Mesh Builds do they cause extreme lag

[Leyla Oran]

Since i brought a rather expensive mesh build 2 days ago.  It appears i am suffering from really bad lag. I have turned off many things that appear to have help.  But if this is the case i certianly will not buying any again

My old build i brough ages back was not mesh no problems at all.

Any advise would be appreciated or maybe its just me.

[Amethyst Jetaime]

It depends on the quality of the build.  If they used a lot of high resolution textures on it or laggy scripts in it, it very well could cause you to lag.  Supposedly mesh itself is more efficient and is not supposed to cause lag.  But I think if it isn't efficiently built and uses a lot of polygons in the mesh, it isn't.

You can test it by deleting the mesh house and seeing if your performance improves a lot.  If it does, re rez it and see if performance goes down.  You can then draw your own conclusions about that specific build. 

 

[Leyla Oran]

Thank you so much Amethyst for replying yes i think i might have to do that to. .. Only way to find out i guess. High quality textures it is too shame if i cannot keep it if thats the case.   But lesson learned.

[Madeline Blackbart]

You can also see if it's high poly  (which along with scripts cause more lag I think then textures...not that textures aren't an issue) by turning on wireframe mod. If you turn it on and it looks really dense...it's high poly. It's a misconception that mesh = more effecient...not always. It can be...but only if modelled right. I think the best way to see if it is is to view the build first. If the preview frops your FPS then owning it won't change things. lolz

[Jo Yardley]

To test if the mesh or textures or scripts cause lag, delete the scripts and textures from the building (if it has copy and edit perms of course).

Delete all scripts from it, see if you notice a difference.

Delete all textures (by turn the whole building into plywood) and see if you notice a difference.

Perhaps even make one copy with textures but without scripts, one without textures and with scripts , one without both and one original.

This way you can figure out what the problem is and perhaps keep the building but replace just the textures or remove some of the scripts you don't need.

[Pamela Galli]

I have built 50 non mesh houses and am on my 6th mesh one.  Here are my observations about texturing:

 

With non mesh houses, I often made textures specifically for a particular face or set of faces, but quite often I could make a shaded texture and reuse and/or horizontally tile it. 

 

With mesh houses it is harder to find opportunities reuse a texture.  I usually fit two walls per texture, and these are not small walls. I am  not going to fit two walls on a 512 texture because they will lose a lot of definition. I know some people claim no one can tell the difference between a 512 and a 1024 but I sure can. 

 

Here is the deal:  If the textures in a house are going to lag your computer, you will be able to tell by walking around the demo.  My demo houses are crammed with furniture as well, so anyone walking around inside is going to be downloading a ton of textures, not just from the house.  So it should be possible for anyone with a computer (or connection or whatever) that is going to lag, to know about it up front.

 

My mesh houses so far have been quite detailed and complex, but the one I am working on now is a simple contemporary build consisting mostly of cubes, in which I will be able to reuse more textures than I have so far.

 

[Sassy Romano]

Scripts cannot cause lag at the viewer. They execute on the sim.

 

 

[PeterCanessa Oh]

Just because no-one's mentioned it yet: the 'standard' way to measure how much affect a build - mesh, sculpt and/or prim - is expected to have is to right-click > edit it and look at the 'Land Impact' (LI) figure.  This replaced the old pre-mesh prim count figure and the lower the better, for something that still offers the appearance/functionality you want.  Not knowing what type of object you're talking about I can't offer any 'sensible' or average figures.  I suspect, in fact, that any attempt to find out the average LI of, say, a residential house, would cause howls of outrage from builders above that number.  It shouldn't; they should just point out in what ways their builds benefit from the higher poly-count or whatever.

[Leyla Oran]

Thank you so much everyone for advise much appreciated.  Will be taking new one down later today and re putting up my old one .  Scripts I already knew about so always take extra care with what I put down I simply hate lag don't we all.. lol.  Land impact I will now take an extra interest in and yes when I first saw this build I did lag a lot at the demo I thought it was just the place and would be ok once I had on my own land oh well ..will probably post the outcome ^^

 

[IvanBenjammin]

Check the land impact of the house, specifically the 'more info' pop up. If your download or physics weight is high, then its the fault of the mesh, otherwise its likely textures.

Because you don't have an actual 'land-impact' value for textures, a lot of people have a very casual attitude towards their use, when they're actually the biggest cause of lag and poor performance.  Yes, mesh items can be inefficient and laggy, but only when they're built badly - the actual cost of downloading polygon data is tiny in comparison to textures.

And if your house is using normal and/or specular maps, you're downloading 3 maps for every surface instead of one. A single 1024x1024 texture is close to 2mb of data, more if it has an alpha channel.  This is why developers for games reuse textures all over the place, all the time.

 

[Leyla Oran]

Well very pleased to say I log in fine now.  First I set my log in to a different place on my home land as far away from the build as possible.  Logged back in wow what a difference that did make.  Instantly deleted the mesh build put my old one back up. No more lag so I think this is a very valid question answered YES  some mesh builds do seem to  cause extreme lag they take way too much band width I did check this as well loading time for this build was awful.  It stated in info before I brought the build make sure you have a mesh viewer and extra prims .. I do and I did. I think its the textures on it superb quality but just too much.. I have never in all my days on SL had this problem before. Thank you so much for all the advise much appreciated I know more about builds now then I ever did

[Jo Yardley]

So what part of the building was causing the lag?

Textures, scripts?

[Sassy Romano]

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Jo Yardley wrote:

So what part of the building was causing the lag?

Textures, scripts?

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Cannot be scripts, scripts execute on the server, they cannot cause viewer lag.

[Pamela Galli]

I am confused -- so all these bazillion resize and other scripts don't cause lag?

[Sassy Romano]

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Pamela Galli wrote:

I am confused -- so all these bazillion resize and other scripts don't cause lag?

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They can lag the sim but not the viewer.  Sim lag will be characterised by different metrics, all easily viewable in the statistics pane, script time, frame time and so on.

If the viewer fps is suddenly laggy, it's not a script that's doing it.

Plus if the sim is fine without the object rezzed but seriously bad with it rezzed, it would take some pretty amazing effort for a single, normal, non deliberately griefing scripted object to pull a sim down to its knees.  I have a utility that insantiates thousands of scripts and doesn't even do that.

Plus, for the past few years, scripts have been given low priority behind other things so don't impact like they used to.

[PeterCanessa Oh]

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Pamela Galli wrote:

I am confused -- so all these bazillion resize and other scripts don't cause lag?

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Scripts have the lowest priority for server processing so, effectively, they can only lag other scripts - WHILE processing.  The highest priority and therefore lag-impact is handling avatars so you'd expect a busy place to be more laggy.  After that is physics - lots of balls bouncing around, etc, - then all the rendering and other stuff and, finally, if the sim has time, maybe, doing some script stuff.  If some script is hogging the script time it'll only, at worst, make the scripts in everything else react more slowly.

It has been this way for several years.  The BIG impact scripts can have is when someone crosses sims (or teleports).  Then the sims concerned have to pass a, potentially large, chunk of information between themselves.  This used to cause the 'sim freeze' problem and although it's been modified can still cause a slowdown when an avatar with loads of scripts arrives.

[ETA: Oh yeah, and it is technically possible that scripts take so much memory in total that a server has to use virtual memory, which is waaaay slower than RAM.  That's why LL mooted script limits a while ago, but didn't do anything about them.]