Towards embodied perspective: exploring first-person, stereoscopic, 4K, wall-sized rendering of embodied sculpting

Treball realitzat a Kungliga Tekniska HögskolanDevelopment of a technology which allowed an unobtrusive, practical and effective embodied perspective to be experienced by users by the single use of a Kinect sensor and a stereoscopic screen. Applied to virtual sculpting

Emotional Facial Expression Based On Action Units and Facial Muscle

The virtual human play vital roles in virtual reality and game. The process of Enriching the virtual human through their expression is one of the aspect that most researcher studied and improved. This study aims to demonstrate the combination of facial action units (FACS) and facial muscle to produce a realistic facial expression. The result of experiment succeed on producing particular expression such as anger, happy, sad which are able to convey the emotional state of the virtual human. This achievement is believed to bring full mental immersion towards virtual human and audience. The future works will able to generate a complex virtual human expression that combine physical factos such as wrinkle, fluid dynamics for tears or sweating

Digital sculpture : conceptually motivated sculptural models through the application of three-dimensional computer-aided design and additive fabrication technologies

Thesis (D. Tech.) - Central University of Technology, Free State, 200

Virtual prototyping with surface reconstruction and freeform geometric modeling using level-set method

More and more products with complex geometries are being designed and manufactured by computer aided design (CAD) and rapid prototyping (RP) technologies. Freeform surface is a geometrical feature widely used in modern products like car bodies, airfoils and turbine blades as well as in aesthetic artifacts. How to efficiently design and generate digital prototypes with freeform surfaces is an important issue in CAD. This paper presents the development of a Virtual Sculpting system and addresses the issues of surface reconstruction from dexel data structures and freeform geometric modeling using the level-set method from distance field structure. Our virtual sculpting method is based on the metaphor of carving a solid block into a 3D freeform object using a 3D haptic input device integrated with the computer visualization. This dissertation presents the result of the study and consists primarily of four papers --Abstract, page iv

Processes of Artefact Creation in the Hybrid-Reality Engaging with Materials through Material Oxymorons

Yet the nature of all these things must of course be physical since otherwise they could not impress our senses - for impression means touch, and touch means the touch of bodies. Lucrezio, "De Rerum Natura". The materiality of things represents the connection between our bodies and the physical world. However, in recent years, with the overlay of a new digital reality onto the existing physical one, materiality has extended its domain of existence into the virtual world through haptic technologies. The sense of touch is no longer restricted to a physical contact with any kind of "thing" existing in our world, but accessed through perception of it. By means of neurocognitive processes, which reproduce the sense of touch by stimulating particular areas of our brain, touch lost its direct and instinctive connection with the physical world to rely more on mnemonic processes of virtual perception that construct hybrid knowledge based on digital rather than physical stimuli. This paper investigates what the human relationship with things is in the age of human sense simulation. Also, what kind of sensuous relationship is established with our surroundings when the main territory of material investigation has shifted to the virtual, understood as "real"? This paper will attend to human-object/thing relationships via the concept of the "material oxymoron". An oxymoron is a figure of speech that juxtaposes elements that appear to be contradictory. The "material oxymoron" finds its hybrid materiality by means of the human’s perception of, and engagement, with things. By embracing the hybrid context (between the digital and the physical) in which we dwell, we would like to define a new kind of relationship between humans and objects/things using Malafouris' theory of “material engagement”. We will articulate the process through which material oxymorons are constructed, and consider the role of material engagement theory in explaining it. In the material oxymoron, the surface quality is no longer defined a priori in reference to information stored in the human brain, i.e. what we expect, but emerges from the process through which material oxymorons are created. We will therefore treat materials as mutable things, continually transformed by humans and material actants, rather than treating them as objects existing ad infinitum. By means of material oxymoron we aim to challenge a sensuous discovery of the physical whose outcome creates composite matter, i.e. a materiality that fosters human perception and engagement with the physical world

The affordances of 3D and 4D digital technologies for computerized facial depiction

