Batch Repeater Controls: Item Count, Length Policy & Per-Item Inputs

A Batch frame's properties panel sets how many times the interior runs (item count), how short lists behave (clamp vs cycle), and which interior input each per-item value list feeds.

Where: Batch frame → properties panel — Tune the repeater: count, length policy, and per-item inputs

Key ideas

• Item count: N is auto-derived from the longest per-item source, or you can type an explicit Count to override it (clear the field to return to auto). The frame header shows ×N and the Run button reads 'Run batch ×N'.
• Length policy: When per-item lists differ in length, clamp stops at the shorter list's end (no value past it) while cycle wraps and repeats values to fill N.
• Per-item inputs (bindings): Each input card binds a source to a target node + handle: a List of typed values, or Nodes (gathered) where each selected node contributes one item. The handle list adapts to the target node type (Prompt, Start frame, End frame, Reference image, Image, Video, Audio).

Steps

1. Open a Batch frame's properties (it has nested nodes inside it).
2. Under Items, leave Count blank for auto (longest source) or type a number to force N.
3. Pick a Length policy — clamp to stop at the shortest list, or cycle to wrap values to fill every item.
4. Under Per-item inputs, click Add input, choose the target interior node and its handle, then switch the source to List (type values, one per item) or Nodes (check the source nodes to gather).
5. Click Run batch ×N — the panel shows progress (current/total) and a per-target results row when it finishes; the estimated spark cost is shown beneath the button.

FAQ

What's the difference between a per-item input and just wiring a node into the batch?

A plain wire into an interior node is a broadcast input — read live the same way on every iteration. A per-item binding turns one input into a list so each iteration gets a different value; only per-item sources determine the item count N.

My batch ran fewer items than my list had — why?

With clamp length policy, a binding stops at the end of its shorter list, so N is governed by the source lengths and policy. Switch to cycle to wrap shorter lists, or set an explicit Count to force the number of iterations.