Will there ever be a fix for overlapping alphas?

[MelodyClone1]

...Or is this not possible in the current engine? Almost all good hairs contain alpha textures in at least some strands, and I'm sure pretty much everyone uses mesh heads and some makeup layers or clothing that has alphas. Simply masking some layers is just not possible considering 99% of things in SL are no mod for some annoying reason (whole other discussion). Also, right clicking on the attachment doesn't really fix the issue in most cases, not to mention it's only a client side fix even when it works. I have lots of hairs that go over my chest, would be great to not have my nipples completely visible when I'm wearing tops that has so much as 1% transparency or a lace texture. 🙄

[Vanity Fair]

My understanding of the issue is that it is technically impossible to fix this, but I don't know the technical details about why. Perhaps someone with a better knowledge than I can elucidate.

I just wear updos when I want to avoid the problem.

Edited December 2, 2019 by Vanity Fair

[Wulfie Reanimator]

While it is technically possible to fix, it's not very practical/efficient. It takes a lot of calculations to figure out which of many surfaces is in front of the others, and what order the rest of them are in. Most games make an attempt but to get it right in every situation is veeerry slow, so most games try to avoid using blended alpha surfaces.

Second Life has no quality control or standard for assets, so these kinds of technical concerns aren't thought about or worked around by almost anybody. Creators just accept it as a reality and leave it at that. 

Edited December 2, 2019 by Wulfie Reanimator

[animats]

4 hours ago, Vanity Fair said:

My understanding of the issue is that it is technically impossible to fix this, but I don't know the technical details about why. Perhaps someone with a better knowledge than I can elucidate.

The SL summary.

See this Wikipedia article for the theory.

The "over" operator is not commutative. So the order in which the objects are drawn matters. The viewer has to sort alpha-blend faces by depth, using the main CPU, not the GPU. Faces, not pixels. Faces which intersect faces in the look direction have an "who's in front" ambiguity. This is why things like crossed signs get mis-drawn when alpha blended. If you use alpha blending, the faces involved should not cross through each other.

Regular opaque and alpha masked objects get sorted out pixel by pixel in the GPU, by storing their "depth' (distance from the viewpoint) in a "Z buffer". The pixel with the smallest Z-buffer value wins. GPUs do all that with built-in hardware, so that's cheap. That gets 'who's in front" right on a per-pixel basis, so it doesn't have the see-through problem.

If you want skin-tight clothing, there's always old-fashioned texture clothing, which is really just a paint job. But you can get translucency right, since that happens when you composite the texture images on top of each other in 2D.

[Kyrah Abattoir]

On 12/2/2019 at 7:39 PM, MelodyClone1 said:

...Or is this not possible in the current engine? Almost all good hairs contain alpha textures in at least some strands, and I'm sure pretty much everyone uses mesh heads and some makeup layers or clothing that has alphas. Simply masking some layers is just not possible considering 99% of things in SL are no mod for some annoying reason (whole other discussion). Also, right clicking on the attachment doesn't really fix the issue in most cases, not to mention it's only a client side fix even when it works. I have lots of hairs that go over my chest, would be great to not have my nipples completely visible when I'm wearing tops that has so much as 1% transparency or a lace texture. 🙄

Good hair creators don't abuse alpha layering and use alpha masking as much as they can. Bad creators claim it's SL's fault.

Good creators do the best they can within the limitations of the system. Bad creators complain that the limitations exist.

[MelodyClone1]

On 12/16/2019 at 5:36 PM, Kyrah Abattoir said:

Good hair creators don't abuse alpha layering and use alpha masking as much as they can. Bad creators claim it's SL's fault.

Good creators do the best they can within the limitations of the system. Bad creators complain that the limitations exist.

Not really the creator's fault when alpha masking on hair looks ugly af. I have never seen a single hair strand that looks good with alpha masking, it all turns them into hair you'd see in something like Morrowind.

[Wulfie Reanimator]

26 minutes ago, MelodyClone1 said:

Not really the creator's fault when alpha masking on hair looks ugly af. I have never seen a single hair strand that looks good with alpha masking, it all turns them into hair you'd see in something like Morrowind.

That's because making alpha-masking hair textures require a different technique instead of the finely feathered strands you've seen. Using alpha-masking on blended textures is guaranteed to be a bad time. You can get very good looking hair with masking, comparing to Morrowind is ridiculous. 

Edited December 24, 2019 by Wulfie Reanimator

[Kyrah Abattoir]

On 12/24/2019 at 4:58 PM, MelodyClone1 said:

Not really the creator's fault when alpha masking on hair looks ugly af. I have never seen a single hair strand that looks good with alpha masking, it all turns them into hair you'd see in something like Morrowind.

"The bad workman blame his tools."

Hair making is picked up by a lot of people who just picked up modeling, because "layering alpha" strands is a pretty forgiving process and there is a lot of dodgy tutorials out there for it, if you compare what your average hair creator does in SL, to what is used in games, it's basically night and day.

Alpha sorting is nothing new in video games, you had to deal with it for as long as I can remember. It is pretty much a "solved" issue unless you insist on ignoring how the professionals deal with it.

[MaxMare]

I saw Magika advertising their hairstyles no longer cause alpha glitching, can`t say I tested it, but I do trust that brand so they must have found a solution and I really wish I knew how they did it...

btw I`m not a fan of alpha hair in general, most styles look great in front view, but if you check from a side, there is no volume, just several slices of folded paper hanging over your boobs..then there is this trend with sheer or fishnet/lace clothing which is both horrible and dysfunctional, but then again, I see some bigger brands actually modeling lace or fishnet and I can only imagine sheer amount of geometry that took which is even worse then glitchy alpha option...

at least BoM resolved issues with applier clothes, tattoos and make up (except lashes), perhaps you need your meshes (head and body) updated to BoM version and give it a try?