SHAPEFILES is a directory where, as its name suggests, shape files are stored. Out of the many shape files that can be stored in SHAPEFILES, SPC will only use one shape model at a time and that is SHAPE.TXT.
SHAPE.TXT is the main shape model that all of SPC uses. The first line is the Q size (between 8 and 512 in factor of 2 increments: 8, 16, 32, 64, 128, 256, 512). The shape is in the ICQ format, which is basically a 6 sided cube.
Each subsequent line gives the vector of the surface. Bob has made a new routine (equalize) that helps distribute the vectors evenly. The vectors are in Cartesian space (x, y, z).
SHAPE00.TXT is the "baseline" shape model. This can be used to keep track of how far the new shape gets from the starting shape. Usually, it is turned off part way through the mission by INIT_LITHOS.TXT.
A useful tip for the user is to use a symbolic link to specific the SHAPE.TXT. Thus, the user can keep a useful filename in the directory, but "link" that to SHAPE.TXT so SPC works.
How to Link Models
cd SHAPEFILES ln -s <realfile> SHAPE.TXT
Example of a Shape Model
512 -278.04003 278.04003 268.57872 -276.88948 278.59369 269.11354 -275.73912 279.14388 269.64501 -274.58894 279.69061 270.17314 -273.43898 280.23391 270.69794 -272.28923 280.77377 271.21943 -271.13971 281.31022 271.73763 -269.99043 281.84328 272.25255 -268.84141 282.37296 272.76420 -267.69265 282.89927 273.27260 ...