Alpha not drawn correctly?

YouTube · Post by **Nash** » Mon Jul 09, 2007 4:35

http://nash.wanzafran.com/doomstuff/smoke.zip

Have a look at the included SMOKA0.png. If you examine it in SLumPed or any graphics program, it'll seem that the smoke fades out smoothly.

In GZDoom however, it doesn't fade out as smooth. It's like as if certain alpha value are ignored.

I really hope you can fix this because it poses a limitation for graphical effects.

Thanks for your time.

Post by **Graf Zahl** » Mon Jul 09, 2007 9:16

http://forum.drdteam.org/viewtopic.php?p=14176#14176

Duplicate. Unfortunately it's not that easy to fix because there's a lot of overhead involved in tracking the information through all the stages of the renderer.

YouTube · Post by **Nash** » Mon Jul 09, 2007 18:22

I see. That's too bad then. Thanks anyway.

Post by **KeksDose** » Mon Jul 09, 2007 18:28

So it can be fixed, but not that easy... hm, wouldn't be funny though to look all over for the bug in your renderer. So take your time for this. That's on your low-priority list, right?

Post by **Graf Zahl** » Mon Jul 09, 2007 21:19

Yes. This is not a bug though. To render non-translucent stuff properly I have to set an alpha threshold below which filtered pixels are no longer rendered. Unfortunately this can't be switched on selectively for certain types of pixels and to fix this I need to keep track of additional information about any texture. But to be honest, I haven't worked on the GL renderer for a long time now. Most Doom related programming I did recently was related to adding new DECORATE features to ZDoom.

Post by **KeksDose** » Mon Jul 09, 2007 21:26

Ah, so this is done to render normal non-filtered sprites correctly (so that's why my a bit alpha'd monster disappears).

This Decorate stuff sounds interesting. I saw a thread over the ZDoom forums about this (Lua), and I heard of this "Uber-Phenomenal-Legendary-Doomscript", which sounds really interesting to me.