Feedback smear effect for image trails
Feedback Smear builds a trail from offset samples of the current image. Buildup makes the trail stronger immediately, including while playback is paused.
Compare the immediate trail while paused with Frame Echo, which uses earlier rendered output. Choose this effect when a still image needs directional repetition.
Creative applications
- Stretch cover-art lettering into a directional trail.
- Add a swept texture to a digital collage or portrait.
Starting workflow
- Choose an image in the Feedback Smear demo and leave playback paused to compare settings.
- Set Horizontal drift or Vertical drift to choose the trail direction.
- Increase Buildup, then adjust Amount to balance the clear source against the repeated trail.
- Inspect the edges and export a still when the main subject remains readable.
Key controls
- Buildup
Increase the accumulated trail immediately; playback is not required.
Default: 50% · Range: 0% to 100%
- Amount
Control the retention of successive offset samples within the smear.
Default: 0.89 · Range: 0 to 0.99
- Horizontal drift
Steer the repeated samples horizontally; reverse the sign to reverse direction.
Default: 0.005 · Range: -0.05 to 0.05
- Vertical drift
Steer the repeated samples vertically or combine with horizontal drift.
Default: 0 · Range: -0.05 to 0.05
Practical tips
- Keep one drift direction small when you want a clean directional smear.
- Compare Buildup and Amount separately to understand how each changes the trail.
- Judge a bright edge and the image boundary separately: repeated samples can make the edge of the frame look stretched.
Limitations
- This is a spatial approximation of feedback, not a recording of earlier rendered frames. It does not require history warmup.
- Zero Buildup, zero Amount, or zero drift on both axes returns the untreated source.
