Alpha blending and clipping

[pspeed]

Being familiar with alpha and sorting might help here. If you haven’t already read it then this might be a good primer:

Alpha/Transparency Sorting, Your Z-buffer, and You

Since this comes up every three or four days, I decided to put together some visual aids. There is often a lot of confusion with how pixels get processed in relation to the z-buffer and why sorting is important. Most importantly it can be mind-warping trying to wrap one’s head around how to ‘fix’ the cases where proper sorting isn’t possible. Hopefully these diagrams help show the futility of it all… I mean the trade offs one has to make to get transparency looking its best in the general cas…

Especially since putting it in the sky bucket fixes the problem… there is no depth there.

It could be turning off depth write fixes it. I don’t know how the effect is done, though.