Region Crossing: A Report On Experience.

[WolfBaginski Bearsfoot]

With the threaded code now running on all regions, we can now properly see what it does. Over the last weekend, which is never a good time, I've managed to make some lengthy journeys over the Grid. Some aspects have improved, some things are different.

1: The quality of region crossings is not the best I have seen. I infer, from past efforts, their results, and those improvements eroding as time passed, that the distance between servers on the LL network still has significant effect. The reduction of three co-locations to two has made things significantly worse.

2: For vehicles, the new Threaded Code has made the best crossings a little worse, but crossings that would once have failed are now, eventually, completed. Wait long enough, and the wild uncontrolled rides will end in a jump back to a stable state in roughly the intended place. But there are more crossings that show brief glitches.

3: Foot crossings seem to be about the same as they were.

 4: We're told that the big effect of the threaded code is on other users. It means the sim doesn't stall while handling a crossing. I wouldn't be surprised if this is why the wild rides can eventually end without crashing. But I cannot easily test this. I'd expect to see signs of this improving to be visible to the sailing community, whose races involve multiple region crossings. A bunch of AVs in vehicle will cross the boundary, with observers on both sides.

5: The old bugs are still there, such as the parcel-full problem for vehicles when they cross a region boundary. Vehicles in a region should be using a separate pool of prims, so they don't crash out with full-parcel errors, but there has always been something about the region-crossing process that breaks this. And the typical camera position for driving a vehicle is still bad for detecting ban-lines before you hit them. These effects, and occasional no-warning security orbs, have been the primary cause of disrupted journeys in my tests.

6: Before the threaded code rolled out, the best I ever did was a trip of about 50 region crossings, usually ending in the vehicle vanishing and being dumped at (0,0,0) with the AV in an uncontrollable state. Often a logout was the only cure. The new system seems to make 80 crossings attainable, and the main cause of problems are those listed in para 5. There is room for improvement, and there may be some effects attributable to particular RC code which leads to lag. Magnum is a bit dodgy, and I have a vague unease about the Le Tigre code. Anything which slows down the process lag in a server or a sluggish network, is still going to be a problem.

Thanks, guys. There's still work to do, but the new code is a big improvement.

[Orca Flotta]

Thx Wolf, with your friendly permission I'll reblog your post in my blog and on the SL sailing forum.

I find that crossings have become worse, but that's not empirical data, just subjective observation. Also I often find myself in the corner of a sim although I crossed the border more midsim. That's not reliable behaviour you need for example in races.

Are vehicle users in SL such an insignificant minority that LL can get away with such unpredictable stuff? Seems after 10 years of existence they stil haven't figured out what the customers want.

[Malate Banufong]

Thanks Wolf for writing up your experiences and observations, all of which I agree with and have experienced. I would just add that I now find mesh planes (vehicles) to be less good at SIM crossings than traditional planes. Are you finding the same ?

[Knowl Paine]

I don't know anything about servers.

Asking why Regions are square; didn't go anywhere last time I asked. If LL could redefine the shape of a Region, subdivided land could run on a separate server.  

Teleporting to a beta grid, upon entering a roadway, might be a bit too much.

Tell the server to move the car under the patch, and to mirror it on the road? idk.

 

If they moved Zindra, they can depopulate a few Regions, where it's feasible. Some Regions with roads are too heavily built, and will always have Residents.

 For the regions that can be reclaimed by LL, the LDPW could rebuild those roads in mesh, adjust the terrain to compliment the adjacent Regions, open up the Roads, add a few trees (don't go nuts), create some side lots to park.

 

 

 

 

 

[Ina Fairport]

I sail in SL for 5 years now and region crossing has always been a problem. Sometimes it gets better but a few weeks later on its horrible again.
I get the idea that LL can't resolve this problem or simply don't want to resolve it. And when they say this is their highest priority I don't believe it anymore.

I quit flying in SL because of the simcrossing problem. Flying in SL has become a silly game because of all the crashes.

And did you ever try to explore the old roads of mainland by car or motorbike ?? That is absolutely no fun at all..(
I know mainland roads where even a slow horsride trip is an hazardous adventure.

I stick to sailing and prefer the private estates and blake sea. Sailing on mainland is most of the time horrible...

[WolfBaginski Bearsfoot]

Sure, go ahead and re-publish.

[WolfBaginski Bearsfoot]

I have no idea why my paragraphs have run together.

[WolfBaginski Bearsfoot]

It is possible that Mesh is a bigger load, more work for the region-crossing process, more data to be sent from one sim to the next. And good scripts beat bad scripts. I suspect Mesh can be part of a problem. Go to the right source, and you will get a good vehicle.

With the changes in the Physics engines over the years, I'd be wary of old freebies. Cubey Terra made a good submarine and that script has been re-used by many, but some constants set in the program need adjusting. Ground vehicles can be tricky since the Pathfinding-linked changes. I kniw who I have had good results from, but I haven't tried every vehicle out there.

