some semi-visible objects?

I've run into something a bit strange...

I was building some walls with windows in the texture (alpha channels) inside the building were some pipes with alpha channeled texture too (rust holes), the thing is....when you look at the building from certain angles, sometimes the pipes seem to be on the outside...and the walls would disapear or some parts of it would become invisible.

The other walls (without alpha channels) work perfectly but it seems that most of the objects textured with some transparent parts have this problem. They just behave in a weird way....appearing to be in front or behind objects randomly, depending on where you look at them from.

Is there a way to fix this?

Try setting each of those objects to at least 1% transparency in the texture tab.

I've seen the same effect when building a river. I set the water texture to something like 20% transparency, and it seems that square prims always render in front of things like toruses, from most angles and distances, regardless of their positioning. Really annoying stuff.

I tried fiddling with transparency and every other setting......in vain. I tried everything and still....i get very weird visual effects.

Oh well....maybe someone will come up with solution

I seem to recall something about this being an opengl problem, but i could be wrong.

It's a bug in their alpha sort procedures, it would seem. Been there since day one. Can't imagine it's inherent in OpenGL or every other OpenGL program would have the same problem.

As far as I can tell, the developers at Linden Lab have gotten so used to it (as has almost everyone that plays) that they don't take it as a high priority.

For me, it's in my personal top 3.

Just look how your avatar's shadow renders OVER your feet and any prims you wear there. I have white feet and ankles so it's very obvious.

And it's ALWAYS been like that.

Yes. It sounds like a problem with their Z ordering algorithm. It looks like screen-door transparency could help if we had access to it. More information can be found here:

http://www.opengl.org/resources/faq/technical/transparency.htm

~Ulrika~

I've been having this problem a lot too... but just recently... and even with objects that I never had problems with pre 1.5. I seem to recall reading something in the past about other z-ordering based problems but I had never had any myself until now. I've pretty much thrown out a lot of textures that were at least partially alpha because of this "feature".

UPDATE: speak of the devil... I just got a response back on the bug report I filed for this a week or so ago... here's the gist of it: (From Kelly Linden)

"...This is a known issue with transparent textures on objects that have very close centers (or in this case the same center). IF you are not using any transparency in a texture you are uploading be sure to save it as a 24 bit TGA not a 32 bit TGA. The extra bits are the transparency and if you include them then SL thinks it has transparency and it will show this bug..."

In other words, some textures that we have that appear to be solid will cause the bug because they were saved in the wrong way. I hope all the texture creators out there are reading this.