Materials vs. LI

[Six Igaly]

I played with some freebie material textures and I really like it. But is it useful? That, so I noticed, is totally depending on where and how it is used. What I discovered just now is this. I had a sphere rezzed, 18 m in size, hollowed and I used dimple on both ends. Then I used material textures and this gave the LI a boost. It went up from 1 to 31 just like that! Of course I can reason that all, it is just not something I was expecting. So if you noticed your prim usage is way to high and you can't figure it out, maybe you did something similar. Just saying.

[Six Igaly]

I played with some freebie material textures and I really like it. But is it useful? That, so I noticed, is totally depending on where and how it is used. What I discovered just now is this. I had a sphere rezzed, 18 m in size, hollowed and I used dimple on both ends. Then I used material textures and this gave the LI a boost. It went up from 1 to 31 just like that! Of course I can reason that all, it is just not something I was expecting. So if you noticed your prim usage is way to high and you can't figure it out, maybe you did something similar. Just saying.

[IvanBenjammin]

I believe that when you use materials on prims, you force them to use 'true' land-impact values. I'm not 100% sure on this as everything I make is mesh, but I think its mostly physics weight that is driving the LI up.

I found this with a quick google search: https://jira.secondlife.com/browse/MATBUG-277

 

 

[Rhys Goode]

I've played around a bit "torturing" prims, switching the physics shape type between convex hull and prim, and can easily boost the LI from a single prim from 1 to 250, at least with a tortured torus. I am a bit suprised that a dimple on a sphere has this drastic an impact, but only a little.  Mesh has so much less impact, I sometimes wonder at the fact that they grandfathered in the prims. I guess its a trade off between accessablitly and efficiency.

[Cerise Sorbet]

Yeah, materials switches on new style LI. It's not as wacky as it seems; the idea is to let old content work as it always did, but use the presence of new features to identify new/newly modified work that should play by the updated rules. Rez or creation date would have thrown in too many false positives and false negatives.

Concave shapes make the physics engine cry, so dimpling, hollowing, etc. are just reflecting that. The convex hull gives Havok permission to ignore those headaches, and "none" on child prims is Havok's get out of jail free card, so we get rewarded for using them.

 

[Kwakkelde Kwak]

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Rhys Goode wrote:

I am a bit suprised that a dimple on a sphere has this drastic an impact, but only a little.

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The dimple has such a big effect because the havoc engine recognizes a sphere as "a sphere", it's the same for a box and cylinder. As soon as you hollow, dimple, twist or alter the shape in any other way, the object is no longer a mathematical sphere, box or cylinder. The result is that the engine triangulates the physical shape. So instead of one physical entity, you end up with a couple of hundred, some very small. That has a big impact on the calculation.