Advanced Member Mighty Pea Posted January 20, 2015 Advanced Member Report Share Posted January 20, 2015 (edited) Depth sorting is a bit of an issue currently, as it is with Alpha Blend in all 3d applications. Alpha Test (1-bit alpha, basically. On or off) gets rid of the depth sorting issues, but looks quite bad and doesn't allow for variable transparency at all. It's useful in some situations, though. A third option is Alpha-to-Coverage, which is used a lot for hair: Alpha-to-coverage is similar to alpha test in that it requires no depth sorting, so you can avoid sorting artifacts. The technique uses multisample anti-aliasing (MSAA) to give a softer edge. This allows for about 9 levels of transparency, though these are dithered together to give more apparent levels of transparency. It renders in a single pass, but it requires at least 4x MSAA which is only available on newer hardware (NVIDIA GeForce 7 and later). Humus has a demo on his site, with sample code. Marmoset Toolbag also has alpha-to-coverage support. Giving us the option between multiple types of transparency would let us decided what works best for each situation, and make working with certain types of transparency (worst-type situations like hair, with multiple overlapping planes) much more pleasant. For more reading: http://wiki.polycount.com/wiki/Transparency_map http://blog.wolfire.com/2009/02/rendering-plants-with-smooth-edges/ Edited January 20, 2015 by Mighty Pea Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.