Anyone reading this who makes and sells vehicles? Think about updating the scripts on some of your older vehicles.

 

[Triple Peccable]

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WolfBaginski Bearsfoot wrote:

5: The old bugs are still there, such as the parcel-full problem for vehicles when they cross a region boundary.

 

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Can you point to a specific place where this is still a problem? I have done a lot of testing, and from what I can tell that problem is fixed. It has been replaced with a new problem: Crossing into or out of a private parcel while crossing a sim boundry.

I was so sure the full parcel problem was fixed that I removed that check from the Ban Line HUD, and replaced it with private parcel detection.

 

[WolfBaginski Bearsfoot]

I was down in the Snowlands... I think it was the SW corner of Eagan region, which looks like a really bad arrangement of road and sim boundaries anyway. Uzume to Kuula was dodgy a few weeks ago, partly one of those spikes of land the Lindens sold.

 

[Sigren Panthar]

Unhtil now, I have only crossed the sims I like to explore in a small warbug airplane.  There is usually a slight stutter, and then I am through flying in next sim.

Naturally, I assumed from this experience that all these tales of bad sim crossings in vehicles were from people with low spec PC's and/or bad connections etc.

Until that is, I decided to tour some mainland roads on my motorcycle.

I can only describe it as a nightmare.   When going across the sim edge, every time I would find myself tumbling into the ground in slow motion or flying way up in the sky, for a good 10-15 seconds.   

Any new person coming to SL from some of the modern gaming websites would most probably not come back.

Clearly, for reasons I am to tech ignorant to perceive, this is a difficult technical problem for LL to solve.

But. That does not alter the fact that a) they need to solve it and b) should have solved it if - as seems to be the case - this problem has been around for some time.

[WolfBaginski Bearsfoot]

I canfirm that I get hit by Parcel Full travelling on the Linden road from Kuula to Uzume, left side of the road, where the road prims overlap a non-Kinden parcel. Travelling in the opposite direction isn't a problem, it seems to be the combination of Region Crossing and Full Parcel that does it.

Kuula can be a bit busy, with the NCI site. NCI has a big rez zone between the castle and Uli region. There's a small one on the road to the west, at the T-junction by the bridge in Koleamoku region.

 

[dd Temin]

I have been creating/flying aircraft in SL for the past 6 years.

I use a high spec gaming pc with I7 processor , Nvidia dedicated  graphics, and 20 mb connection speed,

Sim border cossings in vehicles has been bad fo all 6 years in spite of all the attempts to Fix this issue, it remains as bad if not worse than ever for vehicles.

There has been great improvment in avatar only sim boarder crossing....but vehicle crossings remain barely useable.

If an  aircraft crosses the sim boundry  .... directly perpendicular to the  sim boundry   and away from corners  and keeps the speed of the aicraft low to moderate velocity.........there is only a short time/distance  "loss of control".

As the  velocity of the aircraft increases this distance of  "control loss" increases until   the aircraft  has flown completly across the entire sim...at which  point the aircraft flies into la la land  and usually crashes the viewer  ,    crash into the ground, or ends up at the bottom of the ocean.    Remember this is the best case situation where the aircraft enters the next sim perpendicular to the sim border.

If the aircraft is in  a bank  or turn as it crosses the boarder..."loss of control"  last  much longer  even at moderate speeds....and viewer crashes are  more likely to occur.

The sim server software is simply incapable of doing vehicle "hand over" to the next sim at  a speed fast enough to have  neglible "loss of control" time..

There is only one solution that I know of ...to solve this problem.  MEGA REGIONS

We need several  large PUBLIC  MEGA SIM Estates designated for Flying or Sailing consisting of a 25 sim grids(5 by 5)

We also need the OPTION  of creating private island Mega Sims consisting of either 4,9,16,or 25 sims.

This is quite easy to implement with existing Sim server software.

On Open sim.......(os grid ) I  currently run  a  4 sim Mega region myself   and my friend  Alecia  has a 25 sim mega region.........To do this....you only need to change one line in the Open Sim initialization to TRUE    (its FALSE by default).

There is no reason why  the Lindens could not offer this in  Second Life as well.

Of coures the private island mega region would need to have 1 owner....or owner group. It  would be similar to a "homestead" type of private island sim.   in order to keep the monthly tier to a reasonable level.
:matte-motes-sunglasses-3:

 

 

[dd Temin]

PS...For those who dont know what MEGA SIM is.....:

A mega Sim consist of 4,9 16 or 25 sims in a grid  "joined " into ONE  big region  with NO Sim Crossings.

