Saving an image with alpha channel

[pspeed]

The transparent bucket’s only job is to render things in a particular order. They render after the opaque bucket and they render back to front.

This may be a good refresher on why:

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…