clip: must specify at least one of -l or -g or -s or -e options.

Usage: clip [-v axisx,y,z,...] [-g value] [-l value] [-s nslices[,fraction]] [-sph centerx,y,z,...] [-cyl centerx,y,z,...] [-e] [file.oogl] Reads an OOGL object from file.oogl (or stdin if omitted). Slices it against a (series of) planes whose normal vectors are given by the -v argument (default 1,0,0,0,...). Given -g, selects portions where <point> dot <vector> > <pvalue>. Given -l, selects portions where <point> dot <vector> < <nvalue>. Given both, takes the portion lying between those two values. With -s, emits a series of slices spaced <spacing> units apart. With -e, emits just two numbers instead of geometry: range of function-values which the object spans. -sph : Slice against a sphere, not a plane. -g/-l gives radius. -cyl x,y,z... : Slice against a cylinder whose axis passes through x,y,z... -v gives axis direction, -g/-l radius.