[Pogamut-list] 3.3.0 Upgrade Issues

[michal.bida]

Re: 3.3.0 Upgrade Issues

Author: michal.bida

I've completely overlooked this thread, sorry. 

1) isReachable attribute is really gone. Computing reachability of all thing the bot could see was very expensive and caused server to lag when more bots were connected. Moreover we agreed that usability of this information is not very high - always there exist path towards thing you see if you use navigation graph and running somewhere straight is usually not a good idea anyway (even if something was reachable, it could mean the bot needed to do at least one jump to reach the destination, but there was no way how to find out if it is the case). Can you describe the scenario where you have been using isReachable attribute previously? 
The check reachability command returns the same info isReachable attirubte did, but now you need to send this request manually and wait for the answer (you get a message back with the same id you have issued. You also need to input id of the object you want to find if it is reachable or not.) The whole reachability thing in UT has issues, if the object will be further than 1000 ut units, the reachable will always return false, even if there is straight way towards it (that's another reason for us to remove it).
The easiest replacement of isReachable (and better I think) is something like - i want to know the reachability of object A - first step - find closest navpoint to A, second step, find path with floydwarshall map towards A, step three - examine the path I have gotten - does ti "go around" (not very straight) - this means the point probably is not reachable, does it go more or less straight? - this could mean I can reach it directly, does it go more or less straight, but there are tricky navpoints and edges (e.g. jump spots, jump points, etc) - this means the point could be reachable, but I should be careful.

2) FloydWarshall path planner indeed is fully functional and we are using it ourselves in all of our examples. How it works - in the handshake when the bot receives info about nav points, FW planner computes all the paths in advance (on the biggest maps it can take tens of seconds, on normal maps its instant). This means that when the bot is spawned you can use FW planner to compute any path instantly (it responds even faster then UT A* - you don't need to wait for the response from UT server ). You don't need any locks, the FW should be finished by the time botFirstSpawn method is called (Is that right Jakub? :-) ). Well so far I hadn't any issues with FW planner concerning this, so I am pretty confident it is the case. :-) 
Also we have used FW planner in our lectures half a year now and everything was smooth...

Best,
Michal

-- 
Reply Link: <http://diana.ms.mff.cuni.cz/main/tiki-view_forum_thread.php?forumId=4&comments_reply_threadId=4&comments_parentId=956&post_reply=1#form>