This work concerns / deals with theoretical analysis, design and implementation of system for creation three-dimensional computer models of human body tissues. These models will be created by computer tomography (CT) and magnetic resonance (MR) data. Output of medical apparatuses based on these principles is a three-dimensional raster, which is not good for visualization and making real models. For required tissues extraction are used automatic or semiautomatic methods, where is necessary an operation of a specialist. This work is concerned with human body tissues with linear structure such as veins and arteries, nerves, bone canals etc. These structures are problematic recognizable by automatic methods. Therefore is convenient an operation of a specialist, which is adept in human anatomy.

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When creating physics simulations, one common issue that arises is the need to visualize the simulation progress and results. With recent advancements in ray tracing this problem has mostly been solved for non real-time applications. However, there still exists a need to find and evaluate real-timerendering options for applications that need to run at interactive frame rates. In this thesis, we look at some rendering frameworks and propose a set off our performance based metrics and one usability metric for evaluating these. In addition to the metrics, we propose a qualitative method for evaluating the realism of simulated scenes rendered using different frameworks. Finally, we select one of the frameworks and use the metrics and the qualitative method proposed to evaluate the overall fit of the framework for the use case of visualizing physics simulations. The results show similar scores for the performance metrics using the new framework as using a previously used reference framework while showing a slight tendency for increased realism in scenes using the new framework.

This document chronicles the ongoing production of the computer-animated short film Tower 37. It begins with a close examination of the film itself, emphasizing the visual storytelling components that were the core of my MFA work (particularly character performance, camera, and editing). This is followed by a thorough discussion of the mechanism of producing the film: a sequence of experimental courses I have created and taught at Hampshire College over the past two years. The document then discusses my approach to the craft of directing before concluding with evaluative comments and a look ahead.

In computer graphics, algorithms that attempt to create photographic images by simulating light transport are collectively known as Global Illumination methods. The most versatile of these are based on ray tracing (following ray paths through a scene), and numerical integration using random or quasi-random sampling. While ray tracing and sampling methods in global illumination have progressed much in the last two decades, the goal of fast and accurate simulation of light transport remains elusive. This dissertation presents a number of new sampling methods that attempt to address some of the shortcomings of existing global illumination algorithms. The first part of the dissertation concentrates on memory issues related to ray tracing of large scenes. In this part, we present memory-efficient lightweight bounding volumes as a data structure that can substantially reduce the memory overhead of a ray tracer, allowing more complicated scenes to be ray traced without complicated caching schemes. Part two of the dissertation concerns itself with sampling algorithms related to direct lighting, an important subset of global illumination. In this part, we develop two stage importance sampling} to sample the product of the BRDF function and a large light source such as an environment map. We then extend this method to include all three terms of the direct lighting equation, sampling the triple product of the BRDF, lighting and visibility. We show that the new sampling methods have a number of advantages over existing direct lighting algorithms, including comparatively low memory overhead, little precomputation, and the ability to sample all three terms of the direct lighting equation. Finally, the third part of the dissertation discusses sampling algorithms in the context of general global illumination. In this part, we develop two new algorithms that attempt to improve the sampling distribution over existing techniques by exploiting information gained during the course of sampling. The first of these methods, energy redistribution path tracing, works by using path mutation to spread energy, and thus share sampling information, between pixels. The second method, sample swarming, shares information gained during sampling by keeping importance maps for each pixel in the rendered image. Whenever a new pixel is to be rendered, the maps from neighboring pixels are averaged, propagating importance information through the scene. We demonstrate that both of these methods can perform substantially better than existing global illumination algorithms in a number of common rendering contexts.

Procedural generation techniques are able to quickly and cheaply produce large areas of terrain. However, these techniques produce results that are not easily directable and often require artists to edit the results by hand to achieve the desired layout. This paper proposes a sketch-based system for controlling fractal terrain that allows for a wide variety of terrain feature types. Artists sketch features rather than constrained points or elevations. The system is interactive, provides quick on-demand previews of the terrain, and allows for iterative design modifications. Interaction between features is handled in a realistic fashion. An arbitrary vertex insertion order midpoint displacement algorithm is also described which provides the necessary flexibility and constraints for the terrain generation system.

As graphics and simulations become more realistic, techniques for approximating soft body objects, that is, non-solid objects such as liquids, gases, and cloth, are becoming increasingly common. The proposed generalized soft body method encompasses some specific cases of other existing models enabling simulation of a variety of soft body materials by parameter adjustment. This research presents a general method of soft body model and simulation in which parameters for body control, surface deformation, volume control, and gravitation, can be adjusted to simulate different types of soft bodies. In this method, the soft body mesh structure maintains configuration among surface points while fluid modeling deforms the details of the surface. To maintain volume, an internal pressure is approximated by simulated molecules within the soft body. Free fall motion of soft body is generated by gravitational field. Additionally, a constraint is specified based on the property of the soft body being modeled. There are several standard methods to control soft body volume. This work illustrates the simplicity of simulation by selecting a mass-spring system for the deformation of the connected points of a three-dimensional mesh, while an internal pressure force acts upon the surface triangles. To incorporate fluidity, smooth particles hydrodynamics (SPH) is applied where surface points are considered as free moving particles interacting with neighboring surface points within a SPH radius. Because SPH is computationally expensive, it requires an efficient method to determine neighboring surface points. Collision detection with soft bodies and other rigid body objects also requires such fast neighbor detection. To determine the neighboring surface point, Axis Aligned Bounding Box (AABB), Octree, and a partitioning and hashing schemes iv have been investigated and the result shows that the partitioning and hashing scheme provides the best frame rate. Thus a fast partitioning and hashing scheme is used in this research to reduce both computational time and the memory requirements. The proposed soft body model aims to be applied in several types of soft body application depending on the specific types of soft body deformation. The work presented in this dissertation details experiments with a variety of visually appealing fluid-like surfaces and organic materials animated at interactive speeds. The algorithm is also used to implement animated space-blob creatures in the Galactic Arms Race video game and a human lung simulation, demonstrating the effectiveness of the algorithm in both an actual video game engine and a medical application. The simulation results show that the general model of the soft body can be applied to several applications by adjusting the soft body parameters according to the appearance results.