Bilimsel görüntüleme için hacim boyama yöntemleri

Direct volume rendering is widely used in many applications. We explored several aspects of the problem. First, we proposed a view-dependent selective refinement scheme in order to reduce the high computational requirements without affecting the image quality significantly. Then, we explored the parallel implementations of direct volume rendering. Finally, we used direct volume rendering approaches to create a material visualization tool. Achieving interactive rates in volume-rendering applications is a real challenge. We present a selective refinement scheme that dynamically defines the mesh according to the camera parameters. The importance of different parts of the mesh is automatically determined and the mesh is refined accordingly. Thanks to low overhead dynamic view-dependent refinement, we achieve interactive frame rates for rendering common datasets at decent image resolutions. Using CUDA, we propose a GPU-based volume rendering algorithm that is based on a cell projection-based ray-casting algorithm. We favor image quality over rendering speed. Our algorithm has a low memory footprint, allowing us to render large datasets with significant speed-ups. Visualization of materials is an indispensable part of their structural analysis. We developed a visualization tool called MaterialVis. Unlike existing tools, MaterialVis represents materials as a volume and a surface manifold, in addition to plain atomic coordinates. MaterialVis provides a wide range of functionality to visualize topological structures and crystal defects interactively. Direct volume rendering techniques are used to visualize crystal defects. In addition, the tool provides surface visualization to extract hidden topological features within the material.