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Pamela Galli

LL: Mesh is useless?

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Drongle McMahon wrote:

Here is a couple of simple rules-of-thumb....

1. Always join part meshes up menough that the results have download weights greater than 0.5. Otherwise the server weights will dominate.

2. If you join up your meshes enough that the parts have download weights greater than or equal to 1.0, then you will never see and increase in LI when you add a script.

In fact it's a bit more complicated. Since the unrounded download weights are added up for the whole linkset, a part with a higher download weight can compensate for some with weights less than 1.

There is a price for joining, in the higher LI from the increased size and more distant LOD switch. There may be a gain from joining in that you can use a simpler combined physics shape, which matters if the physics weight is high.

Finally, the un-coordinated LOD transitions of separate mesh parts can be disconcerting, so joining can provide a benefit there. Conversely, when the separate parts are specifically designed to separate small high detail parts and large low detail parts, the closer LOD switch of the high detail parts can achieve good savings in download weight while LOD behaviour is still acceptable.

Thanks -- I actually understood 2/3 of that. :-)

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Actually, I think there will be a super high amount of people making super inefficient mesh with crazy land impact or display costs, and only a small number of people making any thing that could be considered efficient. This, I fear will lead to many frustrated consumers and false stereotyping of mesh items. Hopefully, things get worked out in both marketplace and inworld search, so that all the really good merchants and creators float to the top. I have little hope of this tho.

 

On the bright side, I sold my mesh bridge the other day, and the customer messaged me later that day to tell me thanks for saving him over 200 prims on his sim, and how much better mine is than the 1 he was using. I think my next larger object will probably be a boxing ring. I think it's a perfect candidate for mesh.

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Medhue Simoni wrote:

Actually, I think there will be a super high amount of people making super inefficient mesh with crazy land impact or display costs, and only a small number of people making any thing that could be considered efficient. This, I fear will lead to many frustrated consumers and false stereotyping of mesh items. Hopefully, things get worked out in both marketplace and inworld search, so that all the really good merchants and creators float to the top. I have little hope of this tho.

 

On the bright side, I sold my mesh bridge the other day, and the customer messaged me later that day to tell me thanks for saving him over 200 prims on his sim, and how much better mine is than the 1 he was using.

Most people find out pretty quick how important prim count is.  There is not much market for high prim stuff of any kind. Of course, there is no cost to a listing on the MP, so high prim mesh will stay there forever, but inworld presence of high prim merchants will, I suspect, dwindle rapidly.

The number of those left standing -- those who have culled info about SL-specific mesh from the various sources (and figured out which are obsolete) and made some sense of it -- I think will be small indeed unless LL undertakes collating and simplifying the most current information in some central repository (like a well organized manual), so the information will be accessible to more people.

 

 

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Wow, this was an active thread. 

It took me a while to get through it all. I'll try to hit a few important points:

You can't compare different objects. Just because they have a similar number of triangles in the source application, doesn't mean their weights will be the same. If you'd like a more detailed explanation, send me the collada files for your two objects.

Create your own LoDs. This will give you complete control over how your object is perceived and will likely have a big impact on LI.

Create your own Physics shape - or - use linked prims for collision. Automated systems are no replacement for a craftsman who knows the intended use of an object.

Because LoD is based on relative size, creating one combined object allows you control the overall shape as it passes through the LoDs. Using multiple ones will mean that smaller parts will degrade earlier. It's a tradeoff. 

We do read the forums, but obviously not every thread. Users, as you've seen, often know as much as we do.

Oh documentation. How I miss thee...

Charlar

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Except for worn meshes. No1 really knows what the display cost is for a mesh. No1 advertises that. Most creators still don't think it matters what the cost of an item is, if it is worn. And, more people go into making worn items just to not have to deal with prim amounts.

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Charlar Linden wrote:

 

We do read the forums, but obviously not every thread. Users, as you've seen, often know as much as we do.

Oh documentation. How I miss thee...

Charlar

:-)   Yes, when the dust settles maybe something written by a non tech person who nevertheless understands the technical stuff and can break it down for the rest of us? I know that is a tall order. Not everyone can do that sort of thing.

 

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Pamela Galli wrote:

:-)   Yes, when the dust settles maybe something written by a non tech person who nevertheless understands the technical stuff and can break it down for the rest of us? I know that is a tall order. Not everyone can do that sort of thing.

 

Heck, I'm a techie and hardcore math geek myself and some of the details involved would make my head spin without the stuff Drongle and a few others have posted on here. I'd say the ideal "team" for writing that doco would be Drongle who's done the in-depth practical research, Charlar who knows the code so well he probably reviews patches in his dreams (hint, Charlar, thats a sign of overwork!) and Gaia who's been documenting it for "general users" since the early days of beta...

