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Pathfinding Panic

August 8th, 2012 by Marianne McCann

Usually I spend a lot more time being thoughtful before I post here. It means my entries are usually few and far between but, I hope, worth the wait. With all the brouhaha about pathfinding today, I opted to hop right into it.

First, let me start with a critique for anyone from the Lab who might be reading this: this is why you need to communicate. I am doing your job here, but if you guys would do a better job at communicating to your own paying customers, people would get better information than what I’m about to lay down here. Please rethink your communications policies.

So today Pathfinding code went live on the main channel of the Second Life server software (the code that runs all the regions on the grid). Tomorrow it hits the LeTigre and BlueSteel Release Client server software. That will mean that every public region on the main grid will be running server software with pathfinding code, including a Havok physics update.

Pathfinding is something the lab has been hammering on for months now. Makes prims that can act sort of like critters. They can wander, attack, evade. Kinda cool, if you’re into that. I’m not so much, but who knows. Maybe I’ve just not see the “use case” that I can use.

Meanwhile, a blog for a third party viewer went out, claiming that the pathfinding code will use up to 18% of your sim resources, and provided information on how to either optimize or disable pathfinding for your region.  This, in turn, led to what one might call “the usual panic.” Instantly, it became fact that “the evil ol’ lab was out there hurting its users, and it was up to all of us to fight back my immediately disable the code.”

The usual talking points were trotted out. The lab has clearly not tested the code. It is deliberately trying to “kill” SL by rolling this out, etc., ad naseum.

The thing is, this code did not just pop up on the main grid today. It was used in The Wilderness project and Hairy Hippo Fun Land months ago. It was sprinkled around the grid then as well as a “PF” release client. Five weeks ago, it was promoted to the Magnum release client server software, and has been chugging away ever since. Just ask anyone who uses mesh vehicles, and they’ll tell you all about the fun of trying to cross out of a Magnum viewer and dealing with the mismatch in Havok versions.

But what you won’t hear much about is how their regions were crippled by a staggering 18% of sim resources being tied up in pathfinding. The regions themselves have been running fine, albeit there have been a few bugs along the way — and there are still a few things that need to be ironed out. Some issues with the way some prims travel on the navmesh, for example.

Now, to be fair here, the code can use some resources. It is designed to throttle itself, however. It does not use all the resources all of the time, and is intended to deliberately not take resources from other uses. It is not going to be crippling your region.

So really, what I want to say is this. Enough with the knee-jerk reactions. I understand that the lab has not always thought things though, and was even fairly antagonistic to their userbase during the “M” era. Their current lack of clear global communication, too, doesn’t help to get people beyond that time.

But rather than seeing a blog post and instantly reacting to shut it all off, do your own tests. Go visit other regions that are running the code (which by the time you read this may well be all of them). Heck, try your own region on for size, and see if its running poorly compared to, say, this time last week. Don’t take the word of any blogger — even me. Go look with your own eyes, and form a rational opinion of your own.

9 Responses to “Pathfinding Panic”

  1. Crap Mariner Says:

    I sent out a crapogram to the Five Islanders, told them to keep an eye out for oddness and the usual Labbie propensity for trimming their toenails with a Gatling gun, and that there should be an emergency shut-off switch for it should it be necessary.

    I wouldn’t call my position as accepting and welcoming based on the Lab’s history for using an assortment of bootlickers for testing, with the occasional critic that they end up ignoring anyway. (Ah, Esbee. You’re not missed.) But I wouldn’t call it knee-jerk reaction either. Call it a cynical “Keep your eyes open, and be prepared.”

    -ls/cm

  2. Marianne McCann Says:

    Seem that too me is a reasoned response. Being wary and watchful for issues? Ya, that is smart. Panicking about it before you even look at it, that’s quite another.

