Basic vertical rendering

- Add height attribute to most particles for height generation on the fly

main.c

@@ -189,7 +189,7 @@ main(int argc, char *const *argv)
         {"help",             no_argument,       0, 'h'},
         {NULL,               no_argument,       0, 0},
     };
-
+    
     bool unlink_pid_file = false;
     const char *pid_file = NULL;