Discussing fashion with Debi, Jasmine, and some others, Debi had a cool idea about how to deal with limiting avatar complexity. I dub it a "trigon budget". The idea would be that each attachment would indicate how many trigons it has when worn. As you add attachments, you would see how many total trigons are used. If you exceed a fixed budget of trigons (e.g., 5 x 8k = 40k), you simply cannot save your avatar in Lookbook.

One benefit of this is that you could increase the number (unlimited?) of attachments allowed.

This could seem to add complexity, because now people have to think a little extra about their budget, but this would also encourage designers to improve their own trigon budgeting skills.

This budget could also apply to the avatar's main shape, too.

Thoughts?

• Gindipple

Why not just call it a triangle budget?

Since a trigon isn't really a word.

Also I don't think they are limiting the number of attachments specifically to limit triangles, but more so it's a limit on what they have coded up in the rigging process.

Triangle count limits I would imagine are not completely for performance, but somewhat just to prevent insane use cases.

This is quite similar to the cluster rez rate currently imposed, we know the system can handle it faster, but they imposed a limit to prevent crazy cases...

Otherwise the idea is fair I suppose.

They've told us in the fashion meetings that is was to reduce complexity and that they started out very conservative because it's easier to relax than to reign back in polys.

• Galen

"Trigon" is actually an archaic word that means "triangle". I didn't make it up. The term is starting to come into vogue in 3D graphics programs because it connotes a narrower concept. Whereas a program like Blender will let you define multi-edged polygons and show you the polygon count for them, a graphics card will reduce polygons down to discrete triangle portions for computational performance and planar disambiguation reasons. Sansar requires trigons, too.

A trigon in this usage specifically refers to that smallest unit of representation of a mesh surface used by a modern video card. A triangle more broadly represents the abstract shape we all know and love. Yet an actual triangle in a scene might actually be composed of thousands of trigons. And a triangle may have two sides, typically represented by two trigons.

Thus, "trigon" is more precise a term and measurement unit than "triangle".

Edited by Galen
• Galen

The reason LL puts trigon limits on meshes is because it is very easy for designers to be lazy and lavish. If you want a really beautiful complex mesh, the easiest way is to compose it of thousands or even millions of trigons. The problem is that each trigon consumes memory in the video card and requires its own discrete draw call to compose each rendered frame. The number of trigons is thus the primary cost unit for rendering 3D scenes and should be kept as small as reasonably possible.

To put some perspective on why the limits matter, consider the current budget. If I'm not mistaken, an avatar may have up to 5 clothing attachments and up to 5 accessories attachments. If each one of those has a limit of 8k trigons, then each avatar can have up to 80,000 trigons in attachments, alone. I don't know what the trigon count on the base avatars and hair meshes are. But let's say there are 30 avatars in a single scene. That adds up to 2.4 million trigons just for avatar attachments. Every one of those trigons must be stored in video card memory (no big deal) and drawn in each video frame (big deal!).

Since trigon count is the primary unit of mesh representation and governor of rendering frame-rate, you can see why LL is anxious to put a per-avatar cap on trigon count for each avatar. All I've pitched is the idea of making it a collective budget for each avatar that users can "spend" as they choose. Roughly speaking, one trigon costs as much as another.

Edited by Galen
• Gindipple

Thus, "trigon" is more precise a term and measurement unit than "triangle".

So all the mathematicians and graphics card designers are all less precise than you.

Noted.

Yet an actual triangle in a scene might actually be composed of thousands of trigons.

What kind of drugs are you on?

Acid? LSD?

• Gindipple

Trigon is such a precise word that Wolfram Math research even has a page for it.

http://mathworld.wolfram.com/Trigon.html

:-)

Q.E.D.

• Cora

I like this idea. It would allow for more mixing and matching in Lookbook without necessarily increasing the overall avatar tri budget. Currently, the slot system encourages creators to combine as much as possible into one immutable 8k outfit.

If a creator makes a super optimized 1k clothing item, it shouldn't have to take up an entire 8k clothing slot. It would encourage more optimization.

• Luise

It is a good idea and a solution to the 4 garments restriction.

About the trigon: it is a Greek word. It is a combination of two words, tris and gonies. It means three angles ( triangle) and is used in the determination of the geometric shape having three angles.