Harper's Reducing Your Avatar Rendering Cost How-To

Avatar Rendering Cost or ARC remains one of the more controversial features introduced by the Lindens in recent months: a clever means of adding a social pressure mechanism against avatar enhancements which cost lag, on one view; on the other, a confusing, arbitrary metric that's sometimes encouraged unfair ostracism and prejudice. 

That to one side for a moment, Harper Ganesvoort has a weighty how-to guide for reducing your own ARC, with point breakdown and examples.  Using her methods, for instance, she's been able to SL parties in this chic cocktail number with a modest ARC of just 172.  Find out how with Harper here.

Image: harperganesvoort.wordpress.com

Update, 4:05pm: Cajsa Lilliehook and Gidge Uriza wrote an earlier ARC advice guide also worth a look, charmingly entitled, "Hello, We're the ARC Police".

Comments

[Seven Shikami]

Kids these days (yay generalization!) don't seem to get the difference between LAG and SLOW FRAMERATE.

LAG = Unresponsive communications between you (client) and SL (server). This can be due to network conditions or due to the sim being overloaded and unable to keep up 100% speedy operations on all scripts and clients.

You type a line into chat, it appears half a minute later... that's lag. You try to move and it's like pushing through syrup... that's lag. You're playing a game and visually its updates like moving game pieces around or telling you things in chat are stuttering or slow, that's lag.

SLOW FRAMERATE = When your computer's just got too much stuff to draw, and it can't draw it at a good rate of frames per second. This is entirely client side and has nothing to do with lag. You can make things better by turning off some bells and whistles in graphics options.

Where it gets fuzzy is when someone has fifty thousand flexy prims on and 2048x2048 textures, that's slow framerate... AND an initial burst of lag as the server pushes all the data down the pipe to you. But once you have it loaded it's no longer a lag problem, it's a slow framerate problem.

So, ARC is a measure of both the initial lag caused by loading an avatar's resources, and the slow framerate. Since it's just a burst at the start, the real issue ARC is measuring is slow framerate, NOT lag.

Does this mean you're A-OK with your blinged out facelight loaded flexy and shiny everywhere avatar? NO! You're making the server push all that stuff down the pipe to people, which is a pain on it. But it's not nearly as contributory to lag as, say, a badly written scripted AO/HUD tool that puts constant pressure on the server to run its crazy calculations.

You wanna kill off lag? Ask people to remove SCRIPTED attachments first, and visually horrible ones second.

[Harper Ganesvoort]

(Also posted in comments to Seven at my original article....)

Your points are good; and I think we can bridge the semantics question between “lag” and “slow framerate” by just saying, “garbage that increases load.” In the end, it’s the load of rendering all the stuff that slows things down, client or server. (Actually, we shouldn’t forget about the landscape and buildings, too; but we can’t do a thing about them except stay away from the region. :)

I would suggest this about scripts: even if they’re well written, they can add to the “garbage” cost, because they are a part of the load the server has to put up with. I found this out at Hair Fair a few weeks ago, when I took off my walk override — the only AO I usually wear — and heel sounds, and my ARC dropped by maybe 100-200 points. So you’re correct about removing scripted stuff first; I’d just make it general, instead of focusing on the trashy stuff. I try to remember to strip those off when I go into a high-load region now. Usually you’re at one of these to do something else besides walking and clicking your heels, anyway; you dance at Frank’s Place, listen to Ira talk to his guests at Science Friday, etc. You don’t need an AO on for those places.

[Ann Otoole]

ARC is invalid along with the opinions of anyone that gives ARC a second thought. Buy a real computer. Or go play habbo hotel. Secondlife is for adults.

[Nightbird Glineux]

Where are the articles showing how to measure and reduce *build* rendering costs?

[Jane2 McMahon]

The day they design a good system skirt, I'll give a crap about ARC, or reducing my footprint, or whatever the stupid buzzword of the day is that uses vague, bogus measurements to further some pronouncement that somehow SL problems are "my" fault.

[Nightbird Glineux]

@Jane2 McMahon: You go girl!

[Harper Ganesvoort]

ARC is invalid along with the opinions of anyone that gives ARC a second thought. Buy a real computer. Or go play habbo hotel. Secondlife is for adults.

Needless to say, I prefer to regard my words as pearls of wisdom, something that should be committed to memory and recited by schoolchildren every year at major national events....

(Two men in white coats sneak up behind Harper with a butterfly net....)

[JoeBob]

"ARC is invalid along with the opinions of anyone that gives ARC a second thought. Buy a real computer. Or go play habbo hotel. Secondlife is for adults."

"The day they design a good system skirt, I'll give a crap about ARC, or reducing my footprint, or whatever the stupid buzzword of the day is that uses vague, bogus measurements to further some pronouncement that somehow SL problems are "my" fault."

A gracious respnse by was offered by Harper above, but really, what do these two comments indicate?

Methinks they scream that selfish, stubbornly "me first" people are indeed everywhere.

[Miriel Enfield]

Since it's just a burst at the start, the real issue ARC is measuring is slow framerate, NOT lag.

No, it's not. While it measures things that contribute to low fps, it does so so poorly as to be misleading. A sculpted prim, for instance, has way more polygons than a box, but ARC counts them both the same. There's a huge difference in the fps hit caused by fifty sculpted prims and the fps hit caused by fifty boxes, but you wouldn't know from looking at the ARC numbers. It's nearly useless, and it's probably better to just ignore it under most circumstances.

(Also, the lag/poor fps distinction is not terminology I've ever heard anyone use before. Stuff that strains the server is server lag, stuff that strains the user's computer is client lag, and issues with the connection between the two is network lag.)

[Harper Ganesvoort]

Something tells me this is a subject that could be debated endlessly (grin).

[Truthseeker]

"There's a huge difference in the fps hit caused by fifty sculpted prims and the fps hit caused by fifty boxes, but you wouldn't know from looking at the ARC numbers."

That right there is why this 'debate,' such as it is, keeps going on, Harper.

Drama-queenie-ARCpolice are screeching & browbeating & stripping each-other in public over the Terror-Alert-Status color-coded numbers over their heads, meanwhile the designers who have been diligently studying & attempting to *use* this 'metric' (lol omg) are coming to the realization that the numbers basically lie (thru omission, at the very least)...

I generally wear about 450 prims on my av, mostly twisted and/or cut torii. By doing nothing other than turning off the kewl prim-effects (basically the only things ARC measures) and blanking all textures (thankfully we don't get penalized for applying color...altho...why not?), I've reduced my score from 2900-3900 (depending on which cuffs I wear & which staff I carry) to *88*. That's right, eighty-eight. An impressive drop, no doubt, but methinks we're not getting the whole story here...

And of course, the truly sad thing is: say the social-ware aspect does its job and everyone's walking around bald & nekkid @ Hairfair or Burning Life (for instance)... the shit's STILL gonna lag!! HORRIBLY :-/

Oh, and P.S. why, exactly aren't local lights (as part of an attachment) counted?? Every-bit as much of a client-side operation as flexi or particle-rendering, right?

and please GOD, don't let the reason be something like:

RATIONALE: What're you, nuts?? If we make 'em take off their *facelamps*, then they'll go back to screaming at us about WindLight!!(>.<)

So um, when's that town-hall with Ramzi & Runitai scheduled for?? Yeah, didn't think so :-(

Oh, goodness, I seem to have done it again... -_-;;