Vehicles unlinking at sim boundaries.

Has anyone else encountered this problem? I was attempting to build a vehicle this evening, and when I had the basic structure done I dropped a script for a flying carpet in it.

Two out of every three times I cross the sim boundaries I have a catastophic structural failure, and the vehicle unlinks and falls out of the sky scattering parts all over.

I have been flying along the Linden roads to avoid ban-lines and other problems. The vehicle is not being returned, it actually unlinks into a pile of parts that fall to the ground. After a few minutes the individual bits that I cannot find and delete do get returned.

Is this a giant vehicle by any chance? Maybe something in the magic carpet script? I've never had that happen...

I constantly fly in my balloon in the mainland. I've never seen such situation as you describe. I agree that it could be the script you're using. Try a different one.

It has been known to happen occasionally, but not with any real predictability.

If you can get it to do it repeatably, I am sure the Lindens would want to play with it.

I was just wondering if it was common, or something that is new to the recent patch.

The script is a pretty basic freebie that I picked up in a class last year. I edited out a bunch of extra features for particle effects, etc. I have combed through the scripts, and there is nothing in the script that would make it unlink.

There are a total of 29 prims in the vehicle. Physically the vehicle is about 20 meters long and about the same in width. All ordinary prims, no mega prims or anything unusual there.

It happened with enough regularity that I was able to demonstrate it to a friend, twice. I even tried crossing into two different sims, one to west and one to the east along the Linden road and had it happen in both places, plus at the boundaries between two other sims.

I will play with it some more and see if I can figure it out, or identify a pattern somewhere.

Me wanders off to drive her own vehicles into sim boundaries . . .

You weren't trying to get to Wally World by chance?

Just a thought: ... the 30-metre link limit is an upper maximum. However with small prims the maximum link distance can be considerably shorter. You might want to check prim sizes and link distances.

One build of mine was linkable as a single object but every time I rezzed a copy from my inventory it became a pile of unlinked prims. After alot of puzzling I discovered that the size of some prims in that build had a limiting factor on that maximum link length. The solution was to link it into several linked objects.

Obviously that solution is not an option with a physical vehicle as it has to be a single linked object. Check the prim sizes and experiment a bit.

My understanding is that "size matters".

Each sim looks 10 metres into the adjoining sims in order to deal with cross-border prims and avatars
It would not be surprising if strange things happened if a linked build that was longer than 20 metres crossed a sim boundary.
The effects should be additionally 'interesting' if the thing was moving at speed.

Due to sim and network lag, the coordination between the sim servers over a boundary would be patchy. A large-dimensioned build moving through the 10 metre zones would need lots of good karma.

Thanks for the replies. It does seem to be related to the overall size.

All of the prims are easily in normal linking distances, nothing unusual was done to make them link, and the entire vehicle is a single object.

I did try selecting the vehicle and shrinking it proportionally, and when I dropped it below about 10 meters overall in length I did not have the unlinking problem (so far at least), just the normal sim crossing lag and ejection problems I have always had when flying.

I will have to play a bit more, but it looks like if I want to maintain the scale, I may have to limit my flights to in-sim.

Does anyone know a good sim to fly in?

Also, does anyone else here play Eve-Online? What I was built was as close a replica to the Minimatar shuttle as I was able to in the 30 prim limit. I was just curious if anyone else has built one?

If it is a large prim-count vehicle, using the nonphysical movement scripts, I can repeat your problem 100%. Cross a sim line at too sharp an angle, or cross it at the corners of a sim, instant delink. Cross it at a perfect perpendicular, you only delinks on say 1 of 10 crossings. Never seen this happen on a physical, 30 prim or less vehicle (however, I have seen the entire build delink when you attempt to link a new prim to it, but that's another issue).

Its the primary reason I do not sell my Steampunk Combat airship....who wants to have to track down (or have autoreturned) 200+ prims? It'd be too big a headache dealing with your average SL user.

Yes. Sim corners. Think about it!

The prims of your vehicle are spread over four separate sims.
The sim instances are not necessarily running in the same server hardware, the same rack, same building or same state.
The sim that your avatar is in is trying to feed you information that it gets from the other 3 sims. The sim(s) that your passengers are in are doing a similar job.
If your vehicle had a mind, it would be stuck in a WTF loop.

I take my hat off to LL for even trying to make it work

Hmmm, I had something similar happen some time ago, but I just thought it was a feature. lol

I have a small airship/boat that would smash to pieces if I hit a building or "no enter" boundary. I didn't know what the heck was up, but it looked cool - bits flying everywhere if I stuck something midflight.

Heh heh, it has been ages since I flew the thing - I will try to test this again when I get home. My memory may be dim and inaccurate. Doh!

Careful with the credit rubber stamp there...

Even though an object's prims may seem to be spread across more than one sim, the object itself is only considered in the sim where the center of its root prim currently is. IE, it is only simulated by that sim. As such, ALL of its prims are still in the same simulator as the root. When it gets within the 10m border, other sims start to know about it, but do not take over the simulation of the object until the root prim crosses over into one in particular.

Delinking is a bug that happens because of really poor coding on the simulator side. It's been a known bug for years now, and isn't likely to get fixed any time soon.

Yes. On reflection the root prim "has the ball".
But the OP was really pushing the envelope of the 10 meter look-in zones with his "about 20 metres" collection of prims.

Perhaps related perhaps not but my media texture settings on a prim change when I cross regions after this release (rendering both my 2-sim video screening places unusable) - this has never happened before.

Solved mine - not related!

This problem is as mentioned before related to max link distance.
You probably built the vehicle at a straight rotation (0,90,180,270), and linked the structure in that configuration.
The link distances are calculated based on the 'global coordinate' system in a sim, NOT on the local coordinates of the root or link set. This causes an object that is completely valid when linked, to suddenly become invalid when it gets rotated.

The resulting effect is, that the object spontaneously unlinks in specific situations, where a link recalculation is triggered:
1. when a single prim is unlinked, the whole link set breaks
2. on a sim reset (although not always)
3. on sim crossings (although not always)
4. on (scripted) movement of a prim in the linkset (although sometimes the movement simply doesn't happen, instead of the whole linkset breaking)/ BTW the combination of scripted single prim positioning/movement icw a running vehicle (think sliding roofs etc.) seems to open a whole can of worms by itself. Mostly related to the same errors in link recalculation during actual movement/rotation of the whole object.

It doesn't matter if an object is phyiscal or non-physical for this to happen.

You can check if your link set is 'rotation safe', by rotating it to a random angle, and trying to unlink a single prim. (Check 'edit linked parts') If the whole structure unlinks, it's not...

IMHO This is one of the most annoying bugs in SL, although it doesn't crash sims, or cause content loss. It's a huge annoyance to constantly relink/rotate/check larger structures, to make sure they 'work' in different configurations...