Of course whether any of that crew would have the time to do it is another matter :)

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I still don't get it, I guess.  (Yes, I admit it:  I am a history/English major!)

1) I uploaded a table leg w/ 629 faces, using the model for the top 3 LODs and 12 for the lowest.  4 of them linked = 2 prims.  Good -- but the LOD was not as good as the previous version of the leg.

So I decided I would try what I understood to be the advice of many here, which is this:  I made a low LOD model with 28 faces, and then another plain one with 4.

I used the high poly model for the first two LODs the 28 poly for the 3rd, the 4th the 4 poly one.  I used the 4 poly one as the physics model.

I got this error:

 Screen shot 2011-12-05 at 11.54.06 PM.png

 

BTW, all the models had the same one material assigned.  I did not know what to make of the error. I mean, aren't the lower LOD models supposed to have a different # of faces than the high one?  I got the error a couple of times, but fiddled around with it and it magically went away. 

However, the lowest upload I could get was 4 per leg. So I threw in the towel. I will keep the low PE one. I still have no idea what I did wrong.

2) Today I re-uploaded a joined chair seat with 4 legs.  I had uploaded these before, and gotten a PE of 2, but I slightly edited the legs -- but now the model uploads as 9.

I uploaded the two models with the same parameters I upload almost everything:  the model for the top 3 LODs and no more than 25 for the lowest. Same size, nearly identical meshes. So far I have not been able to get the slightest idea what might account for a more than 4 x increase in PE.

Now. Obviously there are those for whom this is all supremely simple, and who wonder what is my problem. But if people like me -- motivated, dedicated, hard-working -- are finding just uploading a mesh with a decent PE so very difficult, then something is wrong.  When I get an error message like that above, for example, how am I supposed to interpret it? If I had a product that was causing this much confusion for my customers, you better believe I would be re-evaluating everything about it, from how it functions to the instructions.

So LL: You have launched a product. Where is the instruction manual?

 

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Da5id Weatherwax wrote:


Pamela Galli wrote:

:-)   Yes, when the dust settles maybe something written by a non tech person who nevertheless understands the technical stuff and can break it down for the rest of us? I know that is a tall order. Not everyone can do that sort of thing.

 

Heck, I'm a techie and hardcore math geek myself and some of the details involved would make my head spin without the stuff Drongle and a few others have posted on here. I'd say the ideal "team" for writing that doco would be Drongle who's done the in-depth practical research, Charlar who knows the code so well he probably reviews patches in his dreams (hint, Charlar, thats a sign of overwork!) and Gaia who's been documenting it for "general users" since the early days of beta...

Of course whether any of that crew would have the time to do it is another matter
:)

I can just imagine if I told my customers I was too busy to provide instructions for my things. :matte-motes-sarcasm:

 

I would add Asha to that list. She really makes it simple even for ppl like me. But LL needs to pony up for paying people to do the job, because it is a big one, and I don't imagine a very fun one.

 

 

 

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Pamela Galli wrote:BTW, all the models had the same one material assigned.  I did not know what to make of the error. I mean, aren't the lower LOD models
supposed
to have a different # of faces than the high one?


Well, the fact that "faces" is someting in 3D modelling and something different in "Second life slang" has been discussed a lot. I remember my own thread even:

http://community.secondlife.com/t5/Mesh/Changing-the-SL-notation-from-quot-Face-quot-to-quot-Surface/m-p/894903/highlight/true#M1035

And that has been surely discussed at a few other places.  And yes, Charlar, i remember that it is almost impossible to get rid of the SL slang.

But i still want to propose to at least agree on a "better suited slang". I sometimes find "texturizable faces". I proposed "surfaces". Others got their own creative wordings and i just invented another one, see below  :)

Anyways what is meant here is:

(SL-)Faces :== Not necessarily connected collections of  polygons (quads or tris) on your model using the same texture.

I propose to abbreviate that by: "Necopot" :matte-motes-evil:

Rule: All LODS need to have the same number of Necopots... ermm "(SL-)Faces".

If that number varies -> Error message as seen above.

 

We would have much less fuss if the error messages would be improved by telling what exactly is going on (how many Necopots :matte-motes-wink-tongue: does the importer expect for example ? And on which LOD is it wrong for the importer ?

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Gaia Clary wrote:


Pamela Galli wrote:BTW, all the models had the same one material assigned.  I did not know what to make of the error. I mean, aren't the lower LOD models
supposed
to have a different # of faces than the high one?


Well, the fact that "faces" is someting in 3D modelling and something different in "Second life slang" has been discussed a lot. I remember my own thread even:

And that has been surely discussed at a few other places.  And yes, Charlar, i remember that it is almost impossible to get rid of the SL slang.

