Blinking Alphas

Howdy all, I just created some curtains TGA 32bit but after adding to my windows they blink, or in other words disapear and apear again........only happens on certain angle positions from where I stand...

Any ideas why thats happening?

This sounds like the alpha sorting glitch which happens when you have two prims with 32 bit textures overlapping in your line of sight. There is no way for the system to know which should be "in front" and so you get this flicker. There is no way to fix it. The best approach is to use alpha transparency textures sparingingly. I am assuming you have a semi transparent fabric or lacy edge on your curtains and that is why you chose the 32 bit tga. You can experiement with rearranging or redesigning so you don't have the prims so close together.

Yup, definitely the alpha sorting glitch. So you know, it's common to just about all 3D applications. It's not just an SL thing. As Sylvia said, the solution is to make sure you only use 32-bit textures where absolutely necessary. Build around the problem since there's no way actually to solve it.

I'd suggest you incorporate your curtains directly into your window texture, so the whole thing is on one surface.

My my, hmm....I will figure something out........I think the worsest scenario is to make walls with holes in them and not walls with 32bit alphas for windows......

There are two good solutions:

1: Integrate the curtains with the window texture itself. You can use a script to switch between a texture that shows them open and a texture that shows them closed. Limiting factor is that you need the skill to make the custom textures, skill with scripting, and the curtains can't overlap the surrounding wall - they stay within the window frame. Unless the whole wall is a single texture,m in which case you can again have one texture with curtains open, and one with them closed, and use a script to swap states. (I make and sell textures like these, with the curtains open and closed, but anyone can make them if you try.)

2: Use prim curtains that do NOT use a 32-but texture. It is possible to script a prim to change size on command, so a cube prim can go from a narrow column on either side of the window to being two flat planes covering the window, and can also change the texture from tight pleats in fabric to loose pleats. Again, requires scripting and texture know how, but looks quite good in some cases. (Starchaser Webb scripted a set of prim curtains that I use in a bunch of my builds.)

Anything transparent will have this effect, be it a window, a wall with a texture hole (Instead of a hollow prim ), or anything of that sort.

The transparency itself seems to cause the texture to gain an alpha channel even if its a 24 bit texture.

If you put two prims, blank texture, overlapping, and make both transparent, they will alternate between which shows as front because it doesnt know how to sort it properly.

Most of the time the way around this is use more prims, and less alphas. A whole wall being see through like that is a lot worse than say, just a window.

EDITED:: Edited to appease the forum god that is almighty Chosen Few

Quite true. If you texture a prim with opaque 24-bit textures, but then use the texture tab editing features to tell Sl that one or more faces are to be anything other than 100% opacity, then SL treats that semi-transparent face the same as any other alpha texture for rendering purposes.

Grrr

sorry!

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I did solve the problem, by integrating the curtains with the wall/windows alpha texture....looks quite nice and worked well........

My client requested privacy windows and the only way I see this will work for them is by making the exterior wall/windows non-alpha, while the interior wall/windows you can see outside from inside.

I do like the idea of scripted curtains to open and close....or even mini-blinds....if I do get my hands on a script like that I may experiment that style.

For the meantime, the problem is solved.

Thanks all for the tips!

If you have enough prims to spend on this, make the wall and the window separate prims. You can turn the wall prim so that the Z axis points in / out of the room and hollow it to make the opening for the window.

I use sets of window textures from Ceera Murakami which have curtains in various states of closed, open or not there at all, for inside and outside the house. I also use window textures by Gatz Morang which have blinds rather than curtains.

To start with, you can simply put a closed window or blind texture on the outside of the window and an open one on the inside. However if you script the windows to change on command, it adds an extra wow factor to the house.

I currently have this in my Home, a simple controller with unlinked curtains in the windows, I'm willing to share the scripting with anyone who wants it. Works region-wide.

Two words... particle curtains.

How many curtains could you manage before most people were unable to render more particles?

Hell, 4096 isnt even that many... XD

Saving prims is a must on this assignment and really need to keep prims dowm...I really saved prims by embedding the curtains along with walls/windows alphas. I achieved privacy with mini-blinds between inner/outer wall that works with a controller.

The other way I can think of is a texture switcher....that switches between an alpha texture and a non alpha texture to emmulate closed curtains.......

The most basic and economical manner is to have exterior windows non-alpha while interior windows with alpha, that way no one can see in from outside while people inside can see to the outside.

Its a fancy feature, but still people can move their cameras into homes and see whats going on inside and even teleport there, but there are security measures that one can use to deter intruders or even scan nearby cameras from other avatars......