© Steffen Weber, March 1999
This applet lets you play with the symmetry groups to which wall paper patterns belong. In crystallography we call those symmetry groups plane space groups. This applet is based on my DOS program 2DSPGR.
Method
You may load an example image or draw some motif in the motif editor. Upon execution the motif will then be pixelized and the chosen symmetry operations performed on each pixel which is not white!. So simple line drawings should display quite fast. If the motif however covers a large number of pixels the calculation will take longer. Please note that you can try each symmetry group (radio buttons on the right) with the same motif. You may also scale the motif independently from the grid using the motif scale slider. These are the essential differences to another popular applet for plane space groups called EscherWebScetch.
Usage
Colorchooser: drag/click with left mouse button for pen color "p" and with the right mouse button for the background color "b". The background color is only applied in the pattern and not in the motif editor! Both colors are indicated in the little boxes on the right side of the color chooser area.
Then you click draw pattern to calculate and draw the wallpaper pattern. On the right you may choose different symmetry groups by selecting one of the radio buttons. The grid checkbox lets you switch the overlayed grid on/off.