Waste Disposal - bug with Rumblers

[Amrynel]

Hi, I noticed on Waste Disposal that Rumblers will sometimes make a right turn at the first grid area - straight through my defensive line of towers. Here's an example setup I've seen affected:


<code>

..OO.

CCTCC

.OOO. <--- incoming path of Rumbler ---
</code>



Where 'O' is an unused square, 'C' is a cannon and 'T' is a temporal.

One other datum that might be important is that so far I've only had it happen when using fast forward. I suggest fast forwarding through Wave 19 on Practice Mode a few times, it happens maybe 1 in 4?

[Amrynel]

I've also, once in a while, seen a Rumbler go straight through the "blue pulse" of a Temporal without being affected. I can't reproduce it though, so it might be an optical illusion or something.

[kofrad]

To me it seems likely to be one of those 'freak accidents' that occur in programming. During development it can be next to impossible to check every single piece of information for errors. Sounds like something slipped through the cracks.

[jeff]

So, likely the reason the rumbler is going through the cannon tower is that its path is blocked somewhere else.* The way the AI logic works is that if there is an open path it will take it, but if there is not, it will take the shortest path through the least number of towers.





The information above is saying which path the rumbler took (which is the shortest path, it turns to the right immediately), but it doesn't have the info of where you have a way out so we can't know if the rumbler should have turned or not.





As for temporal towers, when there is only one temporal tower, fast aliens such as racers or rumblers can actually make it past the tower fast enough that they get by in between pulses - it doesn't always happen, but it can happen.* Upgrading the tower or having two temporal towers nearby can prevent this.





Jeff

[Amrynel]

Sorry Jeff. I shall be clear: all aliens follow the unblocked path, except for the rumbler which occasionally turns and goes through the line of towers if I am fast forwarding on Waste Disposal. If the bug does not occur, then backspacing and fast forwarding again, without making any changes to my defense grid, can reproduce the bug. It does not happen every time, but it will happen every N times where N is (so far) smaller than five. If you are having trouble reproducing this bug, I can record a video of it.

[jeff]

A video of the bug would be great!* Thanks much.





Jeff

[Amrynel]

The raw file got extremely choppy just when the bug occurred, and after editing I had a 54MB MPEG4 file. So I think I'll have another go. With that in mind, how do you want the video? (e.g. emailed or uploaded or other, codec used, resolution, time period captured, file size, etc)

[Amrynel]

Now have a 2.42MB xvid clip, 840x524@25fps. Shows a Rumber doing a right turn between a tower and a cliff face. Have also seen Rumblers do right turns between two Cannons, between a Cannon and a Temporal, etc.

[jeff]

You can post it to Youtube if you'd like, or email it if it is under 5MB.





Jeff

[floridabroncos]

I noticed this bug in Grinder Mode on this map. I made sure that there was a clear path for the AI to follow, but on just about every run, at least one walker would make an immediate right turn. I didn't catch it until I had been following the action away from the beginning and then suddenly, without warning, I saw that two orbs were taken. "Impossible!" I said, seeing as how I had been keeping up with the walkers and not one had gotten through all my defenses yet. So I started watching them from the very beginning, and sure enough, on just about every run one or two of the walkers would take an immediate right turn, despite the way being blocked and another path being open to the orbs.

[jeff]

Usually this bug appears when a user has very low frame rate and the timing gets off in the AI for the fastest aliens - typically rumblers.





Jeff

[euphoria]

Loads of pathing errors on the Badlands Xbox version of this. All have the same symptoms, clear paths available but instead of following them certain units will opt to go straight through towers, lost a couple of games cos of the bugs. Not sure why I have only noticed it on the badlands levels and not the awakening though....curious...