Volume rendering includes techniques for visualizing 3D scalar fields. One common technique is
isocontouring, which extracts constant valued surfaces from 3D scalar fields. Another alternative is
to directly render the 3D data. Methods which directly render scalar volume data are generally
referred to as forward projection or backward projection methods. Forward projection methods
project samples of the 3D field to the screen, usually using traditional graphics techniques
commonly found in hardware. Such techniques are sometimes referred to as splatting techniques.
Backward projection methods determing the color of each pixel by finding the subset of the 3D
field which project to the pixel being colored, and combining them in one of several ways. Such
techniques are commonly referred to as volume raycasting methods.
Cadaver
torso
Rendered by volumetric raycasting with transparent skin and
bone transfer function. Computation was distributed over a
cluster of 4 SGI and Sun workstations. Data volume was 512 x
512 x 400.
Poship
A high-potential iron protein rendered with a standard hue
(blue-red) colormap and linear transparency function
Volume Rendering
