Observation on Methods for Direct Volume Rendering

Direct volume rendering immediately display the datasets into image plane without any intermediate representation. Commonly this method can be classified into image-order techniques represent a backward-mapping scheme and objectorder techniques apply a forward-mapping scheme. By using the image-order methods image is generated pixel-by-pixel casting rays from the view-point through each pixel of the image plane. In contrast to image-order methods, object-order methods loop through the data samples projecting each sample voxel-by-voxel onto the image plane. This paper emphasizes a survey of current direct volume rendering techniques. Through investigations of current literature and systems, we draw an overall picture of significant concepts and ideas. The paper ends with some concluding remarks and suggestions for future development.