--- ray/src/rt/rtmain.c	2023/08/15 00:46:56	2.45
+++ ray/src/rt/rtmain.c	2023/08/15 01:19:37	2.46
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: rtmain.c,v 2.45 2023/08/15 00:46:56 greg Exp $";
+static const char	RCSid[] = "$Id: rtmain.c,v 2.46 2023/08/15 01:19:37 greg Exp $";
 #endif
 /*
  *  rtmain.c - main for rtrace per-ray calculation program
@@ -68,12 +68,14 @@ static void printdefaults(void);
 #ifdef PERSIST
 #define RTRACE_FEATURES	"Persist\nParallelPersist\nMultiprocessing\n" \
 			"IrradianceCalc\nImmediateIrradiance\nDistanceLimiting\n" \
+			"ParticipatingMedia=Mist\n" \
 			"HessianAmbientCache\nAmbientAveraging\n" \
 			"AmbientValueSharing\nAdaptiveShadowTesting\n" \
 			"InputFormats=a,f,d\nOutputFormats=a,f,d,c\n" \
 			"Outputs=o,d,v,V,w,W,l,L,c,p,n,N,s,m,M,r,x,R,X,~\n"
 #else
 #define RTRACE_FEATURES	"IrradianceCalc\nIrradianceCalc\nDistanceLimiting\n" \
+			"ParticipatingMedia=Mist\n" \
 			"HessianAmbientCache\nAmbientAveraging\n" \
 			"AmbientValueSharing\nAdaptiveShadowTesting\n" \
 			"InputFormats=a,f,d\nOutputFormats=a,f,d,c\n" \