Virtual reality based creation of concept model designs for CAD systems

This work introduces a novel method to overcome most of the drawbacks in traditional methods for creating design models. The main innovation is the use of virtual tools to simulate the natural physical environment in which freeform. Design models are created by experienced designers. Namely, the model is created in a virtual environment by carving a work piece with tools that simulate NC milling cutters. Algorithms have been developed to support the approach, in which the design model is created in a Virtual Reality (VR) environment and selection and manipulation of tools can be performed in the virtual space. The desianer\u27s hand movements generate the tool trajectories and they are obtained by recording the position and orientation of a hand mounted motion tracker. Swept volumes of virtual tools are generated from the geometry of the tool and its trajectories. Then Boolean operations are performed on the swept volumes and the initial virtual stock (work piece) to create the design model. Algorithms have been developed as a part of this work to integrate the VR environment with a commercial CAD/CAM system in order to demonstrate the practical applications of the research results. The integrated system provides a much more efficient and easy-to-implement process of freeform model creation than employed in current CAD/CAM software. It could prove to be the prototype for the next-generation CAD/CAM system

Supporting Focus and Context Awareness in 3D Modeling Using Multi-Layered Displays

Although advances in computer technology over the past few decades have made it possible to create and render highly realistic 3D models these days, the process of creating these models has remained largely unchanged over the years. Modern 3D modeling software provide a range of tools to assist users with creating 3D models, but the process of creating models in virtual 3D space is nevertheless still challenging and cumbersome. This thesis, therefore, aims to investigate whether it is possible to support modelers more effectively by providing them with alternative combinations of hardware and software tools to improve their 3D modeling tasks. The first step towards achieving this goal has been to better understand the type of problems modelers face in using conventional 3D modeling software. To achieve this, a pilot study of novice 3D modelers, and a more comprehensive study of professional modelers were conducted. These studies resulted in identifying a range of focus and context awareness problems that modelers face in creating complex 3D models using conventional modeling software. These problems can be divided into four categories: maintaining position awareness, identifying and selecting objects or components of interest, recognizing the distance between objects or components, and realizing the relative position of objects or components. Based on the above categorization, five focus and context awareness techniques were developed for a multi-layer computer display to enable modelers to better maintain their focus and context awareness while performing 3D modeling tasks. These techniques are: object isolation, component segregation, peeling focus, slicing, and peeling focus and context. A user study was then conducted to compare the effectiveness of these focus and context awareness techniques with other tools provided by conventional 3D modeling software. The results of this study were used to further improve, and evaluate through a second study, the five focus and context awareness techniques. The two studies have demonstrated that some of these techniques are more effective in supporting 3D modeling tasks than other existing software tools

Computer 3D visualization technology: dynamic design representation tool in solving design and communication problems in the early phases of the architectural design process

Paralleling with development of computer technology, Computer-Aided Design (CAD) has been researched and introduced into industry since the 1960s. Until the mid-1980s, CAD means Computer-Aided Drafting in architectural field because the majority of practicing architects originally used computer as an electronic drafting tool to produce construction drawings. However, now computer 3D visualization technology as a design aided tool is impacting the architectural design process. In this research, a review of architectural representation in the early design phases is given. Additionally, a literature review of CAD development is presented as well. As a focus of this research, computer 3D visualization technology has been researched as a design aid. The emerging use of computer 3D visualization technology in some educational settings is also reviewed. Within this research, three Case Studies are presented to provide insights of how computer 3D visualization technology may impact architectural design process, design service quality, and client-architect?s relationship

Interactive Collaboration Platform in Augmented Reality

Várias ferramentas são utilizadas para a colaboração remota. No entanto, estas restringem o utilizador a um espaço virtual reduzido e não permitem uma interação com o mundo físico remoto. Este projeto propõe uma framework de Realidade Aumentada (AR) para colaboração remota, em que o utilizador remoto cria instruções num espaço virtual 3D que imita o ambiente do utilizador local. As instruções são apresentadas ao utilizador local usando realidade aumentada, ligando o mundo real ao virtual. O utilizador local tenta executar as tarefas de acordo com as instruções virtuais. Subsequentemente, o utilizador remoto recebe o feedback de volta, e, se positivo, continua com um novo conjunto de instruções.Numerous tools are used for remote collaboration, however, they restrict the users to a very confined virtual space and restrain interaction with the remote physical world. This project proposes an Augmented Reality (AR) framework for remote collaboration, in which the remote user creates instructions in a 3D virtual space which mimics the local user's environment. The instructions are then presented to the local user using augmented reality, linking the virtual and real world. The local user tries to execute the task according to the virtual instructions. Subsequently, the remote user receives feedback back and, if positive, proceeds with the next set of instructions

