Alpha Glitch

For my performance with Freecode as part of Network Music Festival I wanted to move away from producing visuals that consisted mostly of video playback and move towards generative art. Demos of this were posted on my Flickr site, and the first performance that utilised this new approach happened on 26th January

The feedback from people online and at the performance was really positive, with a lot of people were asking how to do something similar. The patch I made for it was very messy so I (albeit slowly) remade part of the patch that achieves that effect. It’s available for download below

Alpha Glitch

Click to Download

This isn’t strictly a generative patch as it still relies on an source image/video as a texture, but I think it’s more generative than it is video playback. The patch, made in Pure Data, works first by using [repeat] to generate many cubes which are zooming towards the screen. These, then, are textured with an image of your choice. The “magic” comes in the use of [pix_alpha]. The red, green and blue sliders remove a percentage of that colour from the image texturing the cubes, revealing the cube below. The green toggle button randomly removes a different percentage of each colour at different speeds. This, coupled with the constant movement of the cubes I think creates a sort of animated glitch using only a still image.

Sound confusing? Hopefully it’ll become clearer once you dissect the patch and view the help patches of each object. Here’s an example of the output from this patch using this image from my Skin Cells video:

If you know Pure Data well you can modify the patch so that it uses videos or a webcam feed instead of a still image. However, be aware that having that many objects on screen with a video stream can cause the output to be stuttery. This patch was made with Pure Data Extended 0.43 on Ubuntu 11.10.