--- ray/src/util/disk2square.cal	2014/07/21 15:59:47	2.1
+++ ray/src/util/disk2square.cal	2014/07/22 23:21:56	2.2
@@ -1,4 +1,4 @@
-{ RCSid $Id: disk2square.cal,v 2.1 2014/07/21 15:59:47 greg Exp $ }
+{ RCSid $Id: disk2square.cal,v 2.2 2014/07/22 23:21:56 greg Exp $ }
 {
 	Convert between unit square and disk, using Shirley-Chiu mapping
 
@@ -73,15 +73,15 @@ out_square_y = (out_square_b + 1)/2;
 }
 
 				{ Compute oriented axis values }
-inc_dot = -Dx*Nx-Dy*Ny-Dz*Nz;
+inc_dz = -Dx*Nx-Dy*Ny-Dz*Nz;
 inc_rx = -Dx*(Uy*Nz-Uz*Ny) - Dy*(Uz*Nx-Ux*Nz) - Dz*(Ux*Ny-Uy*Nx);
-inc_ry = -Dx*Ux-Dy*Uy-Dz*Uz - inc_dot*(Nx*Ux+Ny*Uy+Nz*Uz);
+inc_ry = -Dx*Ux-Dy*Uy-Dz*Uz - inc_dz*(Nx*Ux+Ny*Uy+Nz*Uz);
 inc_den2 = inc_rx*inc_rx + inc_ry*inc_ry;
-inc_radf = if(inc_den2-1e-7, sqrt((1 - inc_dot*inc_dot)/inc_den2), 0);
+inc_radf = if(inc_den2-1e-7, sqrt((1 - inc_dz* inc_dz)/inc_den2), 0);
 				{ Pass to formulas in first section }
 in_disk_x = inc_rx*inc_radf;
 in_disk_y = inc_ry*inc_radf;
 				{ Compute final bin (-1 if behind surface) }
-scbin = if(inc_dot,
+scbin = if(inc_dz,
 		floor(out_square_x*SCdim)*SCdim + floor(out_square_y*SCdim),
 		-1);