3D digital technologies have advanced rapidly over recent decades and they can now afford new ways of interacting with anatomical and cultural artefacts. Such technologies allow for interactive investigation of visible or non-observable surfaces, haptic generation of content and tactile experiences with digital and physical representations. These interactions and technical advances often facilitate the generation of new knowledge through interdisciplinary and sympathetic approaches. Scientific and public understanding of anatomy are often enhanced by clinical imaging technologies, 3D surface scanning techniques, 3D haptic modelling methods and 3D fabrication systems. These digital and haptic technologies are seen as non-invasive and allow scientists, artists and the public to become active investigators in the visualisation of, and interaction with, human anatomy, remains and histories. Face Lab is a Liverpool John Moores University research group that focuses on creative digital face research; specifically the further development of a 3D computerized craniofacial depiction system, utilizing 3D digital technologies in facial analysis and identification of human remains for forensic investigation, or historical figures for archaeological interpretation. This chapter explores the affordances of such interactions for the non-destructive production of craniofacial depiction, through a case-study based exploration of Face Lab workflow

Direct fabrication through electron beam melting technology of custom cranial implants designed in a phantom based haptic

Repairing critical human skull injuries requires the production and use of customized cranial implants and involves the integration of computer aided design and manufacturing (CAD and CAM). The main causes for large cranial defects are trauma, cranial tumors, infected craniotomy bone flaps and external neurosurgical decompression. The success of reconstructive cranial surgery depends upon: the preoperative evaluation of the defect, the design and manufacturing of the implant, and the skill of the operating surgeon. Cranial implant design is usually carried out manually using CAD although this process is very time-consuming and the quality of the end product depends wholly upon the skill of the operator. This paper presents an alternative automated method for the design of custom-made cranial plates in a PHANToM \uae-based haptic environment, and their direct fabrication in biocompatible metal using electron beam melting (EBM) technology

Collision Detection and Merging of Deformable B-Spline Surfaces in Virtual Reality Environment

This thesis presents a computational framework for representing, manipulating and merging rigid and deformable freeform objects in virtual reality (VR) environment. The core algorithms for collision detection, merging, and physics-based modeling used within this framework assume that all 3D deformable objects are B-spline surfaces. The interactive design tool can be represented as a B-spline surface, an implicit surface or a point, to allow the user a variety of rigid or deformable tools. The collision detection system utilizes the fact that the blending matrices used to discretize the B-spline surface are independent of the position of the control points and, therefore, can be pre-calculated. Complex B-spline surfaces can be generated by merging various B-spline surface patches using the B-spline surface patches merging algorithm presented in this thesis. Finally, the physics-based modeling system uses the mass-spring representation to determine the deformation and the reaction force values provided to the user. This helps to simulate realistic material behaviour of the model and assist the user in validating the design before performing extensive product detailing or finite element analysis using commercially available CAD software. The novelty of the proposed method stems from the pre-calculated blending matrices used to generate the points for graphical rendering, collision detection, merging of B-spline patches, and nodes for the mass spring system. This approach reduces computational time by avoiding the need to solve complex equations for blending functions of B-splines and perform the inversion of large matrices. This alternative approach to the mechanical concept design will also help to do away with the need to build prototypes for conceptualization and preliminary validation of the idea thereby reducing the time and cost of concept design phase and the wastage of resources

Suction force-suction distance relation during aspiration thrombectomy for ischemic stroke: A computational fluid dynamics study

Acute Ischemic Stroke (AIS) is the major type of stroke occurring in patients. Aspiration thrombectomy, which uses suction to remove the thrombosis, is a promising technique in the clinical treatment of AIS patients. In this research a computational fluid dynamics (CFD) analysis was conducted to model the blood flow dynamics in a simplified cerebral model during an aspiration thrombectomy procedure. The flow system being analysed was a typical in vitro cerebral flow model, and the system parameters were set based on the clinical and in vitro data reported in open literature. The simulated flow field features showed good correlation with the in vitro response as reported in literature. The CFD study provides detailed technical data including the peak velocity occurring at the catheter tip and the suction force/suction distance relation during the aspiration thrombectomy procedure, which are useful new knowledge and have the potential to influence future catheter design as well as clinical operational protocols used during thrombectomy intervention