Constructing 3D faces from natural language interface

This thesis presents a system by which 3D images of human faces can be constructed using a natural language interface. The driving force behind the project was the need to create a system whereby a machine could produce artistic images from verbal or composed descriptions. This research is the first to look at constructing and modifying facial image artwork using a natural language interface. Specialised modules have been developed to control geometry of 3D polygonal head models in a commercial modeller from natural language descriptions. These modules were produced from research on human physiognomy, 3D modelling techniques and tools, facial modelling and natural language processing. [Continues.

A real-time virtual-hand recognition system.

by Tsang Kwok Hang Elton.Thesis submitted in: December 1998.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 78-83).Abstract also in Chinese.Chapter 1 --- Introduction --- p.1Chapter 2 --- Virtual-hand Recognition --- p.5Chapter 2.1 --- Hand model --- p.6Chapter 2.1.1 --- Hand structure --- p.6Chapter 2.1.2 --- Motions of the hand joints --- p.8Chapter 2.2 --- Hand-tracking technologies --- p.9Chapter 2.2.1 --- Glove-based tracking --- p.10Chapter 2.2.2 --- Image-based tracking --- p.12Chapter 2.3 --- Problems in virtual-hand recognition --- p.13Chapter 2.3.1 --- Hand complexity --- p.13Chapter 2.3.2 --- Human variations --- p.13Chapter 2.3.3 --- Immature hand-tracking technologies --- p.14Chapter 2.3.4 --- Time-varying signal --- p.14Chapter 2.3.5 --- Efficiency --- p.14Chapter 3 --- Previous Work --- p.16Chapter 3.1 --- Posture and gesture recognition algorithms --- p.16Chapter 3.1.1 --- Template Matching --- p.17Chapter 3.1.2 --- Neural networks --- p.18Chapter 3.1.3 --- Statistical classification --- p.20Chapter 3.1.4 --- Discontinuity matching --- p.21Chapter 3.1.5 --- Model-based analysis --- p.23Chapter 3.1.6 --- Hidden Markov Models --- p.23Chapter 3.2 --- Hand-input systems --- p.24Chapter 3.2.1 --- Gesture languages --- p.25Chapter 3.2.2 --- 3D modeling --- p.25Chapter 3.2.3 --- Medical visualization --- p.26Chapter 4 --- Posture Recognition --- p.28Chapter 4.1 --- Fuzzy concepts --- p.28Chapter 4.1.1 --- Degree of membership --- p.29Chapter 4.1.2 --- Certainty factor --- p.30Chapter 4.1.3 --- Evidence combination --- p.30Chapter 4.2 --- Fuzzy posture recognition system --- p.31Chapter 4.2.1 --- Objectives --- p.32Chapter 4.2.2 --- System overview --- p.32Chapter 4.2.3 --- Input parameters --- p.33Chapter 4.2.4 --- Posture database --- p.36Chapter 4.2.5 --- Classifier --- p.37Chapter 4.2.6 --- Identifier --- p.40Chapter 5 --- Performance Evaluation --- p.42Chapter 5.1 --- Experiments --- p.42Chapter 5.1.1 --- Accuracy analysis --- p.43Chapter 5.1.2 --- Efficiency analysis --- p.46Chapter 5.2 --- Discussion --- p.48Chapter 5.2.1 --- Strengths and weaknesses --- p.48Chapter 5.2.2 --- Summary --- p.50Chapter 6 --- Posture Database Editor --- p.51Chapter 6.1 --- System architecture --- p.51Chapter 6.1.1 --- Hardware configuration --- p.51Chapter 6.1.2 --- Software tools --- p.53Chapter 6.2 --- User interface --- p.54Chapter 6.2.1 --- Menu bar --- p.55Chapter 6.2.2 --- Working frame and data frame --- p.56Chapter 6.2.3 --- Control panel --- p.56Chapter 7 --- An Application: 3D Virtual World Modeler --- p.59Chapter 7.1 --- System Design --- p.60Chapter 7.2 --- Common operations --- p.62Chapter 7.3 --- Virtual VRML Worlds --- p.65Chapter 8 --- Conclusion --- p.70Chapter 8.1 --- Summaries on previous work --- p.70Chapter 8.2 --- Contributions --- p.73Chapter 9 --- Future Work --- p.75Bibliography --- p.7