Grainy camera effect

Hi there i'm after a visual effect that makes the camera view look grainy/ slightly pixelated, does anyone know how I can acheve this?

It doesn't need to be particually fast as its not going to be used to render every frame, its being used for just one frame every now and then.

Cheers

perhaps render to a smaller viewport - say 1/4 the screen size. Copy that to a texturebuffer and then draw a sprite using that texture which fills the screen. Should look quite blocky and be reasonably fast. You might be able to draw this with some transparency over the normal image rather than as a total replacement.

put a cube just in front of the camera with low alpha, a grainy texture and then maybe randomize the UVs?

Ahoy Grovesy,

I would put a sprite in front the camera with a simple monochrome noise texture on it, then shifting the texture a suitably long distance in random directions should make it look like authentic white noise being generated each frame.

Adjusting the size of the noise texture would give you a more blurred or sharper result..

If it's a whitenoise/interference effect you're after, try this:
http://www.blitzbasic.com/codearcs/codearcs.php?code=1183

if you want a half-life type grainy you can turn off mimapping.

Pickford: Like your idea of stretching the image to make it pixely but have not idea how to code this lol. Any change of a simple demo?

I might then combine this with the big10p piece of code which i will alter slightly. Hope thats ok big10p :) you will both get a thanks in the credits :)

Cheers guys

Code in the archives is public domain. You're free to do whatever you please, with it. :)

Hate to post just to bump my post to the top of the list (Bad me :( ) but I really could do with some code to do what John Pickford said
Quote:
"perhaps render to a smaller viewport - say 1/4 the screen size. Copy that to a texturebuffer and then draw a sprite using that texture which fills the screen. Should look quite blocky and be reasonably fast"

Cheers

This request is a scream. Pixelation has been the bane of programers who try to make true-to-life appearing graphics, and you WANT to look pixelated? LOL

Umm i don't see what's so funny about it Gak, it's obvious he's only doing it as a special effect in certain situations....

Something like this .... untested and you'll need to play with the texturescale and spritescale due to power of 2 textures etc.. and screen aspect etc...

global QGW = graphicswidth()*.25
global QGH = graphicsheight()*.25
global MainCam = createcamera()
global PixelCam = createcamera()
global PixelTex = createtexture( QGW , QGH )
global PixelSprite = createsprite( MainCam )
positionentity PixelSprite , 0, 0, 1
scalesprite PixelSprite , ?? , ?? ; 
scaletexture PixelTex, ??, ??
textureblend PixelTex , 3  ; additive blend or maybe use entityalpha 

In the main loop ....

Cameraprojmode MainCam, 0
Cameraprojmode PixelCam, 1
renderworld()
copyrect 0,0, QGW, QGH , 0, 0, backbuffer(), texturebuffer( PixelTex )
cameraprojmode PixelCam, 0
cameraprojmode MainCam, 1
renderworld()
flip

This should give you a basis, if you need a working example then give me a shout.

Stevie