Feedback Start
Start point of a feedback loop, where each iteration's output becomes the next iteration's input.
What it does
Feedback Start opens a feedback loop: a piece of graph that runs several times, feeding each pass's result back in as the next pass's input. Pair it with Feedback End, which closes the loop and sends its output back here.
Mode sets how the loop behaves. Continuous runs a fixed number of iterations every frame and carries state forward frame to frame, for physics or particles that evolve over time. One-Shot runs its iterations once and returns the final result, for procedural builds such as fractal or L-system generation. While keeps iterating while a wired-in condition stays true, up to a safety cap.
When to use it
A value (a position, a shape, a count) evolving step by step, each step building on the last.
A simulation that keeps running and accumulating state across frames: Continuous.
A fixed procedural build run once for its final result: One-Shot.
A loop that runs until a computed condition stops being true: While.
| Parameter | Type | Default | What it does |
|---|---|---|---|
mode | String | "Continuous" | Continuous = run N times per frame, One-Shot = run N times and stop, While = run until the condition is falsy (capped by iterations). One of: Continuous, One-Shot, While. |
iterations | Number | 1 | Number of feedback iterations (the max-iteration safety cap in While mode) |
condition | Number | 0 | While mode: loop continues while this is truthy (non-zero) |
substep_delta_time | Boolean | true | Divide delta time by iterations (for physics substeps) |
reset | Boolean | false | Reset state to initial values |
strength | Number | 1 | Effect strength / wet-dry (0 = no effect, 1 = full). Editable, wirable, keyframable. |
Gotchas
While mode checks the condition before each iteration, so a condition that starts falsy never runs the loop. Iterations remains a hard safety cap in While mode, so a condition that never goes false will not run forever.
Reset appears only in Continuous mode, the only mode with state that persists across frames. Trigger it to snap the loop's state back to its initial values.
In Continuous mode, turn on Divide delta time by iterations for physics substeps. It splits the frame's time delta evenly across iterations, so the simulation stays stable at higher iteration counts.
Worked example
Add a Feedback Start and a matching Feedback End, then wire End's feedback output back to Start's initial-value input to close the loop.
Set Mode to One-Shot and Iterations to the number of passes you want, then build the per-iteration logic between Start and End.
Switch Mode to Continuous for a running simulation, and wire a trigger into Reset to snap the state back to its starting values.
See also
Feedback End · For Start · For End · Iterator