Index: tr_shade.c
===================================================================
--- tr_shade.c	(revision 315)
+++ tr_shade.c	(working copy)
@@ -430,6 +430,7 @@
 	float	radius;
 	vec3_t	floatColor;
 	float	modulate;
+	float	flux;
 
 	if ( !backEnd.refdef.num_dlights ) {
 		return;
@@ -531,37 +532,43 @@
 			vec_ste((vector unsigned int)colorChar,0,(unsigned int *)colors);	// store color
 #else
 			VectorSubtract( origin, tess.xyz[i], dist );
-			texCoords[0] = 0.5f + dist[0] * scale;
-			texCoords[1] = 0.5f + dist[1] * scale;
+			clip = 0;
+			flux = DotProduct(dist, tess.normal[i]);    // If dynamic light is behind surface, turn off.
 
-			clip = 0;
-			if ( texCoords[0] < 0.0f ) {
-				clip |= 1;
-			} else if ( texCoords[0] > 1.0f ) {
-				clip |= 2;
-			}
-			if ( texCoords[1] < 0.0f ) {
-				clip |= 4;
-			} else if ( texCoords[1] > 1.0f ) {
-				clip |= 8;
-			}
-			// modulate the strength based on the height and color
-			if ( dist[2] > radius ) {
-				clip |= 16;
-				modulate = 0.0f;
-			} else if ( dist[2] < -radius ) {
+			if ( flux < 0 ) {
 				clip |= 32;
 				modulate = 0.0f;
 			} else {
-				dist[2] = Q_fabs(dist[2]);
-				if ( dist[2] < radius * 0.5f ) {
-					modulate = 1.0f;
+				texCoords[0] = 0.5f + dist[0] * scale;
+				texCoords[1] = 0.5f + dist[1] * scale;
+
+				if ( texCoords[0] < 0.0f ) {
+					clip |= 1;
+				} else if ( texCoords[0] > 1.0f ) {
+					clip |= 2;
+				}
+				if ( texCoords[1] < 0.0f ) {
+					clip |= 4;
+				} else if ( texCoords[1] > 1.0f ) {
+					clip |= 8;
+				}
+				// modulate the strength based on the height and color
+				if ( dist[2] > radius ) {
+					clip |= 16;
+					modulate = 0.0f;
+				} else if ( dist[2] < -radius ) {
+					clip |= 32;
+					modulate = 0.0f;
 				} else {
-					modulate = 2.0f * (radius - dist[2]) * scale;
+					dist[2] = Q_fabs(dist[2]);
+					if ( dist[2] < radius * 0.5f ) {
+						modulate = 1.0f;
+					} else {
+						modulate = 2.0f * (radius - dist[2]) * scale;
+					}
 				}
+				clipBits[i] = clip;
 			}
-			clipBits[i] = clip;
-
 			colors[0] = myftol(floatColor[0] * modulate);
 			colors[1] = myftol(floatColor[1] * modulate);
 			colors[2] = myftol(floatColor[2] * modulate);