Transparent avatars

[Myrdinn]

Hello SL Experts. Why i see some avatars partially transparent but when i rotate my camera i see them normally?

http://i43.tinypic.com/25guq6r.jpg

[Reg Halostar]

That can happen if you deactivate the "Basic Shaders" in Preferences - Graphics. I can't say why but it is an observation on several ATI graphic cards. If you change the position of the camera the skin of the avatars appears or disappears - the prim attachment remain visible though...

[Myrdinn]

Thanks for your answer Reg, but i have Basic Shaders enabled and i use Nvidia.

[Chosen Few]

Occlusion culling issue, maybe?  I only thought of it, because you said the problem goes away when you rotate the camera.  Try turning off object-object occlusion, and see if that solves it.

It could also be a driver problem, of course.  How recent is your graphics driver, and was it properly installed?  (Properly installed means completely uninstall the old one before installing the new one, and never letting Windows Update touch your drivers in any way, shape, or form.)

[Sy Beck]

Ask them if they are wearing mesh clothes.  If you are not using a mesh enabled viewer then mesh clothes usually deform to a sculpt shape, but I have noticed when I'm wearing mesh clothes or swapping them around then the alpha layers can get glitchy and I end up looking like the people in your pic.

[Chosen Few]

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Sy Beck wrote:

alpha layers

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Alpha what?

[Myrdinn]

How i can turn off object-object occlusion?  If you mean Ambient Occlusion i have this option disabled.

For Sy: I use Viewer 3.2.1

[valerie Inshan]

Since version 2.0, alpha layers have replaced the invisiprims:

Note: The new alpha layer feature of Viewer 2.0 has replaced the use of invisiprims to hide parts of the avatar.

http://wiki.secondlife.com/wiki/Invisiprim

[Chosen Few]

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Myrdinn wrote:

How i can turn off object-object occlusion?

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1.  Press ctrl-alt-D to enable the Advanced menu.

2.  Press ctrl-alt-Q to aneable the Develop menu

3.  Click Develop -> Rendering -> Object-Object Occlusion (or use the shortcut, ctrl-shift-O)

 

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Myrdinn wrote:

If you mean Ambient Occlusion i have this option disabled.

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Entirely different thing. 

Ambient Occlusion is a lighting/shading effect, which simulates the RL way in which ambient light is occluded by surfaces that are in close proximity to each other.  Notice the edges of an interior wall in RL are generally darker than the middle of the wall, since less light can escape out of the corners than the middle.

Object-object occlusion, or occlusion culling, as it's called on some other platforms, is a process by which the renderer makes decisions about what objects to include in the drawing of each frame.  When one object is in front of another, thereby occluding it from view, the renderer is free not to draw the one that can't be seen.  This will speed up the actual drawing process, thereby increasing FPS. 

But there's a catch.  It first has to run a check on each and every object, to determine what's in front of what, which can sometimes slow down FPS.  So it's often a 'six of one, half a dozen of the other' type of situation.  SL tries to get around that potential problem by not running the check on every frame.  It checks once, and then refrains from rechecking again until and unless the the camera turns, or the contents of the scene change substantially. 

That was why I thought of object-object occlusion as your potential culprit.  If objects seem to pop in and out of existence in response camera rotation, an error in occlusion culling can often be to blame.

[Chosen Few]

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valerie Inshan wrote:

Since version 2.0, alpha layers have replaced the invisiprims:

Note: The new alpha layer feature of

Viewer 2.0

has replaced the use of invisiprims to hide parts of the avatar.

http://wiki.secondlife.com/wiki/Invisiprim

---

Thanks, Valerie, but I'm afraid you misunderstood my comment, and repeated my reason for having made it in the first place.  There's no such thing as a "alpha layer".  It's an alpha CHANNEL (or an alpha mask, depending on context).  Layers and channels are entirely different things.  These forums are the only place in the known universe where people insist upon using the two words interchangeably.  It's super confusing for newbies, and it's my single biggest petpeave on the forums.

Now I see the error in terminology also has unfortunately made its way to the wiki, presumably as a consequence of the fact that a lot of the same people who write forum posts write wiki articles.  Thanks for bringing that to my attention.  I'm going through and correcting it now, where I can.

[Myrdinn]

THanks for your explanation Chosen. I will try that.

