--- ray/src/rt/raytrace.c	2020/03/29 18:21:57	2.81
+++ ray/src/rt/raytrace.c	2021/01/04 19:07:15	2.82
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: raytrace.c,v 2.81 2020/03/29 18:21:57 greg Exp $";
+static const char RCSid[] = "$Id: raytrace.c,v 2.82 2021/01/04 19:07:15 greg Exp $";
 #endif
 /*
  *  raytrace.c - routines for tracing and shading rays.
@@ -147,6 +147,8 @@ rayclear(			/* clear a ray for (re)evaluation */
 	r->rox = NULL;
 	r->rxt = r->rmt = r->rot = FHUGE;
 	VCOPY(r->rop, r->rorg);
+	r->ron[0] = -r->rdir[0]; r->ron[1] = -r->rdir[1]; r->ron[2] = -r->rdir[2];
+	r->rod = 1.0;
 	r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
 	r->rflips = 0;
 	r->uv[0] = r->uv[1] = 0.0;