Looking for a name of this visual effect

Started by
3 comments, last by mikiex 12 years, 1 month ago
Alright, I know what the effect I want, but I don't know the name of it. It's where a line slowly moves in a vertical direction, making that part of the image a bit distorted. You can see it in Borderlands' menu and Cholo game (it's an obscure robot controlling game, an image is found here, the line I'm talking about is in middle of the screen, moving downwards).

Basically what I want to create is an effect where that line moves the pixels right a bit, the pixels are moved more the closer they are to the line. I tried looking for the name of this effect, but the closest I can find is "scan lines" which isn't the same thing. Do anyone know what I'm talking about?

I want this effect for my 4X game, for the diplomacy screen, to simulate that it's a projection.

I'm also working on space combat part, and I was wondering if there's a website with different shader applications (I already know about facewound) that I can look at to get ideas for special ship effects? Thanks!
Advertisement
I don't know the name of the technique, and I don't think it really has a name. I think the name of the artifact is screen distortion, but that is a bit vague. Is there a reason you need the name? If you want to know how to implement the technique we can certainly explain it. I'll give it a try here just in case that is what you want:

Do a post processing blur technique. Instead of blurring the whole screen simply blur along a line. Find the distance to the line and then magnify the effect the closer it is. Also, the line should have a direction so you blur in that direction. To get a zigzag effect supply multiple lines in different directions. You can move the lines up and down the screen as necessary.

Does this answer your question?
That sounds like it might work, looks like I'll have to experiment. Thanks.
You could also try a simple glass type effect, the advantage there is that you can use any shape since you're using a bitmap to get the offset. You'll need a texture of the scene (so instead of rendering the scene to the screen, render it to a texture) and an offset texture. The offset texture stores how much to offset the scene texture, you can use average rgb, max, just r, just a, etc, and draw both textures as a quad over the screen. In a pixel shader get the offset texture color, then use that value to offset the texture coordinate of the scene texture. This means you have have an offset texture with just a blurred line (increasing it's texture coordinate by the current time to make it move up the screen), or even a circle, or dots, or whatever you want.
"Video hum" , also look up "ground loop"

This topic is closed to new replies.

Advertisement