--- ray/src/rt/m_wgmdf.c	2024/12/19 23:25:28	2.8
+++ ray/src/rt/m_wgmdf.c	2024/12/20 16:29:50	2.9
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: m_wgmdf.c,v 2.8 2024/12/19 23:25:28 greg Exp $";
+static const char RCSid[] = "$Id: m_wgmdf.c,v 2.9 2024/12/20 16:29:50 greg Exp $";
 #endif
 /*
  *  Shading function for programmable Ward-Geisler-Moroder-Duer material.
@@ -452,7 +452,7 @@ dirwgmdf(SCOLOR scval, void *uwp, FVECT ldir, double o
 		 */
 						/* add source width if flat */
 		if (wp->specfl & SP_FLAT)
-			au2 = av2 = omega * (0.25/PI);
+			au2 = av2 = (1. - dstrsrc) * omega * (0.25/PI);
 		else
 			au2 = av2 = 0.0;
 		au2 += wp->rs.u_alpha*wp->rs.u_alpha;