--- ray/src/common/fvect.h	1992/10/02 15:54:57	2.4
+++ ray/src/common/fvect.h	1997/10/22 14:15:47	2.5
@@ -15,6 +15,7 @@ typedef FLOAT  FVECT[3];
 
 #define  VCOPY(v1,v2)	((v1)[0]=(v2)[0],(v1)[1]=(v2)[1],(v1)[2]=(v2)[2])
 #define  DOT(v1,v2)	((v1)[0]*(v2)[0]+(v1)[1]*(v2)[1]+(v1)[2]*(v2)[2])
+#define  VLEN(v)	sqrt(DOT(v,v))
 #define  VSUM(vr,v1,v2,f)	((vr)[0]=(v1)[0]+(f)*(v2)[0], \
 				(vr)[1]=(v1)[1]+(f)*(v2)[1], \
 				(vr)[2]=(v1)[2]+(f)*(v2)[2])