[Kelli May]

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Chosen Few wrote:

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valerie Inshan wrote:

Since version 2.0, alpha layers have replaced the invisiprims:

Note: The new alpha layer feature of

Viewer 2.0

has replaced the use of invisiprims to hide parts of the avatar.

http://wiki.secondlife.com/wiki/Invisiprim

---

Thanks, Valerie, but I'm afraid you misunderstood my comment, and repeated my reason for having made it in the first place.  There's no such thing as a "alpha layer".  It's an alpha CHANNEL (or an alpha mask, depending on context).  Layers and channels are entirely different things.  These forums are the only place in the known universe where people insist upon using the two words interchangeably.  It's super confusing for newbies, and it's my single biggest petpeave on the forums.

Now I see the error in terminology also has unfortunately made its way to the wiki, presumably as a consequence of the fact that a lot of the same people who write forum posts write wiki articles.  Thanks for bringing that to my attention.  I'm going through and correcting it now, where I can.

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The reason for this difference in terminology is because the various parts of an avatar are commonly (but maybe not accurately) referred to as layers: skin layers, clothing layers, and more recently alpha, tattoo and (I suppose) physics layers. The alpha 'layer' is actually composed of 5 separate mask textures. So generally, SLers aren't talking about an alpha channel/mask as it would appear in image-processing, but the mask(s) as applied to the 'alpha layer' of their avatar.

eta: I'm not sure if LL have an official term for what we call 'layers' but physics are sometimes called 'wearables' and all apart from skin are created as 'clothes'.

[Myrdinn]

Well the problem fixed when i disabled Object-Object occlusion. Thanks so much Chosen!

[Chosen Few]

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Kelli May wrote:

The reason for this difference in terminology is because the various parts of an avatar are commonly (but maybe not accurately) referred to as layers: skin layers, clothing layers, and more recently alpha, tattoo

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Interesting stab at a theory, but from the history, I very much doubt that the fact that avatar outfits are composited from layers (just like any other image composite) has anything to do with this directly.  People on the SL forums have routinely tried to synonymize the words "layer" and "channel" in contexts that have had nothing to do with clothing or skinning the avatar, for at least the last seven or eight years now.

Most likely, it began with a badly worded tutorial very early on, and just self-perpetuated from there, in much the same way that certain other lingering misconceptions about content creation have taken on a life of their own.  The dispelling of such myths has been an ongoing topic of discussion on the building and texturing forums for as long as I can remember, going all the way back to January of '04, when I first took up the cause, myself.

I've written entire articles on the subject over the years, and I continue to try to squash these errors whenever they pop up.

 

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Kelli May wrote:

physics layers.

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I have no idea what a "physics layer" might be.  Care to elaborate?  Physics has nothing to do with texturing at all.

 

 

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Kelli May wrote:

The alpha 'layer' is actually composed of 5 separate mask textures.

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Yes, it's five individual masks, but that's only because the avatar body is broken geographically into five sections. Each mask corresponds to one region. They do not get stacked on top of each other as layers. They don't even constitute one layer, let alone five.

 

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Kelli May wrote:

So generally, SLers aren't talking about an alpha channel/mask as it would appear in image-processing, but the mask(s) as applied to the 'alpha layer' of their avatar.

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Oh, I'm well aware of what people think they're talking about.  But that's precisely my point. Why should we let ignorance and misunderstanding linger, when we can so easily put people on a path to proper education on what the terms actually mean?

There is no "alpha layer of the avatar". There's no "alpha layer" of anything at all, because there's just no such thing as an "alpha layer", period.  It it were a layer, it would be composited in the stack, just like all the others, and you'd see the blacks and whites and grays of it as colors, rather as transparency, since the only part of the avatar shader that supports layers is the diffuse color channel.

When they added the alpha mask feature to the avatar, they simply added a transparency channel to the shader.  The alpha map images that we apply to the mask slots in the appearance editor just serve as data maps to govern the vualues of transparency channel, per texel.  The channel itself does not support layering in any way, shape, or form.  Thus the very word "layer" is entirely foreign in this context.

 

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Kelli May wrote:

eta: I'm not sure if LL have an official term for what we call 'layers' but physics are sometimes called 'wearables' and all apart from skin are created as 'clothes'.

