Loop

Cycles upstream content over a fixed-length window.

Category: Time Menu path: Time > Loop

Ports

Port	Type	Direction	Description
in	imageRgba16f	input	Upstream animated content.
out	imageRgba16f	output	Looped version of the upstream content.

Parameters

Param	Type	Default	Description
mode	enum	Cycle	One of Cycle / PingPong / HoldLast. See "How It Works".
length	scalar	30	Loop window length in comp frames. Minimum 1.

Expose Channels

Port	Type	Overrides
length_in	scalar	length

How It Works

The output frame is computed by mapping comp_frame into a [0, length) window:

• Cycle (default): modified_frame = comp_frame mod length. The window repeats forward forever — frames 0..length play, then frames 0..length again, then 0..length again, ...
• PingPong: same window, but every other cycle plays in reverse — 0→length−1, then length−1→0, then 0→length−1, ... Useful for back-and-forth swing motions.
• HoldLast: the first length frames play normally; everything past that holds on length−1 (the last frame in the window). Like a clip that stops at the end without disappearing.

Re-evaluates upstream at the computed modified_frame using the same primitive as TimeShift and FreezeFrame.

Usage Examples

Looping animation

30-frame walk cycle → Loop(mode=Cycle, length=30) → Output. Plays the walk cycle forever.

Pendulum / breathing motion

Animated swing 0..60 → Loop(mode=PingPong, length=60) → Output. Smoothly reverses each cycle for a continuous back-and-forth.

Hold the last frame

30-frame intro animation → Loop(mode=HoldLast, length=30). Plays the intro once, then freezes on the final frame.

Animated loop length

Time → Math → Loop.length_in. Ramp the loop length to gradually slow down a cycle, or speed it up.

Tips

• Loop is comp-frame anchored at 0 — the loop window starts at frame 0 of the comp, not the layer's clip start. Use TimeShift upstream of Loop to align differently.
• For PingPong, an even-cycle starts at 0; odd-cycle plays in reverse. The seam where forward meets reverse is the same content frame (no jump).
• For animated content with simulations, ensure the simulation is stable across the looped range. Stateful sims like PointAdvect cache by frame index, so cycling re-uses cached past frames cheaply.

Related Nodes

• Time Shift — re-anchor the loop with an offset.
• Freeze Frame — HoldLast is conceptually a Loop whose window matches a single point.
• Posterize Time — combine with Loop for choppy looped motion.
• Echo — sample at multiple offsets and blend rather than cycle.
• FileCache — bake upstream for fast loop reads.