Problem with Window texture

Hi there -

based on a lot of topics here, I managed to create window textures for my building.
Everything looks pretty nice at first view, but there is a strange "effect" and I really don't know, how to get rid of it.

Description:
I have two pieces of wall (6x6x1m) textured with a plaster-like texture for the wall effect. Between those wall blocks I have another block (6x6x1m) for the window. The texture of the window block uses the same "background" for the wall effect plus a window picture with transparent areas. I put the texture on the block, the window is there and the small glass parts are fully transparent while the rest of the block is fully visible.
Seems to be ok, hm?

But - when someone is standing on the opposite side of the window block, I can see his name tag through the actually solid parts of the window block, but not the AV. In fact, the whole block seems to be transparent as well, however the wall structure (everything around the window frame) is visible as wanted.

I played around with Photoshop, re-created the texture several times by trying different techniques, but couldn't get it managed, that everything is "truely solid" except the glass parts.

I have searched the forums already, but couldn't find any helpful things yet.
Maybe one of you would be so kind and give a small hint?

As soon as SL is back up, I will add some snapshots for pointing out the problem.

Thanks in advance -
VD

PS: Sorry for broken english, it's not my first language ......

Name tags do sometimes show through walls. No getting around that. And a wall texture with an alpha-mapped window in it is a 32-bit tga texture, which gets treated differently than a 24-bit texture with no transparency when you have other alpha-mapped textures nearby. I think the viewer treats the name tags as an alpha-mapped texture in many regards...

Yep, it's the dreaded "alpha sorting" problem. Any texture with an alpha channel (including any texture that has any transparent areas at all, even if only in a small part) will sometimes allow other items behind it that *also* have alpha channels to show through, from certain angles and especially if the objects are very close to each other. And I'm pretty sure Ceera is right that name tags suffer from this - they are translucent, you can see through them, so there must be some sort of alpha channel involved.

If it's really a problem at your place (lots of avatars around, or other alpha textured objects nearby), you can try making windows with a hollowed cube instead, with an actual real hole. That way you can texture the solid part with a "solid" plaster texture, and only use an alpha texture for the part you're supposed to be able to see through anyway.

FYI - On my higher-quality builds, I use the extra prims needed to allow me to use 24-bit textures on all solid surfaces, and I only use alpha-mapped textures for the window frame and panes. This looks better anyway, as the window can actually be inset slightly into the wall. And it eliminates all alpha-sorting issues on the completely non-alpha wall sections.

This means a wall with a window in it takes 5 prims. Wall below, wall above, wall on either side, and the window and frame. Adding another window the same height to that wall adds 2 prims, for another window and another mid wall segment.