Most of the current
efforts in the visualization of weather forecasting simulations rely on
the standard isosurface. An example of the isosurface on cloud water at
the threshold of 0.00016 is shown on the left or its animation.
(The dataset is courtesy of Dr.
Lloyd A. Treinish at IBM Thomas
J. Watson Research Center.) However, while coherent regions are visible,
no visual cues and quantification information about the regions are available.
A feature-based approach performs segmentation and feature tracking techniques to compute these regions and their properties, and follow their evolution over time. The tracking information can be used to provide enhanced surface visualization. Isosurfaces can be assigned colors to match properties of the object evolution. In the example shown below, a particular region in all the timesteps is assigned the same color. When features merge, the feature with larger volume establishes the color.
click 
for
an mpeg movie.
If the evolution of only one feature is of interest, it can be isolated and highlighted. In the following two examples, the purple object in t=7 is followed, the other objects are given either dull color or removed.
click for
an mpeg movie.
click for
an mpeg movie.
When a feature's history is desired, it can also be traced back. In this example, the light green feature in t=144 is traced back and isolated.
click for
an mpeg movie.
click for
an mpeg movie.
Statistics and measurements are very important to aid in the understanding and analysis of the simulation. Two examples are shown below.
Total
Number of Objects vs Time
Volume
change of the purple object from t=7 to t=50