But i still want to propose to at least agree on a "better suited slang". I sometimes find "texturizable faces". I proposed "surfaces". Others got their own creative wordings and i just invented another one, see below 
:)

Anyways what is meant here is:

(SL-)Faces :== Not necessarily connected collections of  polygons (quads or tris) on your model using the same texture.

I propose to abbreviate that by: "Necopot" :matte-motes-evil:

Rule: All LODS need to have the same number of Necopots... ermm "(SL-)Faces".

If that number varies -> Error message as seen above.

 

We would have much less fuss if the error messages would be improved by telling what exactly is going on (how many Necopots :matte-motes-wink-tongue: does the importer expect for example ? And on which LOD is it wrong for the importer ?

As far as I know, all of the models have the same # of Necopots :-)  One.  Each has one material and one texture. As far as I know, that is. So, still confused about what the error message meant.

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Pamela Galli wrote:

As far as I know, all of the models have the same # of Necopots :-)  One.  Each has one material and one texture. As far as I know, that is. So, still confused about what the error message meant.

That's why i added the last note about less fuss if the importer would tell in more detail about what it laments. Have you looked at the well hidden Secondlife.log ? It would be cool if the error message would mention where the log is on my computer. That would help a lot already. It would be cooler to just see the excerpt from the log. Oh... and if the mesages in the log would be a bit less cryptical.. that also would help a bit...

Well, i better stop :)

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Gaia Clary wrote:


Pamela Galli wrote:

As far as I know, all of the models have the same # of Necopots :-)  One.  Each has one material and one texture. As far as I know, that is. So, still confused about what the error message meant.

That's why i added the last note about less fuss if the importer would tell in more detail about what it laments. Have you looked at the well hidden Secondlife.log ? It would be cool if the error message would mention where the log is on my computer. That would help a lot already. It would be cooler to just see the excerpt from the log. Oh... and if the mesages in the log would be a bit less cryptical.. that also would help a bit...

Well, i better stop
:)

I vote LL employ* the above listed team to do this kind of stuff, if they want mesh to be widely adopted. (* I mean, pay them for crying out loud.)

I just feel so disappointed that I have this new chair leg that Nacy fixed for me and I will not be able to use it. And I don't really have any idea why.

 

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"Rule: All LODS need to have the same number of Necopots"

Now I am confused. I guess it all depends what viewer version people are using, but I thought that was the old rule. and that the new rule is that the lower LODs can have a subset of the Necopots in the high LOD, but they must each have the same name (material attribute in <triangle> or <poly> tag) as one of the high LOD Necopots. Was that reverted? Or is that error message from an older viewer?

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What I'd like to know is why you'd need any more than 100 - 200 trinagles for a bed post. And why you are uploading the bed post and not just combining it up and pulling it in as 1 mesh. I've seen quite a few super high quality meshes that use 5 1024x1024 maps for a chair or a sofa. This is really bad practise and if I did this I'd loose my job (I'm a game level and environment designer irl). You should use 1 map for a 3 peice suite. If I was designing a set of furniture for an apartment (including bathroom, kitchen, living room, dining room, master bedroom etc) I'd use 1 or 2 1024 maps FOR THE ENTIRE COLLECTION!.

 

For furniture used inside depending on it's size you'd want the lowest and possibly the low LOD's to be 1 triangle (so there not visible) as you are unlikely to see the mesh from that far away.  We were given mesh to help make SL run faster and to help optimize the world a little (did you know all prim and sculpts are 1024 triangles, even the cube)

 

Also remember this: "A workman always blames his tools". I'm building an entire city in mesh, and everything works just as it should. infact sometimes the costs are lower than expected

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Prims are not quite that bad. The undistorted high LOD cube is 108 triangles. It gets to be more with torturing. It's quite instructive to go into wireframe mode (Developer->Rendering->Wireframe) ans watch as you torture prims. You probably have to turn off ground, surface patch and sky (Advanced->Render Types) to see it clearly.

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Chaos Borkotron wrote:

What I'd like to know is why you'd need any more than 100 - 200 trinagles for a bed post. And why you are uploading the bed post and not just combining it up and pulling it in as 1 mesh. I've seen quite a few super high quality meshes that use 5 1024x1024 maps for a chair or a sofa. This is really bad practise and if I did this I'd loose my job (I'm a game level and environment designer irl). You should use 1 map for a 3 peice suite. If I was designing a set of furniture for an apartment (including bathroom, kitchen, living room, dining room, master bedroom etc) I'd use 1 or 2 1024 maps FOR THE ENTIRE COLLECTION!.

 

For furniture used inside depending on it's size you'd want the lowest and possibly the low LOD's to be 1 triangle (so there not visible) as you are unlikely to see the mesh from that far away.  We were given mesh to help make SL run faster and to help optimize the world a little (did you know all prim and sculpts are 1024 triangles, even the cube)

 

Also remember this: "A workman always blames his tools". I'm building an entire city in mesh, and everything works just as it should. infact sometimes the costs are lower than expected

Yes, I get that professional game designers find all this simple.

