I make VJ loops, and there's one thing about them that has always bugged me: a loop is finished the moment you export it. If you want it a bit faster, a bit thinner or in another color, you have to go back, change it, render it again, export it and put it back in your deck. Do that across a whole set and it gets old quickly.
ISF shaders work differently, and I think they're underrated in the VJ world. Instead of a video file, you get a small piece of code that draws the image live while you play. In this post I'll explain why that matters, using two shaders I made as examples: Minimal Tunnel and Concentric. Both are inspired by VJ loops I already sell, so you can see the same idea in both formats.
The limit of a clip
A video clip is frozen at export: its length, resolution, colors and motion are all decided. You can tint it, slow it down or put effects on top, but you're still working around something that's already done.
For a specific symbol, texture or mood, that's exactly what you want. For a visual that should react to the track or to what's happening in the room, it gets in the way. And more variations means more files to store, load and keep organized.
What an ISF shader is
A shader is a small program that runs on your graphics card and draws every frame from math, in real time. ISF (Interactive Shader Format) is the open format that lets VJ software read them. You drag the .fs file into your software and the controls show up as sliders, which you can map to MIDI, OSC or audio.
Nothing is stored as video, so nothing is fixed. You move a slider and the picture changes right then, at whatever resolution you're outputting. It works in Resolume Wire, VDMX, MadMapper, Magic Music Visuals, Synesthesia, Millumin, Smode, TouchDesigner and Max/MSP Jitter. If you're still choosing software, our VJ software guide is a good place to start.
Any resolution, any aspect ratio
A shader draws the image at whatever resolution you set in your software, so the same file works on any output: 16:9, HD, 4K, triplewide or a custom canvas.
I've tested both shaders in MadMapper at triplewide and at other resolutions, and changing the canvas size is just a setting. The same logic applies in the rest of the software that supports ISF: the shader follows whatever canvas you define. That's useful if you work with different screens from one venue to the next, or with projection mapping where the canvas is far from a standard 16:9.
Clip vs shader, side by side
| Video clip | ISF shader | |
|---|---|---|
| Variations | One per file | As many as the sliders allow |
| Live control | Playback and effects | Every parameter |
| Loop point | Yes, and it has to be seamless | None, it runs continuously |
| Resolution | Set at export, one version per format | Whatever your output is, from 16:9 to triplewide |
| File size | Megabytes to gigabytes | A text file |
Minimal Tunnel
Minimal Tunnel is a 3D tunnel you fly through. It's built from rings of boxes, octahedra or tetrahedra, each with its own random size and rotation. There are no 3D models and no video behind it: the shapes are calculated mathematically for every pixel on every frame (raymarching, if you want the technical word).
It's inspired by my tunnel loops: Abstract Tunnel / Fractal Tunnel (16 loops in 1080p) and Minimal Tunnels / 5K (10 triplewide loops). A loop gives you one fixed fly-through. The shader gives you the same idea, but you can change it while it plays.
That's why one file covers so many looks. With the controls you can:
- Switch the shape, which changes the character of the whole tunnel
- Change the depth, fog and vanishing point, from dense and tight to open and deep
- Add angular jitter and random scale so it looks less regular
- Adjust the camera sway and speed to follow the energy of the set
- Lower the quality/steps if your computer struggles, or raise it if it doesn't
It's €11.99 and you can get it here: Minimal Tunnel.
Concentric
Concentric is the opposite: flat, graphic and simple. It draws concentric shapes, either circles or polygons from 3 to 200 sides, with up to 20 layers. Each layer can be rotated a little from the previous one, and that's what creates the spirals.
It's inspired by my Futuristic Lines / 5K pack, which mixes minimal techno lines, concentric circles and fast linear motion in 8 triplewide loops. Same look, but now you control it.
A segment control lets you draw only part of each ring and animate it, similar to a trim path in After Effects. Line width goes from 0.5 to 500 px, so you can get anything from hairlines to very thick strokes, and you can set the color and the spacing between layers.
One easy thing to try: map the segment size to the kick drum and the rings follow the beat. It takes a single MIDI assignment.
It's also €11.99: Concentric.
What shaders can't do
Shaders don't replace clips. They won't give you real footage, a specific character or a shot with natural texture, and for that you still need clips.
Where they work well is abstract and geometric visuals, and that's a big part of what runs behind a DJ. Using both together works nicely too: a shader on one layer, a clip on another, blended, and the result changes every time you touch a slider.
If you want to try them
Both shaders are a one-time purchase. You get the .fs file with the full source code, commercial use is allowed, and updates for each shader are free. No subscription.
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