Wonky "monitor" effect for video? how?

Just curious as I’ve been watching quite a few sci-fi stuff reciently, most notably the Andromeda series.

Is it possible for blender to mimic the kind of distortion that happens when a TV monitor is affected by a magnet or interference.

You know the thing where parts of the screen are skewed to the left while other parts are skewed to the right and do it for a timed sequence.

Its most often used when a star ship/sub/control room is hit by a blast and all the monitors go on the fritz showing “wonkyness”

Back in the old Cathode Ray Tube (CRT) days, monitor images were scanned to a screen one horizontal line of “pixels” at a time. An electron gun would fire a spot onto the screen, and the location of the spot scanned across horizontally and then it would move down vertically and do another line. The old analog electronic circuitry that accomplished this had to have the horizontal and vertical scan rates synchronize with the signal frequency. The screen would go “wonky” when the vertical and/or horizontal sync circuit went out of sync, which could easily happen with electrical or magnetic disturbance. As far as I know, CRT screens aren’t being made anymore, and most of the monitor circuitry is digital and shielded, so this effect doesn’t really happen in modern equipment, but it still looks pretty cool.

You could simulate it with a setup like this where you animate a few parameters. A much better simulation could bring in snowy static (signal loss), a blanking rate, etc., but this should get you started.


And here’s the animation: http://youtu.be/91gCFLIfITE

Thank you for that, I shall have a play with it :slight_smile:

PS, sorry I didn’t say thanks sooner, my bad.

No worries. I added an optional snow effect (loss of signal), and I’ll upload the file here or to blendswap if anyone is interested. One important point to note: putting movies in the image texture node for cycles only works in recent builds (after the official 2.65 release). For reference, I made the screenshot using Windows build 54087.