 

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Drongle McMahon wrote:

"Rule: All LODS need to have the same number of Necopots"

Now I am confused. I guess it all depends what viewer version people are using, but I thought that was the old rule. and that the new rule is that the lower LODs can have a subset of the Necopots in the high LOD, but they must each have the same name (
material attribute in <triangle> or <poly> tag
) as one of the high LOD Necopots. Was that reverted? Or is that error message from an older viewer?

hmm... maybe the rule is outdated. The rules change all the time and probably you are right. I remember that i have read about a change like that too some time ago...

Anyways i remember that the same message appeared recently with another model that apparently had only one material on all LOD's. I was not able to find out what was wrong in that case and unfortunately i did not pay too much attention to it. Now it may be that there is more behind it... 

So another reason why it would be nice to know in more detail why the importer rejects the file.

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Chaos Borkotron wrote:

For furniture used inside depending on it's size you'd want the lowest and possibly the low LOD's to be 1 triangle (so there not visible) as you are unlikely to see the mesh from that far away.  We were given mesh to help make SL run faster and to help optimize the world a little (did you know all prim and sculpts are 1024 triangles, even the cube)


Nobody seems to know (or care?)  that the smallest sculptmap you can make has only 16 faces (32 triangles) when using a sculptmap of size 8*8 pixels.

While the biggest possible sculptmap has 1024 faces (2048 triangles) with a not necessarily square sculptmap.

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Thanks Pamela :)

I am working on a sort of layman documentation for mesh in SL. It's really just a re-organization of the notes I've taken during beta and this whole long process. The problem is that things are still changing a bit with the code. There have been bugs fixed in one viewer that aren't in the main viewer for example. So, you have to use workarounds in one viewer that you don't need in another. And well, it would be confusing for the reader if you have 2 or 3 different instructions for the same process. I'm still trying to figure out how to deal with that part of it since I want it to be understandable for beginners.

 

Edit: As for your file problem, I'd really need to see the .blend file to be able to help since it seems a mystery from the description of the issue.

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There is a simple possible cause for getting a higher PE in the upload window that's happened to me a few times. For various reasons sometimes i'll make a copy of the model i'm working on and move it to a different layer .

Then when i'm exporting to Collada I forget to check the "Export selected only" . All looks well in the Upload preview window  and its only if I check the vertex count or notice the unexpected high PE that I realize I have done something wrong :)

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Drongle McMahon wrote:

"Rule: All LODS need to have the same number of Necopots"

Now I am confused. I guess it all depends what viewer version people are using, but I thought that was the old rule. and that the new rule is that the lower LODs can have a subset of the Necopots in the high LOD, but they must each have the same name (
material attribute in <triangle> or <poly> tag
) as one of the high LOD Necopots. Was that reverted? Or is that error message from an older viewer?

In my current experience, the LODs still have to have the same material ids listed in the high LOD when uploading on the main viewer. Although, I know it says it just needs to be a subset. It's the same with partial bone lists in rigged mesh. I believe officially you are supposed to be able to use a partial list, but you still need the essential 21 bones.

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Ashasekayi Ra wrote:

Thanks Pamela
:)

I am working on a sort of layman documentation for mesh in SL. It's really just a re-organization of the notes I've taken during beta and this whole long process. The problem is that things are still changing a bit with the code. There have been bugs fixed in one viewer that aren't in the main viewer for example. So, you have to use workarounds in one viewer that you don't need in another. And well, it would be confusing for the reader if you have 2 or 3 different instructions for the same process. I'm still trying to figure out how to deal with that part of it since I want it to be understandable for beginners.


It sounds like a huge, very complicated job! But so very needed, bless you for undertaking it. :-)  (And bless Gaia and any others who have undertaken to interpret this to the masses.)

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Aquila Kytori wrote:

Then when i'm exporting to Collada I forget to check the "Export selected only" . All looks well in the Upload preview window  and its only if I check the vertex count or notice the unexpected high PE that I realize I have done something wrong
:)

Thanks Aquila -- yes I have done that many times! :-)

 

 

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Pamela Galli wrote:

I got this error:

 
Screen shot 2011-12-05 at 11.54.06 PM.png

 

BTW, all the models had the same one material assigned. 

 

I've seen that infuriating X appear in the loader a few times when I know everything has only the one material assigned too... The green "ship it" appears when I load the highest LOD and then changes to that error as soon as I select files for any of the lower ones. After selecting all the LOD files, try hitting the "reset form" button - I found that flipped all the X's back to nice green checkmarks and I was once again invited to ship it :)

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