nicer physicals

demos/filter.geo

@@ -459,14 +459,14 @@ Surface Loop(6031) = {184,6020,6030,6028,6018,-6024,-6022,-6026};
 //Complex Volume(6032) = {6031};
 
 
-AIR = 10000 ;
-R1 = 20000 ;
-R2 = 30000 ;
-TT1 = 40000 ;
-TT2 = 50000 ;
-CLD0 = 60000 ;
-SOU  = 70000 ;
-CLTEM  = 80000 ;
+AIR = 1 ;
+R1 = 2 ;
+R2 = 3 ;
+TT1 = 4 ;
+TT2 = 5 ;
+CLD0 = 6 ;
+SOU  = 7 ;
+CLTEM  = 8 ;
 
 Physical Volume  (AIR)     = 6002;