Hair mesh size!

[Liramaril]

Hi! Just wondering what the average 'land impact' of new, state of the art hair is nowadays

Or tricount, either or!

[Lucia Nightfire]

Most creators use excessive topology.

Most creators release hair that exceeds 100K triangles, even with simple short flat hair.

And many unnecessarily use either LOD starvation tactics to save pennies on the initial upload cost which would have been recouped by the first sale anyway or use the same triangles in Medium and/or Low LOD levels as High LOD triangles because of continuously circulated and incorrect fears that not doing this would cause hair to look like bad from a short camera distance away.

Project ArcTan cannot get here any sooner. That is, if LL actually puts their foot down and stops playing pat-a-cakes as it has been doing for years now.

[Cyrule Adder]

As Lucia stated... many of the developers do some complete BS with their creations, and tell users to simply bump up their graphical settings with almost no concideration to the massive performance impact that does under a typical render scene for a viewer. Then they will do things like use a single triangle at the lowest LOD setting to save money, and drop the LI.  This is because the foolish concept of "More polygons means higher quality. Despite the texture density not changing. I am willing to bet that most of the developers hadn't even heard of optimization. Because when a high polygon model has triangles less than the size of a pixel, that causes some extreme performance issues.

That being said, Land Impact isn't the measurement for avatar attachments. It's complexity. Which... the LL complexity calculations are very suspect. Ideally... hair shouldn't really be more than 2-4k triangles. And that is being extremely generous. To put this into perspective, typical Tripple A game made by a multi-million dollar company, with computer destroying graphics... usually only has about 25-30k triangles for the entire character.

 

And hair, including dense body covering fur, beards, long voluminous hair, Afros, and what have you rarely ever exceed 1k triangles in total. So that should be the sweet spot. 

If you are planning on making hair. I suggest learning how to make hair cards. Then along with the normal texture, manipulate vertex normals to further adjust how the light will interact with it. This is how you can achieve sub 1k hair and still look better than most of the hair you will find on the marketplace.

Edited August 14, 2020 by Cyrule Adder

[Kyrah Abattoir]

If we go strictly on a "triangle to screen space" sense, you should absolutely use no more than the head it will go on.

But then, our favourite head creators are not exactly shining examples of conservative triangle use either.

Edited August 14, 2020 by Kyrah Abattoir

[Lucia Nightfire]

I can count on one hand the number of creators that release detailed hair that uses 30k or less triangles.

Sadly, they do not release hair that often.

Sadly, many that use to release in the 30k - 50k triangle range a few years ago have thrown caution/care to the wind and are regularly releasing hair that is 100k - 300k triangles or more.

[ChinRey]

15 hours ago, Liramaril said:

Or tricount, either or!

I haven't really made any hairs myself since I'm not familiar with the design aspect of it. But I have been esperimenting a bit and also checked various existing hairs. I've yet to see an SL hairstyle that couldn't have been done with less than 25,000 tris fairly easily and most could even have bee done with less than 10,000. Multiply those numbers with ten and you're in the same ballpark as what we actually wee in SL.

That being said, I don't think it's fair to blame the hair designers for this misery, at least not entirely. Why should they bother optimising their builds when there's nothing in it for them?

 

13 hours ago, Lucia Nightfire said:

Project ArcTan cannot get here any sooner. That is, if LL actually puts their foot down and stops playing pat-a-cakes as it has been doing for years now.

It's about 12 years overdue by now.

I'm not convinced it will help though. ArcTan will only be effective if it is 100% focused on providing the most objective performance data possible, taking evert major factor into account. Any permanent compromises caused by poor decisions of the past or pressure from various people and groups who advocating "bonuses" for their own darlings will render it all but useless. It's to early to say though, we'll see.

[Cyrule Adder]

9 hours ago, ChinRey said:

I haven't really made any hairs myself since I'm not familiar with the design aspect of it. But I have been esperimenting a bit and also checked various existing hairs. I've yet to see an SL hairstyle that couldn't have been done with less than 25,000 tris fairly easily and most could even have bee done with less than 10,000. Multiply those numbers with ten and you're in the same ballpark as what we actually wee in SL.

Take a look at some AAA games, they have done more with less. As I mentioned, the trick is mostly in the textures, and manipulating the normals of the vertex (and not just relying on texture normals). And you can fake volume of strands like this. It's a trick we often use in the game industry (though I work in simulations... we do the same thing). In the picture below, the vertex of each leaf has been edited in such a way that the lighting hits it as it would a sphere. Which allows it to visually look like it has far more volume than original.

Hair is also not as complex as people makes it out. There are usually three lairs to most standard haircuts. The underlying lair that gives the primary volume. These are wide ribbons. Secondary shapes that helps breaks up the first and gives additional detail. The third is usually the detail lair. Additionally. For some tools, you can actually run an auto decimation on it. Which will do it's best to preserve the shape while reducing the overall polygonal count. There's even two freely avaliable. Blender, and Simplygon

And, you're right. There isn't really a benefit to the creator. Which is why it'll be nice when the recomputation of LI comes along.

Edited August 15, 2020 by Cyrule Adder

[ChinRey]

35 minutes ago, Cyrule Adder said:

In the picture below...

Oh no, don't get me started on trees again!

It's one of my pet peeves. A "standard visual cmplexity" tree like the one in your picture shouldn't be more than 300 tris at most of course yet it's not at all uncommon to see similar ones in SL with several thousand tris.

 

35 minutes ago, Cyrule Adder said:

Hair is also not as complex as people makes it out.

That may be true but hair styles are tricky for somebody with no fashion sense.

 

35 minutes ago, Cyrule Adder said:

Which is why it'll be nice when the recomputation of LI comes along.

If they get it right, yes. BUt that's a big if.

Edited August 15, 2020 by ChinRey

[Liramaril]

Thank you guys, all great info! 

I am making hair, but I decided to mesh it because I wasn't sure about hair-cards for curls? I will try hair cards next round when I do something shorter and less..intricate (I always pick the hard projects for some ridiculous reason lol)

I don't know how people can get upwards of 40k tri-count objects through the uploader? If I try to upload anything over 30k tris it tends to crap out on me! Then again, my topology is VERY messy...

I love that info on normals! That's rad!

My hair is currently at 27k tris, which since that's still too much I'm trying to cut down. I learn through fixing my own mistakes... which... well it can be the hard way XD

Edited August 17, 2020 by Liramaril

[Kyrah Abattoir]

Might be worth studying some actual game models too, SL content is just a bad reference point.