ISF

Runs a user-loaded ISF (Interactive Shader Format) shader. Load .fs... opens a file dialog filtered to .fs files; the shader’s own declared inputs determine what parameters appear, not a fixed list this module owns.

Parameter	Control	Notes
Shader	file picker (Load .fs...)
Blend	Selector	Add, Multiply, Screen, Difference, XOR, Replace, or Phoenix into the chain.
Mix	Trough	Wet/dry of the shader’s result.
Shader Inputs	varies	Generated from the loaded shader’s own metadata; shape and count vary shader to shader.

An ISF shader is a separate mechanism from the fixed 43-type Insert FX catalog: an ISF module also carries its own Insert FX chain, stacked after the shader’s own result, not as a 44th catalog entry. See Insert FX Chains.

Filters and generators

A shader whose header declares an input with "TYPE": "image" (usually named inputImage; transitions declare two) is a filter and reads the chain. A shader with no image input is a generator.

A filter receives the chain over black, as most ISF shaders expect. Its result, after the module’s own Insert FX, keeps the chain’s see-through areas: wherever the chain above has anything, the result is kept as drawn; where the chain is empty, only the parts the shader lights are kept and dark parts stay empty. A generator’s result is used as drawn, with its own alpha. See Signal Chain.

NOTE: a filter set to Blend XOR or Phoenix treats a dark result over an empty area as empty.

Related: AUX Sends and Buses.