Why can't hardware ports do screen melts?

http://doom.wikia.com/wiki/Screen_melt said:
Because of the nature of the effect (relying on raster graphics), it is not present in any current GL source ports.

This sounds like a pretty lame excuse to me. Has no one just ever bothered to recreate the effect?

Evidently. I'm pretty sure you can get the screen in OpenGL. Get it, make a texture from it, and then do whatever the hell you want to it. I'm sure all kinds of effects could be possible.

EDGE has done the melt effect in GL for a looooong time.

Edit: since v1.27, released in November 2001.

Some ports have an option to disable wiping on software, because it may be annoying for somebody.

Yep its not that it can't be done in GL. Its just something that most GL port authors deem to be a rather low priority given the amount of work required to implement it for little benefit.

As Quasar suggests, its a matter of rendering to texture then either doing the work yourself and uploading a new transformed texture each frame or do it using a fragment program.

Well if EDGE has it why doesn't everyone else steal the code. I like the wipe effect! Crossfades are dumb!

I've been using glboom.exe in Pr for ages. The lack of melting is not something I'm pining for.

entryway said:

Some ports have an option to disable wiping on software, because it may be annoying for somebody.

When I requested this option in Prboom+, the specific reason was that it could be very slow at high resolutions. This problem was especially bad in the original Prboom 2.02, though in fairness at the time of its release it may not have been extensively tested at 1600x1200.

Well if EDGE has it why doesn't everyone else steal the code. I like the wipe effect! Crossfades are dumb!

In Doomsday's case its because we currently do not have any system implemented for rendering to texture other than that used by the screen-shoting routine(s). We want a proper system in-place to handle this before we start trying to do per-frame effects.

We currently plan for a large scale rewrite of Doomsday's renderer for 1.9.1 as we want to make use of all kinds of fancy new(ish) effects anyway (many of these necesitate rendering to texture so we will be implementing that then).

Not to mention there has been some rather large incremental paradigm shifts within the engine recently. So, we feel it would be a good idea to take a step back and analyze what we have currently. Then, look to see if there are any large-scale changes that can be made to make life easier/improve performance and prevent inadvertanly going in the wrong direction development-wise.

Once we have the renderer updated you can expect some of the tricky-to-emulate-in-GL effects to return (such as screenwipes, proper "fuzz" invisibility etc).

I thought zdoomgl and/or gzdoom has the melt?

Mancubus II said:

I thought zdoomgl and/or gzdoom has the melt?

Nope. Hell, crossfade and burn don't even work in GZDoom. No matter what it's set to it always just instantly jumps to the intermission/whatever else.

DaniJ said:

Once we have the renderer updated you can expect some of the tricky-to-emulate-in-GL effects to return (such as screenwipes, proper "fuzz" invisibility etc).

Are you going to make the spectres have a sort of Predator-style warp? That would be neat.

Are you going to make the spectres have a sort of Predator-style warp? That would be neat.

Once all rendered surfaces are using the planned system it would certainly be possible yes. It will also mean the same shaders can be used on both spectre sprites and models.

We plan to have a fully intergrated fragment shader system, where users can create their own effects via DED definitions (this will allow for some cool effects in mods and addons).

No doubt there will be some predefined effects shipped as part of the standard package too (e.g. new liquid surface effects to (optionally) replace the water/lava/slime etc flat animations).

I'm with Ling on this one. The screen melting effect is one of those unique things that makes Doom Doom and more GL ports should implement it.

I was playing around with ZDaemon (which is software) on hi res and the melt effect looked ugly. The burn effect in particular looked quite nice, though. If you change one thing, you often need to change others to go with it. I'm not saying melt can't be made to look good in hardware rendering (haven't checked EDGE's implementation), but you can't necessarliy expect to be able to implement everything as in DOOM once you change this or that, and you can often find good alternatives.