docm .3d file generation for CaveView

parsers/survex.py

@@ -31,6 +31,8 @@ todo = '''Also walk the entire tree in the :loser: repo looking for unconnected
         you will see than have the team members are recognised by this parser, but not recognised by the
         wider troggle system (the name is not a hyperlink) - apparently randomly. 
         GetPersonExpeditionNameLookup() needs to be fixed.
+        
+- fix THREEDCACHEDIR and put .3d files in same folder as .svx and fix CaveView
 '''
 survexblockroot = None
 ROOTBLOCK = "rootblock"
@@ -1161,7 +1163,9 @@ class LoadingSurvex():
 
         def runcavern():
             '''This assumes all survex files have unique names and they are taken from many folders but the output is all put 
-            into the same folder. A serius potential bug. We should check uniquness
+            into the same folder. A serious potential bug. Import parser checks uniqueness but much better not to do it like this.
+            # see design docum in troggle/templates/cave.html
+            # and views/caves.py rendercave()
             '''
             print(" -  Regenerating stale (or chaos-monkeyed) cavern .log and .3d for '{}'\n     at '{}'\n     days svx old: {:.1f}  cav:{:.1f}   log old: {:.1f}".format(fullpath, logpath, (svx_t - log_t)/(24*3600), (cav_t - log_t)/(24*3600), (now - log_t)/(24*3600)))
             #print(f'  -  cav_t: {cav_t/(24*3600)} -  log_t: {log_t/(24*3600)} -   svx_t: {svx_t/(24*3600)} -   now: {now}')