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I'm not sure what you mean by "physics are sometimes called wearables".  Physics are forces, like gravity, wind, friction, etc., and the properties objects possess that dictate how they respond to such forces, like weight, solidity, rigidity, etc.  A ball rolls down hill because of physics.  Your avatar can stand on a cube because of physics.  None of that has anything to do with textures or with anything your avatar might be wearing.

Did you perhaps mean to say, "attachments are sometimes called 'wearables'"?

 

As for the layers of the avatar outfit itself (skin and clothing layers), those are properly called layers.

[Chosen Few]

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Myrdinn wrote:

Well the problem fixed when i disabled Object-Object occlusion. Thanks so much Chosen!

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Glad to hear you got it sorted (no pun intended).  I might suggest updating your graphics driver, and then try re-enabling it.  It coud just be that your current driver doesn't like SL's mathematics for its OOO calculations.

[Kelli May]

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Chosen Few wrote:

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Kelli May wrote:

The reason for this difference in terminology is because the various parts of an avatar are commonly (but maybe not accurately) referred to as layers: skin layers, clothing layers, and more recently alpha, tattoo

---

Interesting stab at a theory, but from the history, I very much doubt that the fact that avatar outfits are composited from layers (just like any other image composite) has anything to do with this directly.  People on the SL forums have routinely tried to synonymize the words "layer" and "channel" in contexts that have had nothing to do with clothing or skinning the avatar, for at least the last seven or eight years now.

Most likely, it began with a badly worded tutorial very early on, and just self-perpetuated from there, in much the same way that certain other lingering misconceptions about content creation have taken on a life of their own.  The dispelling of such myths has been an ongoing topic of discussion on the building and texturing forums for as long as I can remember, going all the way back to January of '04, when I first took up the cause, myself.

I've written entire articles on the subject over the years, and I continue to try to squash these errors whenever they pop up.

Interesting theory? I'd call it more an observation: most of the people of talked to in SL, and on these forums, routinely refer to the clothing (non-prim, non-mesh), skins, tattoos and other parts of their avatar as layers. They might not be technically right to do so, but that doesn't stop it being common practice. I don't plan to argue about this -  you are clearly well aware of the difference between the technical terminology and the day-to-day usage.

 

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Kelli May wrote:

physics layers.

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I have no idea what a "physics layer" might be.  Care to elaborate?  Physics has nothing to do with texturing at all.

What I'm referring to are the pseudo-physics visual effects which create the apprearence of movement in an avatar's breasts, buttocks and stomach in more recent viewers. As I don't use the official LL viewer, my experience here might be totally biased toward my third-party viewer experience. If you choose to add these effects to your avatar (in Phoenix, at least) you create a 'layer' (note quotes, I realise it's not a real layer), either through the Inventory or Edit Appearence. 

You're absolutely correct that it has nothing to do with texturing, but for some reason avatar physics is lumped in with clothing in the viewers I've used. I think it's a pretty stupid idea too.

 

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Kelli May wrote:

The alpha 'layer' is actually composed of 5 separate mask textures.

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Yes, it's five individual masks, but that's only because the avatar body is broken geographically into five sections. Each mask corresponds to one region. They do not get stacked on top of each other as layers. They don't even constitute one layer, let alone five.

 

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Kelli May wrote:

So generally, SLers aren't talking about an alpha channel/mask as it would appear in image-processing, but the mask(s) as applied to the 'alpha layer' of their avatar.

---

Oh, I'm well aware of what people think they're talking about.  But that's precisely my point. Why should we let ignorance and misunderstanding linger, when we can so easily put people on a path to proper education on what the terms actually mean?

There is no "alpha layer of the avatar". There's no "alpha layer" of anything at all, because there's just no such thing as an "alpha layer", period.  It it were a layer, it would be composited in the stack, just like all the others, and you'd see the blacks and whites and grays of it as colors, rather as transparency, since the only part of the avatar shader that supports layers is the diffuse color channel.

When they added the alpha mask feature to the avatar, they simply added a transparency channel to the shader.  The alpha map images that we apply to the mask slots in the appearance editor just serve as data maps to govern the vualues of transparency channel, per texel.  The channel itself does not support layering in any way, shape, or form.  Thus the very word "layer" is entirely foreign in this context.

 

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Kelli May wrote:

eta: I'm not sure if LL have an official term for what we call 'layers' but physics are sometimes called 'wearables' and all apart from skin are created as 'clothes'.

