Avoidance-based ray tracing for volume rendering

摘要

A machine-implemented display method that, with respect to a volume dataset being rendered, enables a user to navigate to any position in space and look in any direction. Preferably, the volume dataset is derived from a computer tomography (CT) or magnetic resonance imaging (MRI) scan. With the described approach, the user can see details within the dataset that are not available using conventional visualization approaches. The freedom-of-motion capability allows the user to go to places (positions) within the volume rendering that are not otherwise possible using conventional “orbit” and “zoom” display techniques. Thus, for example, using the described approach, the display image enables a user to travel inside physical structures (e.g., a patient's heart, brain, arteries, and the like).

主权项

1. An article comprising a tangible, non-transitory machine-readable medium that stores a program, the program being executed by a machine having a hardware component to perform a method, the method comprising:
receiving a volume dataset defining a volume; and rendering, with respect to any position and orientation in the volume, an image of the volume dataset at a given number of frames per second, each frame of the image having a uniform distribution of pixels, at least two frames of an image sequence having varying resolution with respect to one another, and at least two pixels within a particular frame each being associated with a ray having a varying number of ray tracing steps with respect to one another, each ray, as it traverses the volume dataset during rendering, samples the volume dataset along a set of sampling points whose locations along the ray are determined as the ray is cast, wherein, for each pair of sampling points, a location of at least a next sample point along the ray is determined at least in part by a value of at least a voxel at a current sample point, and wherein a distance between two sample locations varies dynamically and in a non-uniform manner by a value equal to an inverse of an absolute value of an avoidance value minus the value of the voxel at the current sample point.