This is done by rendering the scene into a small texture, then repeatedly rendering increasingly-enlarged and increasingly-transparent versions of that texture onto the frame buffer. As such, it's quite graphics intensive: don't bother trying to run this if you don't have hardware-accelerated texture support. It will hurt your machine bad.

-visual visual

Specify which visual to use. Legal values are the name of a visual class, or the id number (decimal or hex) of a specific visual.

-window

Draw on a newly-created window. This is the default.

-root

Draw on the root window.

-delay number

Per-frame delay, in microseconds. Default: 10000 (0.01 seconds.).

-blursize number

How many copies of the scene should be laid down to make the vapor trail. Default: 15. Larger numbers create smoother fields, but are slower.

-wander | -no-wander

Whether the object should wander around the screen.

-spin [XYZ]

Around which axes should the object spin?

-no-spin

None.

-fps | -no-fps

Whether to show a frames-per-second display at the bottom of the screen.

DISPLAY

to get the default host and display number.

XENVIRONMENT

to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.