pixeldestrukt

work ongoing

vlfo

Video LFO. ISF shaders driven from Pure Data over OSC, live in a window, rendered offline at any size, or published over NDI.

Status
ongoing
Year
2026
Stack
Rust, wgpu, ISF, GLSL, OSC, Pure Data, NDI
Repo
github.com/pixeldestrukt/vlfo

What it does

Loads an ISF shader and makes every one of its inputs a knob. Each input is reachable over OSC as /vlfo/<NAME>, so a Pure Data patch can drive it with LFOs the way it would drive a synth. The same shader runs live in a window, renders offline to PNG frames at any size, or streams out over NDI.

vlfo run shaders/vlfo-test.fs             # live window, OSC on udp 9000
vlfo render shaders/vlfo-test.fs -o out --frames 300 --fps 30 --size 4800x7200
vlfo serve shaders/vlfo-test.fs --ndi vlfo-1 --output 1920x1080 --fps 60

It is the successor to glfo, my old Pd/GEM performance framework. The Pd side of a scene stays in Pd; only the drawing becomes a shader.

How it works

  • Shaders as patches. vlfo inputs --pd shader.fs writes a Pd control panel with a number box, toggle or bang per input, already wired up. Shaders reload on save and keep their current input values. A shader that fails to compile is reported and the previous one keeps running.
  • Node graphs. A .vlfo file describes a shader as chains of nodes, one per line, GEM-style: transforms (translate, rotate, grid, mirror), a shape (rect, circle, ring), then paint (hsv, alpha, outline). Every numeric literal becomes an OSC input automatically. Coordinates are GEM world units, so numbers from old glfo scenes carry over.
  • Deterministic rendering. Logical time is frame / fps, so a 4800×7200 render is just slower, never sped up.
  • NDI without linking. The NDI runtime is loaded at run time. Render resolution is independent of the preview window, and if the sender falls behind, frames are dropped with a warning rather than stalling the renderer.

Status

First slice: one ISF shader per process, headless rendering, NDI out, and vlfo check for testing which files from the public Vidvox ISF corpus translate through naga. Multi-pass PASSES, persistent buffers, image inputs, layers and audio are not in yet.