RESEARCH ON THE VISUALIZATION EXPRESSION OF THE INVISIBLE
DISPERSIVE FEATURE
J. Guo, Z. Tian, F. Cheng
Guojia828@163l.com
Abstract: It is known to all that 3D GIS is the recent trend
in GIS technique, and modeling of 3D
data (i.e. spatial data) is the key problem of 3D GIS. 3D data model includes
surface data model and volume data model, the modeling methods includes facial
modeling and volumetric modeling. The facial modeling method emphasizes
particularly on the surface of the geographic entity, for example, the
landform, the stratum, the outline of the construction and so on. The
volumetric modeling method emphasizes particularly on the interior of the
geographic entity, such as water bodies, orebody, mineral
lines and so on. Recently, with the development of volume visualization, volume
data model becomes one of the most important ways to express the spatial data, it has being used in geology, medicine, meteorology and
remote sensing.
In
this paper, we discuss the visualization expression of the invisible dispersive
feature (such as temperature, density, salinity of sea water and so on). By analyses,
we find what the difference between this invisible feature and the visible
feature mentioned in the last paragraph (such as orebody and mineral lines) is
that the former one is invisible. So we try to express the invisible dispersive
feature by the volumetric modeling method mentioned in the last paragraph.
We
discuss the volumetric modeling method which embodies two types: regular
feature and irregular feature. As to the regular feature, we analyze the CSG-tree,
Octree and Regular Block; as to the irregular feature,
we analyze the TEN, Pyramid, 3D-Voronoi and GTP. By a lot of digital
experimentations, we find their advantages disadvantages and the applying way. In
a word, the appropriate modeling method for the visualization expression of the
invisible dispersive feature should be in accordance with the characteristics
of the invisible dispersive feature.
Keywords: 3D Geographic Data Model, volume data, dispersive feature