original Doom special effects in OpenGL

woahholynose · Post by **woahholynose** » Sun Oct 22, 2006 23:14

Would it be possible to do DOOM's original screen melting effect for level transitions in OpenGL?

Also, would it be possible to do the original Spectre invisibility effect in OpenGL?

These are the only two things missing in GZDoom, really.

Thanks guys.

Post by **Enjay** » Sun Oct 22, 2006 23:47

Both have been discussed before and both are problematic in hardware renderers apparently.

Personally, the screen wipe - I couldn't care less about.

The spectre effect. The original always looked like a computer effect to me. Like it wasn't there. When Heretic came out with proper translucency, to me it looked so much better and more believable (yeah, I know). The GZdoom implementation (which I believe has its roots in PRBoom?) looks great to me.

However, I can understand people wanting both of these effects for old times sake, or whatever.

Post by **wildweasel** » Mon Oct 23, 2006 1:37

I personally despise the screenwipes, especially during testing sessions for my mods. I usually find myself repeatedly quitting and restarting GZDoom to fix minor things with my mods, so screenwipes would slow things down a lot.

The spectre effect, though - if that could be replicated in OpenGL, that would be pretty awesome, but as it stands now I'm quite happy without it...

Post by **Graf Zahl** » Mon Oct 23, 2006 9:03

Screen wipes: Sorry, I can't find the motivation to make a GL version of that code.
Spectres: Maybe with shaders it can be done but I don't want to rely on that and I think the current effect is the best approximation hardware rendering has to offer. And yes, thanks to PrBoom for finding the particular settings. All other GL ports I know of never got beyond a lame translucency effect.

YouTube · Post by **Nash** » Mon Oct 23, 2006 14:41

A neat shader effect for the Spectres would be something similar to the Predators's cloaking effect, where the background distorts behind the Spectre. That'd be awesome.

Post by **Enjay** » Mon Oct 23, 2006 19:42

I stongly suspect that's the feeling id was trying to evoke with the spectre effect. However, as I said, for me it didn't really work and just looked like a 2D laid-on effect.

Post by **Graf Zahl** » Mon Oct 23, 2006 21:51

I think they only wanted to get something translucent but the target hardware was just too weak back then.