The FAST module "Tracer" generates particle traces. After reading in a grid file and a vector or a solution file, start this module by pulling down the "Modules" menu in the "Viewer" module to "Tracer". You will see the following
If you are using a vector file, pull the "Options" menu down to "Trace Function" and then slide the mouse to the right and then down to "Use Vec Reg". Here is an example of a simple trace, the vector field was drawn with the "Surfer"
The sliders in the "Tracer" module control the crosshairs, the intersection of the red and green curves. The button "Compute Trace" will draw a single trace from the crosshairs. the button "Compute Rake" will draw a series of traces. Choose the rake direction by selecting some combination of "I", "J" and "K" above the sliders. The picture of the "Tracer" module shows the settings for the trace shown above. Note: There are 10 traces, in the "J" direction, along the 14th grid line in the "I" direction.
Use the "Options" and "Panels" menus to turn the boundary on or off, to turn the crosshairs, top change the color of a trace, and to control the style of the traces.