--- ray/src/gen/skybright.cal	1991/11/12 17:05:15	2.1
+++ ray/src/gen/skybright.cal	1992/03/20 12:23:37	2.2
@@ -8,6 +8,7 @@
      Additional arguments required for calculation of skybright:
 
 	A1			- boolean, positive for cloudy sky
+				  (A1>=2 for cloudy uniform sky)
 	A2			- zenith brightness
 	A3			- ground plane brightness
 	A4			- normalization factor based on sun direction
@@ -19,7 +20,7 @@ skybright = wmean((Dz+1.01)^10, if(A1, cloudysky, sunn
 
 wmean(a, x, b, y) = (a*x + b*y) / (a + b);
 
-cloudysky = A2 * (1 + 2*Dz) / 3;
+cloudysky = A2 * if(A1-1, 1, (1 + 2*Dz)/3);
 
 sunnysky = A2 * (.91 + 10*exp(-3*gamma) + .45*cosgamma*cosgamma)
 	      *  if( Dz - .01, 1.0 - exp(-.32/Dz), 1.0) / A4;