  3. ZZ Bottom Says:

    Did all you said and decided to disable path finding on my region, cause its private, is not linked to another 1 and we don’t intend to use path finding (For GOD’s sake i have it since 5 months ago on my OSGrid regions plus Npc’s that Sl will never have, just go and visit ZZTT,1 2 3 4 and TTZZ).
    But off road car builders, that where testing for long the new mesh ground where assured that the roll out would nveer happen before they solved the issue that makes them useless, Guess what? They where utterly ignored!
    And i did some tests since at least last month, on a sim that was created to have a off road drity track build on natural landscape and i can assure you, is not fun now!
    Plus, with so many needs, like solving sim crossings, old landmarks, mesh deformer and all the old but stiull well alive dooomed bugs, playing with a feature that none of it’s users basis requested is just simple stupidity!
    And hurting (you can read them all posting on Sl foruns!) a part of the community (vehicles builders) will not retian new users, just make the old ones move to Open Sims, that sooner will have a physics engine, way better then Havock, mark my words (Intel + Bullet physics!).

  4. Indigo Mertel Says:

    Thank you for posting this, Marianne. Well done.

  5. Crap Mariner Says:

    After reaidng Inara’s post and seeing the statement that sculpties can be potentially counted up to 2 LI, I take back my reasoned response.

    If that’s what I think it is, that’s going to raise a HUGE stink, and instead of this being seen as an incentive for people to create and convert to more efficient Mesh constructs, it’s an increase of prices on existing sculpty builds.

    Or am I jumping the gun on this?

    -ls/cm

  6. Qie Says:

    The panic over Pathfinding is overblown. Yeah, maybe some super-high-traffic regions will opt to turn it off. And yeah, there’s bound to be some of the disruption that comes every time a developer glances in the general direction of Havok. But it’s such a ripe opportunity for FUD, it could hardly be passed up.

    I’m behind on the LI stuff, but if it’s changed such that sculpties can only count 2 or less even when linked with Mesh, it would be a big improvement over the status quo ante. Not good, but lots better (*if* that’s what’s happening now).

    All that said, it’s a very good point re: “bootlickers” — a result to be expected when one uses NDAs to screen out everybody with a lick of sense.

  7. Marianne McCann Says:

    Yes, that part *is* concerning to me. What isn’t clear from my perspective is this: is that specific to *physical* objects or not? Physical objects set to convex hull? It’s not entirely clear, IMO. I’ll need to do some poking.

  8. Wolf Baginski Says:

    I’m afraid the whole pathfinding business has only hardened me in my cynicism about the Labs. They shouldn’t need people such as yourself to do their communication.

    Maybe you should send them a bill for services rendered?

    But the process has also been badly mismanaged. You know how they laid out the tests, using the Magnum RC. At one level, they blocked one-sim-wide water routes to Mesh vehicles. More subtly, the pattern of regions, in areas such as the Blake Sea, made the sim-crossing problem the big practical issue. I didn’t see anywhere where competitive sailing could have been done in Magnum-only regions, and that would have been a good test of both Havok 7 in general, and the effects of Pathfinding. Even the Pirate Battle Zone was mixed channels, and hence more a test of sim-crossing than anything else.

    This was not a well-planned test, and we could face the same hassles every time Havok is upgraded, unless Linden labs de-digitate.

  9. Trinity Dejavu Says:

    I really don’t see how the lab can ever win.

    OMFG PANIC LL ARE TRYING TO KILL ME.

    There is lots of communication from the Lab if you are so inclined but for some reason all those poorly attended office hours (or whatever they are called now) just don’t count.

    If it’s not enough that things are developed in the open over a period of months while giving residents constant access to the people involved, then I have no idea what may count. Probably nothing. The front page blog really isn’t the place to put the finer technical points of their latest behind the scenes wizardry.

    @Wolf – All dev channels are OPT-IN, how is it the Labs fault if one half of that thing you like opted into a RC and the other half didn’t.

    Bottom line to all this is the Lab just gave everyone a HUGE gift. More prims on your land and better interactivity.

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