Synopsis
		sfrrt3d < Fv.rsf > Ft.rsf verb=n pick=2 fill=1 scaleray=1. nray=1 jray=1 gmin=-90 gmax=+90 hmin=0 hmax=180 nt=100 ot=0 dt=0.001 xsou=sf_o(ax) + sf_n(ax)*sf_d(ax)/2 ysou=sf_o(ay) + sf_n(ay)*sf_d(ay)/2 zsou=sf_o(az) + sf_n(az)*sf_d(az)/2 seed=time(NULL)

* 3-D ray tracing w/ random shooting directions
* pcs 2005

Parameters
		float dt=0.001   int fill=1   float gmax=+90   float gmin=-90   float hmax=180   float hmin=0   int jray=1   int nray=1   int nt=100   float ot=0   int pick=2   int scaleray=1.   int seed=time(NULL) random seed   bool verb=n [y/n]   float xsou=sf_o(ax) + sf_n(ax)*sf_d(ax)/2   float ysou=sf_o(ay) + sf_n(ay)*sf_d(ay)/2   float zsou=sf_o(az) + sf_n(az)*sf_d(az)/2