THREE DIMENSIONAL MODELING AND ANIMATION OF FACIAL EXPRESSIONS

Facial expression and animation are important aspects of the 3D environment featuring human characters. These animations are frequently used in many kinds of applications and there have been many efforts to increase the realism. Three aspects are still stimulating active research: the detailed subtle facial expressions, the process of rigging a face, and the transfer of an expression from one person to another. This dissertation focuses on the above three aspects. A system for freely designing and creating detailed, dynamic, and animated facial expressions is developed. The presented pattern functions produce detailed and animated facial expressions. The system produces realistic results with fast performance, and allows users to directly manipulate it and see immediate results. Two unique methods for generating real-time, vivid, and animated tears have been developed and implemented. One method is for generating a teardrop that continually changes its shape as the tear drips down the face. The other is for generating a shedding tear, which is a kind of tear that seamlessly connects with the skin as it flows along the surface of the face, but remains an individual object. The methods both broaden CG and increase the realism of facial expressions. A new method to automatically set the bones on facial/head models to speed up the rigging process of a human face is also developed. To accomplish this, vertices that describe the face/head as well as relationships between each part of the face/head are grouped. The average distance between pairs of vertices is used to place the head bones. To set the bones in the face with multi-density, the mean value of the vertices in a group is measured. The time saved with this method is significant. A novel method to produce realistic expressions and animations by transferring an existing expression to a new facial model is developed. The approach is to transform the source model into the target model, which then has the same topology as the source model. The displacement vectors are calculated. Each vertex in the source model is mapped to the target model. The spatial relationships of each mapped vertex are constrained

Simulation of haemodynamic flow in head and neck chemotherapy

In recent years, intra arterial chemotherapy has become an important component in head and neck cancer treatment. However, therapy success can vary significantly and consistent treatment guidelines are missing. The purpose of this study was to create a computer simulation of the chemical agent injection in the head and neck arteries to investigate the distribution and concentration of the chemical. This is of great interest for medical scientists and vital for prognosis. Realistic three dimensional patient specific geometry was created from image scan data. Engineering principles such as conservation of mass and momentum, turbulence models and a multiphase model were applied in a computational fluid dynamics (CFD) software. At first, a steady cause and effect study with various turbulence and material models was made without the chemical component. It was discovered, that a non-\Newtonian material model is compulsory for blood. The shear stress transport k-w turbulence model is appropriate for the whole velocity range and of superior robustness. These conclusions were used in the following two-component transient simulation. Pulsatile blood flow, turbulence, the chemical agent injection via a catheter and the mixture between blood and the chemical were considered. The principal conclusion was; the modelled catheter position right before the common carotid artery bifurcation produced an ineffective cisplatin distribution consistent throughout all the arteries. Due to high wall shear stress and turbulence at the inner bifurcation wall, serious complications during the treatment could occur, for instance heamolysis or acute vascular endothelial changes. To the best of the author\u27s knowledge a novel \CFD based approach was introduced, suitable for the optimization and the formulation of treatment guidelines in intra arterial injection chemotherapy. After a required validation, this model can be modified to investigate the influence of various catheter positions and dose rate schemes in future simulations

Computer-Assisted Interactive Documentary and Performance Arts in Illimitable Space

This major component of the research described in this thesis is 3D computer graphics, specifically the realistic physics-based softbody simulation and haptic responsive environments. Minor components include advanced human-computer interaction environments, non-linear documentary storytelling, and theatre performance. The journey of this research has been unusual because it requires a researcher with solid knowledge and background in multiple disciplines; who also has to be creative and sensitive in order to combine the possible areas into a new research direction. [...] It focuses on the advanced computer graphics and emerges from experimental cinematic works and theatrical artistic practices. Some development content and installations are completed to prove and evaluate the described concepts and to be convincing. [...] To summarize, the resulting work involves not only artistic creativity, but solving or combining technological hurdles in motion tracking, pattern recognition, force feedback control, etc., with the available documentary footage on film, video, or images, and text via a variety of devices [....] and programming, and installing all the needed interfaces such that it all works in real-time. Thus, the contribution to the knowledge advancement is in solving these interfacing problems and the real-time aspects of the interaction that have uses in film industry, fashion industry, new age interactive theatre, computer games, and web-based technologies and services for entertainment and education. It also includes building up on this experience to integrate Kinect- and haptic-based interaction, artistic scenery rendering, and other forms of control. This research work connects all the research disciplines, seemingly disjoint fields of research, such as computer graphics, documentary film, interactive media, and theatre performance together.Comment: PhD thesis copy; 272 pages, 83 figures, 6 algorithm

