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Parameters & Live Performance

Once a shader is loaded, Shader Engine behaves like a first-class Resolume effect. This page covers its parameters, audio reactivity, and what makes it safe to lean on during a show.

The parameter groups

Select a layer/clip with Shader Engine and you’ll see these parameter groups:

Load

  • Shader Path — the file picker; also stores which shader this instance uses (so it’s restored with your composition).
  • Browse Library — opens the Shader Engine window (library, ISF/Shadertoy, editor).
  • Status — shows load/compile errors. Empty = healthy.

Controls

  • Rate — time/playback speed. 0 pauses the shader; positive runs forward, negative runs in reverse. Use it to freeze, slow-mo, or scrub time-based shaders.
  • Control 1 … N — the loaded shader’s own inputs. These are hidden until a shader loads, then appear named after the shader’s ISF inputs.

Audio

  • Audio FFT — a 256-bin audio spectrum fed to the shader. Shaders that declare an audio input become audio-reactive automatically (see below).

Milkdrop (Source variant only)

  • Blend Time and Beat Sensitivity — for Milkdrop .milk presets when using the Source plugin.

Shader inputs become Resolume controls

Every input an ISF shader declares — sliders, colors, toggles, points — is mapped to a Resolume Control parameter with the shader’s own range and default. That means you can:

  • Automate them on the timeline,
  • Map them to MIDI knobs/faders,
  • Map them to OSC, and
  • Dashboard them like any other Resolume parameter.

There’s nothing special to learn: if you can map a Resolume effect parameter, you can map a shader input.

Audio reactivity

Feed the Audio FFT parameter from Resolume’s audio (or map it as you would any FFT-driven effect), and shaders written to respond to audio will pulse, morph, and move with the sound. The FFT is 256 bins, so shaders get a detailed spectrum, not just a single level.

Built for the stage

Shader Engine is designed to be trusted in a live set:

  • Broken shaders fail safely. A shader that won’t compile or errors at runtime never takes down your composition — you see the error in Status and everything else keeps running.
  • Many instances at once. Shader Engine has been tested with 160+ simultaneous instances in a single composition. Put as many as your GPU can handle; each is independent.
  • Async loading. Shaders parse off the render thread, so loading a whole clip column fills in gradually instead of stalling playback.
  • Offline-first. Local playback never depends on the network. Only web discovery (Shadertoy/ISF search) needs a connection — your loaded shaders keep performing regardless.

Performance tips

  • Resolution drives cost. Shaders render at the composition/clip resolution; heavy shaders are far cheaper at 1080p than 4K. Drop resolution before dropping shaders.
  • Watch your GPU, not your CPU. Shader work is on the GPU. If you’re stacking many instances, GPU headroom is the limit.
  • Pause with Rate. Setting Rate to 0 holds a shader on a frame with essentially no animation cost — handy for freezes and for parking expensive shaders you’re not actively using.
  • Stage per gig. Keep a per-set library folder (see The Library Browser) so everything you need is one click away mid-performance.

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