Teleport Without Error problem

[OrlonKronsteen]

Hi DavidW, I see you are back and planning another round of SCS. Thank you, as always!

There is a big problem with the Teleport Without Error ability used by fiends - and possibly some other creatures. You have probably heard of this already (I think it's been mentioned before), but in case you can't remember all of the myriad reports you've been getting on the SCS thread, I thought I'd bring it up again, as it's a dreadful bug.

Basically, what happens is the demon (in my experience it's the chromatic demon on level 2 of Watcher's Keep) will teleport on top of one of your characters, who get stuck in their circle. Reports vary, but in my experience the demon basically teleports over and over, chasing my weaker characters, like Jan, Viccy, or my sorcerer, around the room. Unlike in some other reports, being in or out of visual range has had no bearing on this for me. Now, according to info in this thread, from the Beamdog Forums, the problem originates with pathfinding in the EEs, and was introduced after one of the patches, so it's not something introduced by SCS. I don't know if this is something you can fix (I suspect it might be one of those hard-coded IE issues), but, if not, I was wondering if you could give us the ability to disable the TWE ability (through the ini, console, or some other means). I'd rather not have that feature than to be constantly using control-j to free my characters.

Anyway, thanks as always for your hard work, generosity, and infinite patience.

[DavidW]

Thanks, will take a look. How easy is it to reproduce - does it happen all the time?

[OrlonKronsteen]

AFAIK it should be easy to reproduce, as I've seen several players mention it in different threads - including the one I linked to. In that thread, it's mentioned that it happens with Amelyssan and Draconis, as well as the chromatic demon. I'm not sure if there are more enemies than that.

As for my experience, it happens every time I fight the chromatic demon. Admittedly, since I play no reloads now and I'm not that good, that isn't too often. But at least four or five times, I'd say.

I'm sorry I don't have a save to share. The only mods I use are Tweaks Anthology and SCS, so that should rule out an abundance of detective work. I'm inclined to agree that it's probably related to EE pathfinding, as your characters can get stuck together in tight spaces. I think that started with 2.5.

[polytope]

Getting trapped "under" creatures with big selection areas can definitely happen on the original engine but seems more common with EE from all reports, along with possibly related pathfinding problems, it's evidently an engine level problem in any case which means there's unlikely to be a clean fix forthcoming from the community soon.

Old school way of preventing this bug, rather than teleporting directly to the character, the creature with teleport abilities spawns an undetectably invisible small creature which is scripted to stick close to the least protected character in sight (high movement rate) switching from MoveToObject() over to RandomWalkContinuous() when within a range of about 4, this little guy acts as nothing but the target for larger teleporters.

Unfortunately this is not suitable when there are multiple large creatures trying to teleport in an area, gated balors for instance. A possible solution is to rework the teleporting so that the creature:

1. Polymorphs into a smaller form like bat
2. Gains unbreakable invisibility, untargetable, damage immune, high movement rate
3. Flips back to normal when within a certain range of whoever they were moving toward

As I said, unlikely to be a clean solution in the immediate future.

[DavidW]

Annoyingly, I haven't been able to replicate this, despite numerous attempts. I'm sure it's happening, but without a test case it's very hard to test attempted fixes.

[OrlonKronsteen]

Thanks for looking, David. If/when I run into it again, I'll attach a save, if you think that would be helpful.

[polytope]

Perhaps monsters with larger "personal space" than the default humanoid (like Balors) shouldn't get Teleport Without Error but instead just a version of Telekinesis that doesn't have a save (call it Irresistible Pull or something along those lines?) and drags the target toward them. Opcode #274 for phasing might be less bugged than teleporting, but it doesn't allow targeting of a specific PC.

Otherwise I can only reiterate my earlier suggestion to fake the teleport spell by breaking it down into a sequence of more reliable scripted actions:

Quote

1. Polymorphs into a smaller form like bat
2. Gains unbreakable invisibility, untargetable, damage immune, high movement rate
3. Flips back to normal when within a certain range of whoever they were moving toward

Although actually I'm not sure if polymorphing to and from a smaller creature won't also trigger the bug in some circumstances, as I said, larger animations probably should get some substitute like a better Telekinesis.

If you're trying to replicate the bug I'd test it in an area with lots of thin corridors, like the planar prison accessible in Haer's quest.

[DavidW]

I’ve tried in that area for twenty minutes and got nowhere. Since it’s an engine issue it could even depend on install details.

Without being able to replicate the bug, I can’t really test possible solutions. I think the best I can do for now is add a console override to turn off teleportation in places where players are running into trouble.