Interactive volume rendering of large scalar fields on mobile devices using subsampling techniques.

Debasish Tapna
ME Thesis


We study the problem of subsampling of 3D scalar fields. Software tools for visualizing 3D scalar fields usually have processing and memory requirements depending upon the size of the scalar field for getting desired interactiveness. Small computing systems such as mobile devices have resource constraints. When the size of the scalar field is large or exceeds the available memory, the visualization tool is unable to achieve a good interactive rate. Appropriate subsampling of the scalar field can alleviate such a problem. The subsampled scalar field should have all the important features of the original scalar field. Topological properties in scalar fields carry important information about the scalar fields itself. So preserving these properties in the subsampled scalar field can help in retaining important features of the original large scalar field. We built a volume render for a mobile device. We propose three subsampling algorithms based on retaining the critical points. A method to evaluate the subsampled scalar fields based on mapping of branches using proximity. We also showed how our algorithms and evaluation method works on some of the dataset.