--- ray/src/util/rambpos.cal	2014/04/24 23:15:42	2.1
+++ ray/src/util/rambpos.cal	2014/05/09 23:49:05	2.5
@@ -1,32 +1,36 @@
-{ RCSid $Id: rambpos.cal,v 2.1 2014/04/24 23:15:42 greg Exp $ }
+{ RCSid $Id: rambpos.cal,v 2.5 2014/05/09 23:49:05 greg Exp $ }
 {
 	Compute ambient position factors for genambpos.pl
 }
 and(a,b) : if(a,b,a);
 				{ level selector }
-cond = if(LV+.5, and($10-LV-.5,LV+.5-$10), 1);
-px = $1; py = $2; pz = $3;
+lvl = $10;
+wt = $11;
 r0 = SF*$12; r1 = SF*$13;
+acond = and( r0-5e-5, and( wt-MW, if(LV+.5, and(lvl-LV+.5,LV+.5-lvl), 6.5-lvl) ) );
+px = $1; py = $2; pz = $3;
 nx = $4; ny = $5; nz = $6;
 ux = $7; uy = $8; uz = $9;
 vx = ny*uz - nz*uy;
 vy = nz*ux - nx*uz;
 vz = nx*uy - ny*ux;
-avr = $14; avg = $15; avb = $16;
+avr = .5/PI*$14; avg = .5/PI*$15; avb = .5/PI*$16;
 				{ magnified position gradient }
 pgx = ($17*ux + $18*vx)/SF;
 pgy = ($17*uy + $18*vy)/SF;
 pgz = ($17*uz + $18*vz)/SF;
 pg = sqrt(pgx*pgx + pgy*pgy + pgz*pgz);
+pcond = and( acond, pg - .0001 );
 				{ direction gradient }
 dgx = $19*ux + $20*vx;
 dgy = $19*uy + $20*vy;
 dgz = $19*uz + $20*vz;
 val = avr + avg + avb;		{ ambient position color }
-agr = select($10+1, val, 0, 0, val, 0, val, val);
-agg = select($10+1, 0, val, 0, val, val, 0, val/2);
-agb = select($10+1, 0, 0, val, 0, val, val, val/2);
+agr = select(lvl+1, val, 0, 0, val, 0, val, val);
+agg = select(lvl+1, 0, val, 0, val, val, 0, val/2);
+agb = select(lvl+1, 0, 0, val, 0, val, val, val/2);
 psiz = r0/10;
+dcond = and( acond, dgx*dgx+dgy*dgy+dgz*dgz - 1e-8 );
 				{ base polygon vertices }
 px1 = px + r0*ux + r1*vx + .0001*nx;
 py1 = py + r0*uy + r1*vy + .0001*ny;