substrate(6) XScreenSaver manual substrate(6)

substrate - Grow crystal-like lines on a computational substrate

substrate [-display host:display.screen] [-foreground color] [-background color] [-wireframe] [-max-cycles cyclecount] [-growth-delay delayms] [-initial-cracks numinitial] [-max-cracks nummax] [-sand-grains numgrains] [-circle-percent circlepercent] [-fps]

Lines like crystals grow on a computational substrate. A simple perpendicular growth rule creates intricate city-like structures. Optionally, cracks may also be circular, producing a cityscape more familiar to places for which city planning is a distant, theoretical concern.

substrate accepts the following options:

Don't draw sand-painting colored effects, only make a wireframe.
Maximum number of growth cycles before restarting. The higher this is, the more complex the art.
Delay in ms between growth cycles. More delay, slower (but smoother and less CPU intensive) art.
Initial number of cracks in the substrate
Maximum number of cracks in the substrate at a single time
Number of sand grains dropped during coloring. More grains cause a denser colour but use more cpu power.
The percentage of the cracks will be circular.
Display the current frame rate and CPU load.

to get the default host and display number.
to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.

X(1), xscreensaver(1)

Copyright © 2003 by J. Tarbell <>.
XScreenSaver port: Mike Kershaw <>

J. Tarbell <>, Jun 2003.
Mike Kershaw <>, Oct 2004.

6.04 (29-May-2022) X Version 11