Anatomical and functional custom made restoration techniques with Direct Metal Laser Forming technology: systematic workflow and CAD-CAM

Introduction Bone defects are usually repaired by the body’s healing process itself. If severe fracture, tumor or infection occur on large bones, it poses a serious challenge to the regeneration ability of the bones. One of the latest advancement in medical science is the rapid prototyping technologies. Therefore, the aim of the present study was the developing and testing of a reliable workflow to fabricate custom-made grafts in the field craniofacial surgery. Material and Methods In this study 14 patients with different cranio-facial bone defects were enrolled. Two evaluation methods were associated to test the results of the workflow. Surveys were given to patients undergone surgery and their surgeons to have a subjective analysis of the workflow. For each patient the produced prosthesis was superimposed on the original prosthesis design, the displacement between was evaluated. Results Significant level of discomfort at 4 weeks after surgery compared to 2 days after surgery, aesthetic improvement significant improved 1 year after surgery compared to 4 weeks after surgery. Aesthetic improvement 1 year after surgery and aesthetic improvement according to expectations showed correlation, aesthetic improvement 1 year after surgery and aesthetic improvement according to expectations showed correlation. The mean distance of the printed model was significant smaller than the virtual model, with a mean difference of -0.075 mm. Conclusion According to the results of the present study custom made bone graft made with laser sintering technique represents a valid alternative to traditional bone grafts with high clinical accuracy and the advantage to avoid morbidity of the donor site or of the patient due to animal grafting

Evaluation of a custom made anatomical guide for orthognathic surgery

Orthognathic surgery is a routinely used surgical technique for the correction of dento-facial deformities. During a Le Fort I orthognathic procedure the maxilla is surgically separated from the skull and the surgical positioning wafer is placed between the occlusal surfaces of the upper and lower dentition. However, the physiological response to general aesthesia results in loss of muscle tone in the mandible, which has a profound influence on the correct amount of maxillary advancement required. The expertise and visual judgement of the surgeon is relied upon to foresee and eliminate this potential source of error. However, this may not be possible to achieve in all cases, therefore there is a need for a device to guide the surgical position of the maxilla independent of the mandibular dentition. The aim of this study was to design and validate a custom made anatomical repositioning surgical framework for accurately repositioning the maxilla independently of the mandible during a Le Fort I osteotomy. A single plastic anatomical skull was scanned using a helical Computed Tomography (CT) scanner. Utilising 3D manipulation software, forty-three Le Fort I orthognathic surgery movements were planned. A custom made anatomical repositioning guide was designed and 3D printed for all movements. Each guide was used to reposition the maxilla of the physical skull and then laser scanned using a GOM blue light scanner. GOMinspect software was used to compare the planned and physical position of the repositioned maxilla. The results of the experiment were statistically evaluated.Orthognathic surgery is a routinely used surgical technique for the correction of dento-facial deformities. During a Le Fort I orthognathic procedure the maxilla is surgically separated from the skull and the surgical positioning wafer is placed between the occlusal surfaces of the upper and lower dentition. However, the physiological response to general aesthesia results in loss of muscle tone in the mandible, which has a profound influence on the correct amount of maxillary advancement required. The expertise and visual judgement of the surgeon is relied upon to foresee and eliminate this potential source of error. However, this may not be possible to achieve in all cases, therefore there is a need for a device to guide the surgical position of the maxilla independent of the mandibular dentition. The aim of this study was to design and validate a custom made anatomical repositioning surgical framework for accurately repositioning the maxilla independently of the mandible during a Le Fort I osteotomy. A single plastic anatomical skull was scanned using a helical Computed Tomography (CT) scanner. Utilising 3D manipulation software, forty-three Le Fort I orthognathic surgery movements were planned. A custom made anatomical repositioning guide was designed and 3D printed for all movements. Each guide was used to reposition the maxilla of the physical skull and then laser scanned using a GOM blue light scanner. GOMinspect software was used to compare the planned and physical position of the repositioned maxilla. The results of the experiment were statistically evaluated

Proceedings, MSVSCC 2018

Proceedings of the 12th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2018 at VMASC in Suffolk, Virginia. 155 pp

Proceedings, MSVSCC 2012

Proceedings of the 6th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2012 at VMASC in Suffolk, Virginia