PLOT3D (also THREED or 3D) makes a 3 dimensional perspective plot of the specified buffer. The viewing altitude and aziumuth can be specified with the ALT= and AZ= terminal; if unspecified, they default to 45 and 225 degrees, respectively. The vertical scale is done automatically, but can be overridden by use of the ZFAC and ZOFF keywords. See the Mongo manual for more details. NOERASE prevents erasure of the screen before making the plot. HARD generates hardcopy.
The 3-D plots that LickMongo makes can take a long time to draw. Once the plot starts, there is no way to stop it until it is completed. Consequently, we suggest that you only use it on small sections of images, smaller than 100 x 100 pixels. The BOX= keyword makes it easy to select small image sections. If you enter an image larger than 100x100, the program will confirm that you really wish to continue before doing so.
Some control over the vertical relief plotted is possible using the ZFAC and ZOFF keywords. These affect how the minimum and maximum data values are fit inside the virtual cube being plotted. By changing these by hand, you can enhance or depress the vertical stretch of the plot (ZFAC) and move the plot up and down vertically within the plotting window (ZOFF).
If these are too arcane for you, then SCALE can be used instead to tweak the defaults computed by the routine from the data values, where SCALE=1 is equivalent to accepting the defaults, SCALE1 will increase relief, and SCALE1 will depress relief.