Ships with subentities and collision detection bug fixed

Post by **Eric Walch** » Sun Aug 16, 2009 9:05 pm

But on a completely other subject:

Another Commander, with rev 2290 you cracked it, that long standing bug. After reading your comment I immediately went for a buoy repair station and flew 5 times though the arch. Without crash.

That station has also a few inspection ships. I had programmed a complex route in the past to follow. e.g. below the arch, around the ship. Until now those controllers always crashed somewhere without any visible contact. I never witnessed one completing his tour. So those routes never made it in the release version. In release the ships only fly a route far outside the main bounding box.
I activated that old, close by, route around the station. Until now without crash. At least not in the part that was tested.

I'll test a bit further as this station asks the most of collision detection of what I know.

Post by **Kaks** » Sun Aug 16, 2009 9:41 pm

Just wanted to agree with Eric, it looks very much like ships with subentities can safely refuel at Thargoid's petrol stations now! Thank you, A_C!

Wiki pages · Post by **Thargoid** » Mon Aug 17, 2009 7:19 am

Yay, profits soar poet!

goran · Post by **goran** » Mon Aug 17, 2009 9:15 am

Kaks wrote:
Just wanted to agree with Eric, it looks very much like ships with subentities can safely refuel at Thargoid's petrol stations now! Thank you, A_C!

Yiiihaaaaa!

Lestradae · Post by **Lestradae** » Mon Aug 17, 2009 9:17 am

@Squashed turret/subent-bug: Go, A_C, go!

L

Website · Post by **DaddyHoggy** » Mon Aug 17, 2009 9:45 am

So, what was the bug? Dodgy orientation?

Post by **Eric Walch** » Mon Aug 17, 2009 9:58 am

DaddyHoggy wrote:
So, what was the bug? Dodgy orientation?

Something very trivial as it seems when this was really the bug. Mixing up of ownership when I read A_C his fix correctly. Not the thing you look for when examining collisions. But most bugs look trivial in hindsight.

Post by **another_commander** » Mon Aug 17, 2009 10:01 am

DaddyHoggy wrote:
So, what was the bug? Dodgy orientation?

You won't believe it, but apparently it was yet another copy/paste error that was there since 1.71. In the -doOctreesCollide: method inside ShipEntity.m, there were these lines:

Code: Select all

Vector		other_position = [prime absolutePositionForSubentity];
Triangle	other_ijk = [prime absoluteIJKForSubentity];
Vector		prime_position = [other absolutePositionForSubentity];
Triangle	prime_ijk = [other absoluteIJKForSubentity];

See the problem? Because of prime_position and other_position as well as prime_ijk and other_ijk basically being cross-referenced, the octree collision detection was going south pretty fast since the octree positions being compared were completely off. The funniest part is that it seemed to generally work unless you had subentities on your object, but it was broken for at least two releases.

Also, split to its own thread.

goran · Post by **goran** » Mon Aug 17, 2009 10:34 am

I just died inside the Fuel station.

Got inside, dead stop, fuel transfer started, happy grin on my face and then BOOOOM! You're dead, press space commander...

Will try again...

Post by **another_commander** » Mon Aug 17, 2009 10:35 am

Please send the log from that gameover before it gets overwritten!

goran · Post by **goran** » Mon Aug 17, 2009 10:39 am

If You think about latest.log, there is nothing in there about the death...

I'll try again now...

It worked!

False alarm, everybody proceed with their regular duties...

Post by **Eric Walch** » Tue Aug 18, 2009 3:38 pm

I have been examining the big dockers at the GRS station. For some reason their collision worsened. Normally 1 out of 3 crashed while docking (has never been perfect). With the fixed collision most big ships collided on entry of the docks. Probably that was collision detection as it always should happened. Trying to fix the collision in the past I already let the ships enter de docks along a path, 40 meter below the centre because the docks are open on that side. I just raised that value to 60 meter below the centre and now most ships survived until now. Only witnessed two crashes, what is better than before.

There were some other issues with the AI, but now big NPC ships dock fine with me on the external docks. Current release of buoyRepair will show more crashes with 1.73 than with 1.72.

goran · Post by **goran** » Wed Aug 19, 2009 9:33 am

During the last refueling at Fuel Station, i noticed the blip on the scanner that is getting closer and closer. Switch to rear view revealed a Phoenix entering the Station disregarding me being in there already. I had to leave before blind #$!# push me into the station walls. Maybe something like that caused my first refueling death...

Website · Post by **DaddyHoggy** » Wed Aug 19, 2009 10:01 am

gorans wrote:
During the last refueling at Fuel Station, i noticed the blip on the scanner that is getting closer and closer. Switch to rear view revealed a Phoenix entering the Station disregarding me being in there already. I had to leave before blind #$!# push me into the station walls. Maybe something like that caused my first refueling death...

Perhaps it was driven/flown by the same 'white-van-man' who blocked me in at the fuel pump when I was filling up this morning (he was behind me and when the pump ahead of me became clear he drove round me and left his van parked at an angle to the pump while he went off to get a paper from the kiosk...). Too many cars for me to reverse up so I was very grown up about it and left my hand on the horn until he came back out - he glared at me but got back in and drove off without fuelling up!

However, back to Oolite, this sounds like a little AI tweaking is required - if ship already refuelling do not enter ring!

Wiki pages · Post by **Thargoid** » Wed Aug 19, 2009 10:09 am

I'm not sure quite how easy that will actually be to do.

The current NPC ship AI (and indeed the whole NPC use of fuel stations) is Eric's update to my original, and from my neophyte AI skills it would be a less than trivial issue to detect when the station actually has a ship inside it before the AI tells the NPC ship to go in itself.