Av render cost (revisited)

ARC is not a reliable tool for many reasons many of which are stated in this thread. The bottom line is ARC deals primarily with client side lag and the numbers do not communicate reliable impact on server performance as high numbers do not necessarily mean that an avatar is impacting heavily on the server and low numbers do not mean an avatar is not impacting heavily on the server.

Indeed one of the newer griefer tricks is just porting into a sim with a huge load of scripted prims/attachments on default avatar (ruth seems popular for this..)

Low arc, high sim impact

Ahhhh...that explains something weird I was wondering about. Since I don't use a viewer with the ARC feature, one day in class I didn't have time to go to the Beta grid first to check mine out and asked what it was once I got to class. Four people had four different numbers for my AV. They were minimally different, but I thought that odd. Your post answers that.

I'm not sure it ever was one, so much as people were suddenly aware as to the source of the lag. Things have been improving over time as most builders have improved their habits to reduce the rendering cost of their products. That being said, the goal is to keep it in the green, yellow at worst when you're in busy areas. Save the stuff that pushes you into the red for formal affairs and photo shoots when looking your best actually counts for something.



Around 1.4 million. Just before my feeble old laptop crashed from the strain. It wasn't too long after that info display was introduced and there were still people who were having contests to see who could create the laggiest look possible.

I would shop for hair you like that doesn't push your ARC so high (it doesn't affect just you after all, but everyone who has you within their field of view out to their draw distance). Save that hair for more showy occasions.

That's not flawed, that's expected behavior. Transparent textures are considerably more difficult to render. It's among the most difficult things for a computer to render, since you still have to render what you can't see, as well as what's behind that transparent object. It's why you see the framerate drop so sharply in games like Half Life or Portal when you're looking through a window.

The only difference between a sculpty and a regular primative is the shape of the wireframe it's based on. Complex sculpties are obviously going to be more difficult to render than simple prims. On the other hand, a few sculpties to make, say, a studded boot, is going to be dramatically easier to render than the same boot made out of the hundreds of individual prims that it would take to do it with basic prims.

My day to day avatar (seen in my profile pic and forum icon) registers around 250 on the ARC and I'm almost certain there's not an attachment that isn't a sculpty.

I can't think of any furry that's spent any serious time on the mainland back then that didn't have that problem...if there's any segment of the SL population that benefitted disproportionally from that feature, it's gotta be the furries.

That's not a problem with the feature: that's a problem with people - selfish, stupid vanity.

It's not meant to be a scale of lag. It's more like a golf score, the yellow is par; points off for what is most likely to stall the graphics pipeline. The rationale for the points score is spelled out over at http://blog.secondlife.com/2008/05/01/who-me-yes-you-couldnt-be-then-who-introducing-avatar-rendering-cost/

Bottom line if for the TL;DR crowd: The number is not scaled to actual lag, but rather a measure of how difficult an avatar is to render. In general, the higher the number, the lower the framerate when that avatar is in view. It's useful because it allows you to pull some street clothes together for day to day use that aren't going to singlehandedly push someone on a low-end machine into slideshow when you walk into view and minimize your individual contribution to the lag in busy areas. Flexi prims and particle emitters are the biggest contributors to video lag.

You miss the point. A single transparent texture is not a greater impact on a graphics render than a max prim per attach point av... yet the one with a single transparent texture has had higher ARCs every time.

Setting aside the fact that the ARC doesn't count things like texture sizes (and there's avatars out there with 1k solid color textures, yes really), we're not competing against par. You can't eliminate the inherent cost of the avatar on the graphics pipeline. If there's 40 avatars with ARC of 20 each they're still going to cost you more to render than one avatar with an ARC of 10,000, so ARC is not "avatar rendering cost". The avatar is downright expensive. Worrying about an extra "2000 magic points" from prim attachments is just a waste of time.

If yellow is par, then red should start at 6000.

Oh, and pretend I don't know what "TL;DR" means, because I don't.

AV render cost probably evens out in a crowd -- there's going to be some AVs who have near zero cost and others on the high side.

It was good for me to see my own cost, made some adjustments, like trading my former 800 prim shades (pre-sculpty and I never noticed how many prims) to a pair which are just a few prims.

I can see how it would be easy to dis someone on account of their likely unknownest-to them high cost rig.

I think a strategy for someone who bent on such notification is to ask said high coster if they known how to view their cost.

-iw

We're not talking about just any textures with an alpha channel, we're talking about 100% transparent textures and prims with llSetAlpha(0, 0);... they shouldn't be rendered at all. And yet they score the ARC up.

Well, only in the sense that you might be telling someone with a high end PC that they need to scale back the experience they paid for to help support your aging computer in a virtual world designed as relatively limitless in what you can do. If you land in a group of 5 people with monstrous ARCs is it up to them to adjust to your experience, or you to go to high end, keeping in mind that Linden Labs is TAO of Lindened to aim for cutting edge, and so essentially intended best for people with high end machines ?

Did you (not you specifically, the struggling renderer) performance tweak your computer for SL, adjusting things like draw distance and detail ? Can you minimize your issues by zooming in on a less graphics intensive place and not watching a whole club full of dancers for example ? This does not even count that framerate is only one aspect of lag.

I have a midrange machine, never have issues rendering, unless the db servers are struggling, because I pay attention to the above. If I am struggling to render, I do not look at arc's, I pay attention to the area my cam is focused on.

I mean lets face it, SL is built around a users self centered experience, and ARC only gives you an indication of where your machine struggles. I am not sure which relative end of the selfish is selfish.

ARC is a performance measurement relative to your computer.

Interesting thread. My own experimentation so far suggests to me that it is flexis that really pop up the ARC number, as opposed to transparent textures or sculpty attachments.

I did wonder for awhile with hair, as it's often both flexed and has transparent textures, but comparing non-transparent textured prim clothes in flexied vs non flexied state seemed to pinpoint the higher cost to the flexied state.

oh, just to add, the number of flexis reflects that too.. a skirt with 40 flexied panels is definitely higher cost than if you can manage to do one with 20.

Part of that is due to the fact flexi is rendered client side. The serve sees it as a solid prim vs a flexi prim

And the prim count - people are more likely to have 200-prim hair, each prim with a bit of transparency, than they are to have 200-prim objects with all flexi prims..

depends on their intent...

If they're in a tent then shouldn't object occlusion solve the problem?

I actually did do an av on an alt... all no texture prims, 254 prim attachements on every single attach point...

No flexie..

Was lagtastic as could be. But low ARC

Yao Ogee has an avatar that consists of invisiprims to hide the avatar mesh, plus 6,000 tiny spheres arranged in a cloud around the avatar.

Now.. Make an attachment... 254 flexi/hollow cubes with *Default Transparent Texture on all faces. No lag at all (until you edit) but an ARC of epic proportions. (^_^)y

What about having all hair, jewelery, clothing etc in stores labelled with an ARC number?

Rock

Given that ARC is highly misleading, at best, what purpose would that serve?

It would turn getting dressed into a trigonometry exercise.