Span filtering: an optimization scheme for volume visualization of large finite element models

Techniques for displaying 3D isovalues of scalar fields such as stress within a solid finite-element model generally involve examining each element for values of interest. An inexpensive, straightforward method is discussed for reducing the number of elements searched for such isovalues. It takes advantage of one traversal of the element data to yield a compact classification of the model by result values and ranges, with no sorting required. This data structure can then relate any scalar isovalue to a set of element groups which are closely inclusive of the isovalue. This method is intended for applications requiring repeated access to the analysis data, such as animation and interactive rendering of isosurfaces and scalar fields. While applicable to general volume visualization problems, it is particularly well suited to optimizing real-valued continuum field results such as those found in finite-element data