Trails Node

Trails keeps an internal buffer of the previous frames. On each new frame, it shows the current frame PLUS the earlier frames attenuated by the Gain, optionally moved/rotated/scaled.

It works best with elements that have an alpha channel (text, logo, particle) - the transparent areas don't interfere with the buffer. On a full-frame image without alpha, the buffer accumulates everything → the result can be chaotic, unless that is the effect you are after.

• Effects Library: Tools > Effect > Trails
• Quick add: right-click in the Node Editor → Add Tool > Effect > Trails

Motion Blur

A directional blur applied within a frame. Simulates the camera shutter. No memory of previous frames.

Vector Motion Blur

A directional blur computed from motion vectors (frame to frame). More precise than Motion Blur for rendered shots.

Trails

Accumulates the previous frames, visible with a falloff. Recognizable copies of the past frames, not a continuous blur.

Rule of thumb: for "natural" motion blur → Motion Blur. For a visible multi-instance / echo effect → Trails.

• Input (orange) - the 2D image to trail. Better with an alpha channel to isolate the element that leaves a trail.
• Effect Mask (blue) - optional. Limits the trail to an area.

Animated Text+ (fly-in) → Trails (Gain 0.7) → Merge 2D → MediaOut
                                              ↑
                  Background ─────────────────┘

Speed lines:
Logo alpha → Trails (Offset X = 20 per frame, Gain 0.6) → Merge

Buffer & Rendering

Restart

A button that clears the buffer. A must after changing a parameter or when you want to restart the accumulation.

Preroll

Number of frames to pre-render before the current frame to feed the buffer. Without preroll, the first frame of the shot has no visible trail.

Reset / Preroll on Render

Automatic reset and preroll when a render or preview starts - guarantees a consistent result.

Visual Controls

Gain

Trail intensity. High (0.9+) = a long trail, each frame stays visible for a long time. Low (0.3) = a short trail that fades quickly. 0 = no trail.

Rotate

Rotation applied to each buffered frame before the merge. The trails rotate → a spiral, vortex effect.

Offset X / Y

Offset applied to the buffer on each frame. Classic speed lines: Offset X = 20 → the previous copies shift to the left.

Scale

Resizes the buffer on each frame. Scale < 1 = smaller and smaller copies (zoom-out effect), Scale > 1 = growing copies (explosion/expansion effect).

Blur Size

Blur applied to the trails before the merge. Softens the result for a more ghostly effect.

Blending

Apply Mode

16+ blend modes between frames (Normal, Screen, Multiply, Overlay, Color Dodge...). Screen is the most common for bright elements.

Operator

Compositing mode (Over, In, Held Out, Atop, XOr).

Subtractive / Additive

Controls the math of the composite.

Alpha Gain & Burn In

Fine-tunes the transparency of the trails. Burn In = the trails can glow brighter.

Merge Under

Puts the current image behind the trails instead of in front. A different visual result: the trails hide the current object.

• The Trails buffer is stateful: it depends on the previously rendered frames.
• Playing back from the start without a reset = the buffer holds the frames of the previous playback, unpredictable results.
• Always enable Reset on Render for exports. Otherwise, the first render can have a different buffer from the second.
• A Preroll of 20-30 frames = the buffer is already filled when you reach the first visible frame. Essential if the Trails effect starts at the very beginning of the shot.

• Text fly-in - Text+ animated in translation → Trails Gain 0.7 = text that arrives with a fading ghost trail. Widely used in motion graphics.
• Manga/cartoon speed lines - a high Offset X + Gain 0.6 + Blur 2 = speed lines behind a moving character.
• Onion skin for 2D animation - Trails with Gain 0.3 and Apply Mode Normal = the previous frames stay visible in the background, like the onion skin tools of 2D software.
• Retro glitch / motion echo - Trails with Scale < 1 + a slight Rotate = copies that recede while rotating, a retro psychedelic look.
• Light trails (following beams of light) - a moving bright element → Trails + Apply Mode Screen = a light streak left behind (laser beam, light on a circuit).
• Explosion / expansion - Scale > 1 + a high Gain → the element duplicates as it grows, a shockwave effect.
• Particle simulation with a trail - an animated point → Trails = a pseudo-particle with a tail. Cheap compared to a real particle system.

• Gain 0.6-0.8 is the sweet spot for visible trails without excessive saturation/stacking.
• Always feed an alpha - otherwise the buffer accumulates the whole image and creates chaos. If the input has no alpha, add a Matte Control or extract the area of interest upstream.
• Reset on Render + Preroll 30 = a reproducible render. Skipping this setting is the #1 cause of differences between preview and export.
• Apply Mode Screen for light, Normal for opaque objects with alpha. Multiply creates dark trails (shadow effect).
• Trails + Motion Blur together - Motion Blur gives a continuous blur, Trails gives discrete copies. Both combined = hyper-stylized motion.
• Performance: the buffer is resource-hungry. On a heavy shot, put Trails only on the element that trails, not on the whole comp.
• Multiple clones with the Duplicate node - for per-copy control (each copy can be processed differently), prefer the Duplicate node over Trails.