---

I'm not sure what you mean by "physics are sometimes called wearables".  Physics are forces, like gravity, wind, friction, etc., and the properties objects possess that dictate how they respond to such forces, like weight, solidity, rigidity, etc.  A ball rolls down hill because of physics.  Your avatar can stand on a cube because of physics.  None of that has anything to do with textures or with anything your avatar might be wearing.

Did you perhaps mean to say, "attachments are sometimes called 'wearables'"?

Referring back to your previous mention of physics, I think I've answered what I meant. As for the 'wearables' question: I was referring to the Appearence Editor which states, under the Physics tab, "Put on a new physics wearable by dragging one from your inventory to your avatar". Again, the only evidence I have is from the Phoenix viewer, but that does mean that the statement "physics are sometimes called wearables" is perfectly true, even if it only applies to the designers of that version of the viewer. So no, I wasn't mistakenly referring to attachments.

 

As for the layers of the avatar outfit itself (skin and clothing layers), those are properly called layers.

And hence comes the difficulty. Viewers group alphas and 'physics' in with clothing and skins. In the very same menus as clothing, one finds tabs for 'create new alpha' and 'create new physics'.  Even though they aren't necessarily layers (alpha), or even related to textures (physics), that's where one finds them. Is it at all surprising that they get called layers?

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[Chosen Few]

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Kelli May wrote:

most of the people of talked to in SL, and on these forums, routinely refer to the clothing (non-prim, non-mesh), skins, tattoos and other parts of their avatar as layers.

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Sure, because that's what they are. But that says nothing about what is or isn't the root cause for the misnomer, "alpha layer". People routinely refer to the nonsensical "alpha layer' when discussing imagery that has absolutely nothing to do with the avatar. If it were limited merely to discussions of the avatar and its parts, I wouldn't be so concerned.

I've made enough of a point of harping on it for the past eight years that the mistake is nowhere near as common as it used to be on the building and texturing forums. People are fully capable of learning, when presented with the proper information, after all. But still, the error does pop up with annoying frequency.

 

 

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Kelli May wrote:

They might not be technically right to do so, but that doesn't stop it being common practice.

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They're perfectly right to refer to the clothing and skin layers as layers. No one is right to use the term "alpha layer", however.

 

 

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Kelli May wrote:

I don't plan to argue about this

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And yet you seem to be, for reasons I don't pretend to understand.  Can't we just agree that no matter what the cause for a mistake, it's a good idea to correct it when encountered?

 

 

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Kelli May wrote:

you are clearly well aware of the difference between the technical terminology and the day-to-day usage.

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And that's precisely my point. The day-to-day usage and the technical terminology should be identical. They ARE identical everywhere else in the world except for this forum. The fact that certain people insist on making up their own terminology in their various writings, rather than embrace that which already exists, is highly detrimental to the learning process for anyone who's new to this. As an author and a teacher of these topics, I see the damage first hand all the time. I don't understand why you appear to be implying that striving to prevent that problem is somehow a bad idea.

 

 

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Kelli May wrote:

What I'm referring to are the pseudo-physics visual effects which create the apprearence of movement in an avatar's breasts, buttocks and stomach in more recent viewers. As I don't use the official LL viewer, my experience here might be totally biased toward my third-party viewer experience. If you choose to add these effects to your avatar (in Phoenix, at least) you create a 'layer' (note quotes, I realise it's not a real layer), either through the Inventory or Edit Appearence. You're absolutely correct that it has nothing to do with texturing, but for some reason avatar physics is lumped in with clothing in the viewers I've used. I think it's a pretty stupid idea too.

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Ah, thanks for clarifying. Never having used any TPV myself, I had no idea that that was the terminology being used in any of them.

 

 

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Kelli May wrote:

And hence comes the difficulty. Viewers group alphas and 'physics' in with clothing and skins. In the very same menus as clothing, one finds tabs for 'create new alpha' and 'create new physics'. Even though they aren't necessarily layers (alpha), or even related to textures (physics), that's where one finds them. Is it at all surprising that they get called layers?

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I won't deny the possibility that for some, the pattern of confusion might go as you suggest. But I can promise you, the misnomer started here long before those features existed, years before there was even any such thing as a third party viewer.

In any case, you seem to be implying we should just accept the incorrect, rather than seek to improve it. I'd much rather educate whenever possible. The more the general public understands, and the more everyone can speak the same language intelligently, the better off we all inevitably are.