added variations to sand rubble and cave-wall.

data/terrain-graphics.cfg

@@ -353,7 +353,9 @@
 {SHEX_LAYER *^Gvs      farm       -10       50      flat/farm-veg-spring2}
 {SHEX_LAYER *^Gvs      farm       -10       100     flat/farm-veg-spring3}
 
-{SHEX 		*^Dr       overlay              100     sand_rubble}
+{SHEX 		*^Dr       overlay              33      sand_rubble1}
+{SHEX 		*^Dr       overlay              50      sand_rubble2}
+{SHEX 		*^Dr       overlay              100     sand_rubble3}
 
 
 
@@ -367,7 +369,9 @@
 {TERRAIN_BASE_PROB  Uu                  cave/floor5		       50}
 {TERRAIN_BASE       Uu                  cave/floor6}
 
-{TERRAIN_BASE       Xu                  cave/wall-rough}
+{TERRAIN_BASE_PROB  Xu                  cave/wall-rough1       33}
+{TERRAIN_BASE_PROB  Xu                  cave/wall-rough2       50}
+{TERRAIN_BASE       Xu                  cave/wall-rough3}
 
 #33% 33% 33%
 {TERRAIN_BASE_PROB  Uh                  cave/hills-variation1    33}

data/terrain.cfg

@@ -987,7 +987,7 @@ editor_group=rough
 [/terrain]
 
 [terrain]
-symbol_image=cave/wall-rough
+symbol_image=cave/wall-rough1
 id=cavewall
 name= _ "Cave Wall"
 string=Xu