Topic: D3 Level 4 thief bug

[NUMBERZero]

Yay! First post in this area too!

This pilot seems to have a bit of a thief problem. Any idea what's going on?

[TechPro]

I think he's got a defective save position.

If he worked through the levels again (fresh) ... I'll bet it doesn't happen to him a second time.

Unfortunately, I doubt he wanted to hear that.  Hope he's got a saved spot from earlier in the level run.  That would save some time.

So how did this happen?   I think (repeat, think/guess/suppose) that he happened to be at the same spot the thief "appears" from time to time, or he and the thief happened to get "merged" (two objects bumped together just right allowing their object vertices to get hung up on each other).  It can happen.  You know that level where you hit a switch to reverse a fan, then enter the passage and the wind pushes you to the top of the passage where you can release a big rotating thing (heat sink?) that then drops down and destroys the fan on impact ... sometimes the guidebot gets "snagged" in that thing and ends up riding it down to the fan.   Perhaps the same thing happened with this guy's pyro and the thief.

[NUMBERZero]

Actually in a comment on another video that led to me finding this stated that he get's through the subway and it starts happening. Darc said in the IRC that it happens when a robot is outside of the level. He does it with the GB all of the time. I think I fully understand how that would work or how he is able to do that (MD it into the sky and duck behind a building so that is supposed to hit a wall?).

A simple explanation in my book would be that the thief is in another dimension and can attack you, but you can't.

[Scyphi]

I think I'm with NumberZero on this one, as that's the only feasible explanation for it all, and it would explain why the thief seems to be "out of phase". If he were attached to the ship, you'd be constantly seeing him, hearing him, and probably be constantly taking damage as the game would more than likely consider it hit damage from bumping into each other. Instead, the video shows the thief appearing, and then vanishing again, like he just comes and goes.

What I don't get is how the thief could've gotten "outside" the level. I mean, I know the level isn't perfect in construction (we've all found plenty of flaws with it) but this is the first time I've ever heard of this happening, and I somehow doubt a robot of any AI level could've managed it on it's own.

Hmm...

I imagine a fresh restart of the level should fix it, as TechPro suggested. If not, then maybe there's something wrong with the game itself, but I'd somehow doubt it.

You do have to admit that it IS kind of cool, seeing a phantom thief flying around and attacking you.

[-<WillyP>-]

I don't think 'outside the level' is the answer. I have placed bots outside the level, and the level 'Deadly Maze' has hundreds of bots placed outside the level. Neither exhibited this phenomenon. Also, 'MD'ing a bot into the sky' would not put a bot out of the level.

I think... er, guess,   the memory registers became out of sync and the game was using the player's position marker for the Thief. There would be no damage as the Thief is not actually colliding with the player, just like someone riding in your car. It's a random anomaly, probably not happen again once the level is restarted, but if it does perhaps re-booting the machine would. If it still persists, I would re-install D3.

[NUMBERZero]

It didn't happen just once. Multiple times. I guess it's his D3.

[-<WillyP>-]

Or maybe his video card drivers, or memory. 

[Foil]

No, it's not a problem with his D3 or drivers, etc.

It's exactly what was suggested above, that the thief-bot got out of the level shell (possibly through the subway, or another hole in the shell somewhere).

You have to understand that D3 is highly room-based, and every object in the game has a room-flag that D3 uses to determine what to display, etc. 

The problem occurs when an object doesn't travel from room to room through the normal portal faces, so the room-flag doesn't get updated properly.  This of course happens when an object is outside the level shell. 

Now, when an object's location is in a room, but its room-flag is pointing to another room, strange things can happen.  Sometimes objects (or rooms, if you're the one flying outside the shell) don't get rendered.  Sometimes it causes a crash (if you fly back into that room through a portal).  Sometimes weapon collision-detections don't work right.  And other weird stuff.

How do I know this?  I dealt with teleport-crashes and other odd behavior because of room flags when I built the BreakOut mod. 

[-<WillyP>-]

Ok, but that doesn't explain how the thief bot could appear at the same location as the player.

[Foil]

Ok, but that doesn't explain how the thief bot could appear at the same location as the player.

Precisely the same reason.  The thief was essentially flying through him without any 'bumps' because collision detection doesn't work for objects with different room-flags.  He only saw glimpses of the thief when the thief was essentially on top of him.

[-<WillyP>-]

I suppose that makes some sense.

Now, what about placing bots outside a level, I've done it, so have others... the only effect I've noticed is that the bot in question could travel thru walls, in both directions.

The first level I made, I placed a Tubbs outside the level. He'd come and give me a whack or two then just casually wander off, completely disregarding any wall that happened to be in his way. It was pretty spooky, I'll tell you!

[Foil]

Interesting!  I wonder if that leaves the bot untied to any room... hmm.

[Ronin RedFox]

If that is true, you could make some cool levels with that 

[NUMBERZero]

XD you wouldn't believe what happened on Lv 14 today! The same thing with the thief! Only better! With a frickin' Sharc! Got it on video too. I could never see it. I accelerated and flew around the clock room faster than it can when it is "in phase" and it still ate me. At least when I died, I took the bugger with me.

I guess it sort of just disappeared. It got behind be out of view and it started. I think it was beginning to fly through walls before too. I was getting around 15 FPS (thanks to CRAPS) if that had anything to do with it.

[Scyphi]

If that is true, you could make some cool levels with that.

Concurred, a possible Halloween-themed level, perhaps?

Of course, purposely exploiting a bug could potentially lead to more bugs.

And to answer WillyP's question, I think I know why you got different results with your Tubbs. I'm thinking that because you purposely placed them outside the level when building it, that's where they started from and lacked, as Foil suggested, the right flags to produce it.

Our phantom thief, however, was bound to have started in an actual room that he was assigned to, all of which D3 knew and kept track of. The moment the thief got 'outside' the level, it sent D3 into a fit as the thief was in one spot, but it's records suggested otherwise and had conflicting data. It tried to make do, and viola! We have a phantom thief.

At least, that's how I'm guessing it worked, and that's presuming I understood entirely what Foil said about portals and flags and the such. Feel free to correct me if so need be.