an optimal combination of modeling techniques and numerical methods that combines high computation efficiency with the versatility required for simulating intricate garment designs. Here we describe optimal choices illustrated by their integration into a design and simulation tool that allow interactive prototyping of garments along drape motion and comfortability tests on animated postures. These techniques have been successfully used to bring haute couture garments from early draping of fashion designers, to be simulated and visualized in the virtual world.     

Research problems in clothing simulation

Clothing simulation and animation are of great importance in computer animation. If cloth simulations could be improved to the point that they could generate realistic cloth motion in real-time, they would find uses in many aspects of daily life such as in fashion design and manufacturing. The area of cloth simulation and animation is full of technical challenges: creating more realistic results, achieving faster run-times, and developing methods capable of constructing and simulating more complex garments. This paper provides an overview of the key procedures involved in the creation of clothed characters, describes the current state-of-the-art techniques, and proposes the research problems that most require further study. Three technical aspects of cloth simulation are considered in this paper: garment construction, physically based simulation, and collision resolution.     

Detailed wrinkle generation of virtual garments from a single image

The presence of proper wrinkles is important while modeling realistic virtual garments. Unlike previously used full 3D information methods, our approach achieves detailed garment generation from a single image. First, we retrieve a garment image similar to the initial virtual garment based on content-based image retrieval (CBIR) method. Then, we preprocess the image with a combination of human body reshaping, image segmentation and shape recovery, to obtain the 3D wrinkle details. Finally, the garment height are synthesized into the virtual garment. For better suit the posture of the human body, excess garment energy are released to remove the unmatched wrinkles. We apply our method to various styles of virtual garments, and it enable virtual characters in general pose to be dressed in these garments and complete wrinkle generation. Compared with existing garment modeling methods, the experimental results show that the proposed method could quickly capture the realistic wrinkles of virtual garments with less manual operation and achieve more realistic wrinkles for virtual garments.

     

DeepGarment : 3D Garment Shape Estimation from a Single Image

3D garment capture is an important component for various applications such as free‐view point video, virtual avatars, online shopping, and virtual cloth fitting. Due to the complexity of the deformations, capturing 3D garment shapes requires controlled and specialized setups. A viable alternative is image‐based garment capture. Capturing 3D garment shapes from a single image, however, is a challenging problem and the current solutions come with assumptions on the lighting, camera calibration, complexity of human or mannequin poses considered, and more importantly a stable physical state for the garment and the underlying human body. In addition, most of the works require manual interaction and exhibit high run‐times. We propose a new technique that overcomes these limitations, making garment shape estimation from an image a practical approach for dynamic garment capture. Starting from synthetic garment shape data generated through physically based simulations from various human bodies in complex poses obtained through Mocap sequences, and rendered under varying camera positions and lighting conditions, our novel method learns a mapping from rendered garment images to the underlying 3D garment model. This is achieved by training Convolutional Neural Networks (CNN‐s) to estimate 3D vertex displacements from a template mesh with a specialized loss function. We illustrate that this technique is able to recover the global shape of dynamic 3D garments from a single image under varying factors such as challenging human poses, self occlusions, various camera poses and lighting conditions, at interactive rates. Improvement is shown if more than one view is integrated. Additionally, we show applications of our method to videos.     

基于细分曲面的三维服装柔性实体模拟

提出一种基于细分曲面的三维服装柔性实体模拟算法，该算法将整个模拟过程分为两个阶段：首先利用四点细分曲面造型方法生成三维服装刚性曲面，然后在刚性曲面基础上通过引入织物的物理模型来模拟三维服装柔性曲面，通过物理和几何模拟方法有机结合，算法有效解决了复杂衣片间的缝合问题，较大地提高了模拟的计算效率，同时，也提出了一种基于细分曲面层次数据结构的碰撞检测算法，有效提高了模拟速度，提出的算法已全部在所开发的三维虚拟服装试衣系统中得以实现，实验结果表明：该算法具有模拟效率高、交互性强和易于计算机实现等优点。     

布料仿真建模研究进展

布料仿真一直是计算机动画中的研究热点与难点,对提高计算机动画质量以及用户体验具有重要意义,布料是一种非常经典的柔性材料物体,遍布于人们的日常生活中。虚拟世界中虚拟角色强烈的视觉真实感主要来源于逼真的虚拟人物的服装动画,这在很大程度上可以增强用户的体验感,在游戏娱乐、电影电视和动画制作等领域有着十分广泛的应用前景。布料仿真的质量与速度直接决定了计算机动画的整体水平,而布料的模拟水平则起着至关重要的作用。随着计算机软硬件的不断发展和计算机动画市场需求的提高,对布料仿真建模方法的研究受到越来越多的关注,布料仿真建模方法也因此有了较大发展。本文通过回顾布料仿真建模方法的相关工作,对国内外方法的研究进展进行综述,从布料仿真中数值积分方法的改进、多分辨率网格的改进和机器学习方法的使用等方面对布料仿真方法的发展进行简要阐述,并根据不同方法在布料模拟应用上的特性,对几大类改进方法进行了相应的总结与展望。同时选取几种算法进行对比,并给出建议。     

基于角色几何碰撞体估计的实时服装仿真

提出了一种快速处理三维服装仿真中角色与服装碰撞的方法.该方法能够满足交互式实时仿真环境的需求.在预处理阶段,根据蒙皮动画的特点,将角色的几何形状以球和简化凸包等简单碰撞体进行估计.在实时模拟阶段,这些碰撞体跟随骨架运动并代替角色模型网格完成与虚拟服装之间的碰撞处理.此外,为了能够快速计算碰撞响应信息,该方法还利用外围映射机制进一步开发了相交测试的空间局部性.实验结果表明,应用该方法可以有效避免衣片与角色模型之间的相互穿透,同时大幅度地减少碰撞处理计算量.实时仿真系统对于复杂服装网格仍然保持了较高的模拟帧速率.