sorted alpha channels?

Is there a trick (inworld) to force the graphics engine to properly display an alpha channeled texture on top of another alpha channeled texture, instead of flipping randomly between the textures? Sheesh!

But.. Hopefully the new graphics engine will be able to handle this properly.
ps. I dont know when

No such animal. As I understand it, this is an issue with OpenGL, not something inside SL itself. Every game does it.

There are practical uses for the phenomenon like making fire, trees, etc., things which lots of games take advantage of. The downsides to it are just a lot more noticeable in SL than in other games because you are doing it yourself so you get to see it happen first hand.

I have noticed little glitches with it though in certain games. In World of Warcraft, for example if you get too close to a bush, you can readily see that it simply made of a few crisscrossed planes with alphas.

The order the polygons are sent to OpenGL is determined by the app/game. its possible just not easy to do. It requires cpu power to sort polygons. Theres also issues with that have large numbers or vertexes and such, but sl only uses triangles. But in cases where they intersect is an issue.. I recall in last patch they mentioned about alpha sorting, maybe they already do and were seeing intersecting ones it cant do. Id have to test that, lol. In that case you can design your things around the problem(uses more prims).

i hate looking through one object only to have any other object behind it standing out only because it too happens to have a level of transparency. I know this is a problem with OpenGL but it's real annoying. Why can't the engine simply subract one alpha value from the other and come up with a new value for what can be seen beyong those two objects?

~Lefty

This isnt a fix for all situations of course, but I found a work around for one thing i did.

I had a window in my house with alpha, and put a set of curtains on the inside of the house in front of the window (the curtain of course had alpha as well).

The damn gridlines from the window were always popping thru the curtains and it was annoying as hell. I thought of losing the window all together but it had a nice texture on the outside that I didnt want to get rid of.

I simply made the inside of the window completely transparent and left the outside as the texture it was. Granted this made the grid for the window on the inside transparent, but I was able to somewhat incorporate that grid into the curtain texture to fake it.

I think until the openGL engine is updated in SL we'll just have to keep coming up with these little tricks.

-Syn

Synergy, you can composite the window shades and glazing into one texture and then no alpha layering problems. I even made a one prim wall with a window in it to test the possibility: two textures were needed: the exterior texture with a partial alpha (0.2) on the window and an interior texture with the same layout. It worked perfectly. You can also add primwork sills and such to "frame" the window.

Good luck.

needs fixing.

This is a real problem. I guess there is no point in bugging it since someone said that it was mentioned in past release notes. I am working on console games and one has 6 layers of alpha textures. It works for the most part as long as you keep your camera perpendicular to the textures. But it sure would be nice to have this fixed.

Al, is it possible to do pac-man? Ive built a nice looking pac-man cabinet, but the game isn t playable. Id love to have you make it playable!

Im going to check out the horse racing game asap!

At first glance, i would say yes. Right now I am working with linked child subjobject motion. Something like that would require unlinked temp objects (for the dots). I have thought through collision sensing (walls). Controls are easy enough. Yeah, I think so. Now, having said that, I don't think it is top of my list right now. But somewhere down the road...

I've had 32 prims with alpha textures stacked on top of each other with no sorting problems. The trick is to leave enough space between them (cant remember the gap size of the top of my head, but I think its something like 0.025). Also, all my alpha planes are at exactly the same rotation, and the whole linked object is aligned exactly vertical.
If I rotate the object around two different axis (say, X and Z) then sorting problems occur, but on the whole it works pretty well.
Check out the 3d map on the NE (i think) corner of seacliff as an example.

I've hoped and wished for a better alpha sort for ages and ages. I live in hope that one day we'll get it

In my experience, there are no sorting problems between parallel or perpendicular prim faces. The sorting problems between two prims will appear when those prim faces are not either parallel or perpendicular. This means cylinders and spheres are especially prone to sorting problems.