:matte-motes-sunglasses-3:

[161488303349]

my experience is that the new code is marginally better for vehicles

when both sims are functioning normally then the handoff is pretty smooth. I am on ADSL2 copperwire 8.0Mbps down  and 0.8Mbps up theoretical (800kbps) and my ping to USA is typical 250-300. so pretty slow

+

when the sims are lagging (server load not network) then the handoff will eventually resolve if the vehicle don't run away and hit the 511 barrier before the handoff is complete

511 barrier being the far side of the sim beyond the sim you entering. depending on direction: 511 can be 511, -511 x or y. -1 or 257 xy is another kinda error and I not deal with that here this time

+ 

bc the vehicle is under propulsion the 511 can happen often. if you hit the 511 barrier then you get visually stuck onscreen until the sims catch up. but the vehicle keeps moving with you on it. and if you keep pressing the drive arrow keys then it will keep moving even further and further

stuck meaning your camera is with your onscreen representation which has stopped.  and anything/anyone that comes within the view of your stuck position you can see. they cant see you tho bc you are somewhere else in world on your vehicle and anyone in that area of the grid can see it/you

+

the interesting thing is that if you log in your alt at same time. can send them a Teleport and they will come to where you are actual are in world. not to where your stuck camera is. they can see you at that position. not at the position that you think you are stuck.

if alt goes to the stuck position. they cant see you there bc you in the other place. but you can see them

+

 

if you alt sit on the vehicle in its real position. then you can drive the vehicle from your stuck position using your alt camera with you both sitting on it. when the vehicle crosses the next border then your main camera will snap to the true position which by then can be 3 or more even sims away

something about the alt or any other person sitting on the vehicle while in this state triggers some kinda reset in the vehicle camera setup seems like when the sim change happens and both viewers get updated

+

sure sims lag serverside and can even insta-crash you sometimes. the -1 problem which am sure is defo serverside and/or network lag timeout

but the 511 is a clientside effect seems like. so maybe linden can look it from that pov. bc when it happens we think we have crashed. but we haven't. not server side anyways. we still inworld and moving normally. we just cant see it happening. and so we have to relog

 

  

[WolfBaginski Bearsfoot]

I don't see any obvious reasons why such a mega-sim, or several in a group, couldn't be on LL servers and TP-connected to the rest of the Grid. I wouldn't be surprised if the server code is different enough from the OpenSim code that it isn't a practical option.

I would suggest as a starting point for such a project those Premium Sandbox regions.

Since there is a problem for region-crossing if the regions involved are different sizes, TP-only is the way to go. I can't see the Pirate Battle area of the Blake Sea becoming a 2x2 Mega Region, but I remember a group of pirate-themed private islands from my early days, and such a place is another obvious candidate.

I think that a more likely answer will be a growth in the use of Micro/Petite AVs, and vehicles scaled to suit.

[WolfBaginski Bearsfoot]

That has been a common failure mode for as far back as I can recall.

I think there's a bit more stutter, maybe a region crossing process taking several time-slices to complete (is that the right term) instead of locking up the servers until the process completes. The new method doesn't halt so easily. so there are fewer total failures.

(I'll note that my comparisons are besed on using the same vehicle, before and after, but I don't guarantee that is was the best possible. My AV is not heavily scripted.)

[161488303349]

---

WolfBaginski Bearsfoot wrote:

I think there's a bit more stutter, maybe a region crossing process taking several time-slices to complete (is that the right term) instead of locking up the servers until the process completes. The new method doesn't halt so easily. so there are fewer total failures.

 

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I tend to agree about the fewer total failures. meaning that it recovers more times now than before. is kinda marginal improvement bc is the timeouts that killing us all really. like when turn on the Debug Console then can see connections timeout, cant find, dead, etc all the time

+

I been using two kinds of vehicles mostly lately

the starchild rally car which was scripted circa 2007. when that locks up I am toast just about everytime, bc even if i don't have to relog then I am separated from the vehicle and it keeps going on without me

that a problem bc it seems that when a vehicle is say moving by itself at power 30 then it decays like normal when stop applying power yourself directly. but if say has decayed down to 10 when it hit the border then it starts again at power 30. the decay part not seem to be handed off. so it will pretty much go on and on forever all by itself and never stop until it hits a parcel/sim barrier/obstacle

+

the other is my simboard which have a more modern script. it not have anywhere near the same number of problems. but it have the power 30 problem as well

+

edit add: the power 30 a problem bc if it did decay then it would stop close by. so if have to relog then can find it easy and resit. but bc it don't then by time I relog it can be anywhere somewhere

if was going across the border in straight line then can sometimes find it way ahead

if go across while turning then it just spins/tumbles off at some random angle and depending on the angle when it hits the next sim then can go off in some other random tumbling direction

 

[WolfBaginski Bearsfoot]

It's an old suggestion, but this last weekend I have run a few tests with movement interpolation off. This is found in the Network sub-menu of the Develop menu. It stops the wild rides, and you stop at the sim boundary until the crossing is complete. But I also see a lot of stalls and stutters within a region. But what is the cause?

My guesses:

The change in Physics needed to support pathfinding

Bad communication between sim and viewer. I have certainly seen bursts of packet loss associated with the stuttering.

Overloaded regions.

 

I doubt there is a single cause. I have seeb this stuttering without another AV in sight. I have seen it happen over the Blake Sea and over complicated mainland regions.