Change default values of flex visualization flags.

Deactivated vertices, edges, faces and activated skins. The skin is less precise but faster to render and more importantly when the wireframe is active it allows to look inside the body much more easily.

PiperOrigin-RevId: 585970250
Change-Id: Icb6c0ff6266e552cffce9b0c810f634f9a29a55e

src/engine/engine_vis_init.c

@@ -92,10 +92,10 @@ const char* mjVISSTRING[mjNVISFLAG][3] = {
   {"S&elect Point",   "0", ""},
   {"Static Bo&dy",    "1", "D"},
   {"Skin",            "1", ";"},
-  {"Flex Vert",       "1", "."},
-  {"Flex Edge",       "1", ""},
-  {"Flex Face",       "1", ""},
-  {"Flex Skin",       "0", ""},
+  {"Flex Vert",       "0", ""},
+  {"Flex Edge",       "0", ""},
+  {"Flex Face",       "0", ""},
+  {"Flex Skin",       "1", ""},
   {"Body Tree",       "0", "`"},
   {"Flex Tree",       "0", ""},
   {"Mesh Tree",       "0", "\\"},