source: utils/developer/tcl/showsurface.tcl

#!/usr/bin/tclsh
#
# This scripts parsed a tecplot style file of triangles and displays them via VMD's graphics interface

# fname is the filename of the tecplot .dat file
proc show_surface { fname } {
        draw delete all
        # open file
        set file [open $fname r]
        gets $file title
        gets $file variables
        gets $file zone
        # parse nodes
        set ncount 1
        gets $file line
        while { $line != {} } {
                set nodes($ncount) $line
                incr ncount
                gets $file line
        }
        set ncount [ expr $ncount -1 ]
        puts "There are $ncount nodes."
        # there's a blank line in between
        # parse triangles
        set tcount 0
        gets $file line
        while { $line != {} } {
                set triangles [ split $line " "]
                set first [ lrange $nodes([ lindex $triangles 0 ]) 0 2 ]
                set second [ lrange $nodes([ lindex $triangles 1 ]) 0 2 ]
                set third [ lrange $nodes([ lindex $triangles 2 ]) 0 2 ]
                draw material Transparent
                draw color blue2
                draw triangle $first $second $third
                incr tcount
                gets $file line
        }
        puts "There are $tcount triangles."
}