pretty simple really

start with the header of "PMF",0x1A,1,0,0,0

then there's a uint32_t denoting how many body parts there are

then, for each body part,
there's a null-terminated 16-byte string (max 15 chars) denoting the part

then there's a uint32_t denoting how many points there are in this body part

then there's a whole bunch of this:

uint16_t radius;
int16_t x,y,z;
uint8_t b,g,r,reserved;

rinse, lather, repeat

units are 8:8 fixed point in terms of the vxl grid by default

"reserved" needs to be 0 or else you suck
NO SIDECHANNELING YOUR NAME IN THERE
i'm going to enforce this in the loader
and will outright reject files which don't have 0 in ALL of these slots