Context-aware volume navigation

Abstract

Figure 1: Three subsequent screenshots as made during the usage of our image-based volume navigation metaphor. Without changing the navigation mode, the user is able to inspect the data set in a behavior similar to a trackball and can also fly through internal structures when a collision detection is present. To support the spatial-awareness, appropriate thumbnails are displayed. ABSTRACTThe trackball metaphor is exploited in many applications where volumetric data needs to be explored. Although it provides an intuitive way to inspect the overall structure of objects of interest, an in-detail inspection can be tedious -or when cavities occur even impossible. Therefore we propose a context-aware navigation technique for the exploration of volumetric data. While navigation techniques for polygonal data require information about the rendered geometry, this strategy is not sufficient in the area of volume rendering. Since rendering parameters, e.g., the transfer function, have a strong influence on the visualized structures, they also affect the features to be explored. To compensate for this effect we propose a novel image-based navigation approach for volumetric data. While being intuitive to use, the proposed technique allows the user to perform complex navigation tasks, in particular to get an overview as well as to perform an in-detail inspection without any navigation mode switches. The technique can be easily integrated into raycasting based volume renderers, needs no extra data structures and is independent of the data set as well as the rendering parameters. We will discuss the underlying concepts, explain how to enable the navigation at interactive frame rates using OpenCL, and evaluate its usability as well as its performance.

GPU based multi-histogram volume navigation for virtual bronchoscopy

“…We propose a prototype navigation system that utilizes the GPU based multi-histogram to render a clear bronchial airway in a pure volumetric context, without any 3D surface rendering involved. The proposed system overcomes the GPU volume navigation constraint [9] imposed by the traditional game engine based medical simulation architecture. It can generate a trajectory path with a simple path planning tool, allowing users to fly-thru the airway easily and efficiently.…”

“…A linear interpolation is used to estimate the intersection between a ray and iso-surfaces in order to reduce resampling artifacts. Diepenbrock et al [9] proposed a GPU based volume raycaster that generates two proxy geometries, a cube one for rendering, and a sphere one to map the user’s input to camera movement. An image analyzer overlays the two for final rendering.…”

“…The framework utilizes the WildMagic [14] game engine to handle the rendering. In general, 3D camera control in computer games has only limited use in the area of volume rendering [9] because the game engine based rendering pipeline leads to a substantial problem with volume navigation on the GPU. We developed a work around method to solve the problem, which is presented as the following: 1) overview of the GPU based rendering architecture; 2) explanation of the bottleneck GPU rendering constraint in the context of volume navigation; 3)the work around method;4) basic functionalities of a prototype bronchoscopy navigation system.…”

A Sketch-Line Interaction Model for Image Slice-Based Examination and Region of Interest Delineation of 3D Image Data

“…This technique is fairly intuitive and easy to use but can have side effects [18]. One disadvantage is that the user can orient the 3D object in such way that is difficult to return to a previous state.…”

A Multi-Criteria Approach to Camera Motion Design for Volume Data Animation

“…Wan et al [34] also used a distance from boundary field to extract the centerline of volume structures to achieve interactive and automatic fly-through navigation in a volumetric environment. Diepenbrock et al [11] presented an image-based navigation technique that aids user exploration of volume data by avoiding collisions with opaque material. However, these distance field-or imagebased navigation methods are essentially designed for particular types of medical data, and cannot be used in general volume data which usually contains sparse or semi-transparent regions.…”