3-D Imaging

 Would anyone know an easy-to-learn program that allows for visualizing data
 from a file in 3-dimension Euclidean space something that looks like a fluid
 dynamics simulation?  I started to write such a piece of code using Tcl/Tk but
 speed is of the essence (as always).
 Thanks in advance.
 Iraj Daizadeh
 Department of Chemistry
 University of California
 Davis, CA 95616