Video Motion Trail 🌌

Motion trails are the visual signature of long exposures and light painting: a moving subject smears a fading ghost of itself across the frame. The Video Motion Trail node from TensorVizion/OmniNodes gives your generated clips that look - by blending each frame with a decaying accumulation of the frames before it. It's a creative effect node, pure tensor math with zero dependencies, and it's the temporal counterpart to the single-image looks the pack's Image category already provides.

The mechanism is straightforward: walk through the batch in order, keeping a running "trail" buffer that accumulates previous frames at a decay factor. Each output frame is a blend of the current input frame and the accumulated trail, mixed by blend_strength. Two accumulation modes change the character of the effect:

• average (default) - soft, dreamy accumulation. Trails wash together gently; good for a smooth, painterly motion blur.
• lighten - keeps only the brightest value per pixel across the trail. This is the classic star-trail / long-exposure look: moving highlights draw crisp bright streaks while dark regions stay clean.

Inputs and outputs

Three inputs: decay (0–0.99, default 0.85 - how long trails live; 0 means no trail at all, each frame is just itself, and values near 0.99 give very long-lived ghosts), blend_strength (0–1, default 0.6 - how hard the trail is mixed into the current frame), and trail_mode (the two modes above). One output: images.

There's no summary output on this one - it's a pure effect node, in and out.

Install

Ships with OmniNodes:

cd ComfyUI/custom_nodes
git clone https://github.com/TensorVizion/OmniNodes

Or ComfyUI Manager → OmniNodes → restart. No dependencies - it's pure PyTorch tensor math. Under TensorVizion/Video.

Troubleshooting

• Effect is invisible - decay at 0 disables the trail entirely, and a low blend_strength barely mixes it in. Crank both up to see it; then dial back for taste.
• Everything is a white smear - lighten mode on bright footage accumulates toward white. Drop decay or blend_strength, or switch to average.
• Trail drags in the wrong direction - trails always follow the previous frames (backward in time), which is the correct long-exposure behavior. If you want the effect behind moving objects the other way, you'd need a different node entirely.
• Node missing - restart ComfyUI and check the [OmniNodes] terminal log.

Reach for it when a clip needs a dreamy or long-exposure feel. It's one of the few purely creative nodes in an otherwise utility-heavy pack, and it's fun to throw at a slow camera-pan clip and watch it ghost.