Prim Bonuses and LODs

[ChinRey]

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Drongle McMahon wrote:

I guess I wasn't clear enough. The sculpty physics shape is the convex hull of the low LOD torus, not the torus itself.

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Oh, I misunderstood you then. I thought the two physics shapes on your picture showed the two sides of the sculpt physics. 2.1 sounds about right for a convex hull of that shape. 1.8 physics weight sounds about right for a hull of that complexity. Still doesn't explain why they chose a shape as complex at all though. Might be because sculpts predate Havok and they didn't want to change the original sculpt physics shape.

[Drongle McMahon]

I think the shape was chosen because they wanted something vaguely round, but with flattened endss so that it could stand stably in one orientation. Sculpts were originally intended for "organic" shapes, by which was meant something blob like, rocks, apples etc.

[ChinRey]

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Drongle McMahon wrote:

...

rocks, apples etc.

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Do not confuse rocks with apples, it's bad for your teeth! At least that's what my mum told me.

[Drongle McMahon]

Well. I finally wrote my script to do a specified (to power of two) rounding of vertex positions, normals, and/or UV cooordinates, in a collada file. The idea was to avoid vertex splitting cause by "wobble" as well as possibly correcting small misalignments. It worked as expected as far as the vertex count of the high LOD was concerned, but a very odd problem appeared with the basket-like table model we were using. After some applications, with particulat rounding stringencies, the resulting collada files couldn't be processed by GLOD. The vertex county stopped getting reduced after one or two steps, ending up with very high download weights. Now this model is rather like the cases we have discussed here before where toroidal geometry blocks GLOD. However, it is very surprising to me that simply changing the precision of the data can affect whether we see this behaviour or not. Some further investigation is warranted, I think, before I can recommend this approach.

In practice, for this model using GLOD for a model using the bevel+transferred normals method to get rounded edges is completely useless anyway, because the normals, and so the shading, of the resulting mesh is badly messed up. In that sense, the GLOD sticking problem doesn't matter because you have to make LODs manually anyway.

[Codex Alpha]

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ChinRey wrote:

All I know is that you get higher LI if you don't keep your vertices straight.

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Interesting. I truly love real, practical information. Much appreciated. Kudos to Artu and Drongle as well.

My strategy lately is to upload my LOD1 mesh in SL, and see what the vertice requirements I should meet for the next LOD down, and work to meet them in the most efficient means possible.. then enter that model in .. then work on the next, upload that... using the uploader as a preview to see how it all goes. All the way down to LOD4.

That, and following the tips posted on this forum demonstrated on a simple pillow (didn't even know there was a check UVs, etc button before), I"ve already improved my LODS on every new product so far.

So thanks. Real practical advice with simple examples goes a long way for those of us who want to optimize and follow best practices, not only for our own piece of mind, but the success of SL in general.

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shaniqua Sahara wrote:

we have to accept poorly optimized things because it's part of the average.

i say turn up your LOD settings to where you can, make what you like how you like and go to town. eventually some will get better at it and others won't. that's sLife. we're all different sorts and stripes in it together whether we like it or not.

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I disagree. We should always design for the beginner SL'er, the average, and what looks good in the default settings of the viewer, and better than that.

I just bought some items from the MP from a seller who uses this excuse "Improve your LOD settings", but her stuff breaks LOD way too easily, and I'm on the default setting, and always have been. If anything I will lower it as has been suggested to see any weaknesses in my own meshes - and I strive to improve them, updating already a few products that had issues I was unaware of.

Accepting mediocrity is not the answer. Educating creators, and not supporting creators who don't go the extra mile is a better answer.