WinQuake (Non-GL) underwater effect in OpenGL?
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Everyone remembers that cool underwater effect of original (non-GL) Quake. The one where the screen pixels were "waved" instead of wall/floor polys. How is this screen effect implemented to OpenGL? Tutorials, anyone?
I've seen something similar in latest hi-end games, like Doom 3 (heat effect) and FEAR (shockwaves, Matrix bullet FX). What is the name of this trick?
Newer games: Refraction
Older games: sin() functions... :)
I'm using a cheap sin hack for my game, I simple grab the frambuffer, slap it onto a grid and manipulates the vertexes using sin functions...
Older games: sin() functions... :)
I'm using a cheap sin hack for my game, I simple grab the frambuffer, slap it onto a grid and manipulates the vertexes using sin functions...
I think the original quake just modified the texture coordinates using a sin function over time or something similar.
Doom 3 does a similar thing, but as a fullscreen post-processing effect. I'm guessing they render the texture to the screen and then render a screen-aligned mesh of quads with that texture and warp the vertices. Either that, or they render a single screen-aligned quad and do the warping in a fragment shader.
Doom 3 does a similar thing, but as a fullscreen post-processing effect. I'm guessing they render the texture to the screen and then render a screen-aligned mesh of quads with that texture and warp the vertices. Either that, or they render a single screen-aligned quad and do the warping in a fragment shader.
The Quake software renderer distorted the framebuffer using some trig functions. It's actually the exact same thing as doing a "post process" effect using a pixel shader, as it's done in screen-space after rendering everything in the scene.
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Quote:I'm using a cheap sin hack for my game, I simple grab the frambuffer, slap it onto a grid and manipulates the vertexes using sin functions...
Interesting approach - how did you implement that? I tried to do something similar in the past, using glCopyTexImage2D, but as there are severe restrictions of are size on that one, it didn't work out so well...
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