--- ray/src/util/klems_half.cal	2014/07/21 15:59:47	1.2
+++ ray/src/util/klems_half.cal	2022/07/14 02:52:02	1.5
@@ -1,4 +1,4 @@
-{ RCSid $Id: klems_half.cal,v 1.2 2014/07/21 15:59:47 greg Exp $ }
+{ RCSid $Id: klems_half.cal,v 1.5 2022/07/14 02:52:02 greg Exp $ }
 {
 	Compute interior bin for half Klems BSDF basis (0-72)
 	Returns -1 for wrong-side rays
@@ -12,8 +12,8 @@ Acos(x) : if(x-1, 0, if(-1-x, PI, acos(x))) / DEGREE;
 posangle(a) : if(-a, a + 2*PI, a) / DEGREE;
 Atan2(y,x) : posangle(atan2(y,x));
 
-khpola(r) : select(r, 6.5, 19.5, 32.5, 46.5, 61.5, 76.5, 90);
-khnaz(r) : select(r, 1, 8, 12, 16, 20, 12, 4);
+khpola(r) : select(r, 6.5, 19.5, 32.5, 45.5, 58.5, 71.5, 90);
+khnaz(r) : select(r, 1, 8, 12, 16, 20, 12, 8);
 khaccum(r) : if(r-.5, khnaz(r) + khaccum(r-1), 0);
 khfindrow(r, pol) : if(r-khpola(0)+.5, r,
 		if(pol-khpola(r), khfindrow(r+1, pol), r) );
@@ -28,12 +28,13 @@ khbin2(pol,azi) = if(pol-90, -1,
 		khaccum(3) + khazn(azi,360/khnaz(4)),
 		khaccum(4) + khazn(azi,360/khnaz(5)),
 		khaccum(5) + khazn(azi,360/khnaz(6)),
-		khaccum(6) + khazn(azi,360/khnaz(7)),
-		khaccum(7) + khazn(azi,360/khnaz(8))
+		khaccum(6) + khazn(azi,360/khnaz(7))
 	) );
 
+RHS = 1;	{ set to -1 for left-handed system }
+
 khbin(Nx,Ny,Nz,Ux,Uy,Uz) = khbin2(Acos(-Dx*Nx-Dy*Ny-Dz*Nz),
 	Atan2(-Dx*Ux-Dy*Uy-Dz*Uz + (Nx*Dx+Ny*Dy+Nz*Dz)*(Nx*Ux+Ny*Uy+Nz*Uz),
-		-Dx*(Uy*Nz-Uz*Ny) - Dy*(Uz*Nx-Ux*Nz) - Dz*(Ux*Ny-Uy*Nx)));
+		-RHS*(Dx*(Uy*Nz-Uz*Ny) + Dy*(Uz*Nx-Ux*Nz) + Dz*(Ux*Ny-Uy*Nx))));
 				
 Nkhbins : khaccum(khnaz(0));	{ Number of bins for one elevation }