How Do I Make Slit-Scan Video Without TouchDesigner?
Load a moving video in BeamTracer Performer and add SLIT-SCAN. Choose TIME MAP → AXIS, RADIAL or NOISE to place different moments across the picture. Adjust TIME SPREAD and FRAME STEP, then add ROLL to move through those moments. Render the finished time-warp effect as MP4 or WebM in the browser.
The source keeps playing as the treatment switches from Noise to Axis and Radial. Different parts of the hands and arms come from different recorded moments. These are silent native renders of the Trina · Hands example.
Hi, I'm Trina with BeamTracer.com. Move a hand across the frame and slit-scan can stretch that gesture into its own path. A quiet background helps you see what happened: the room stays familiar while the moving parts bend through time. The map decides where each moment appears.
How do I start a slit-scan effect in the browser?
Add SLIT-SCAN to a moving source and begin with TIME MAP → AXIS. This lays the time offsets across strips of the picture. Use a repeated gesture to compare settings; a nearly motionless source will show much less change.
- Open BeamTracer Performer and open FX Rack.
- Load a video with VIDEO · IMAGE, or choose TRINA · HANDS under the source examples.
- Add SLIT-SCAN from ADD AN EFFECT → TRAILS & TIME, then select its row.
- Choose TIME MAP → AXIS and set AXIS to 0.90.
- Set TIME SPREAD to 1.30, FRAME STEP to 4 and ROLL to 0.03.
- Leave HISTORY → LIVE and AMOUNT at 1.00, then let the video play long enough to fill its recent history.
- Open RENDER, choose MP4 · H.264 or WEBM · VP9, render the clip, and choose SAVE VIDEO.
Axis 0.90, Time Spread 1.30, Frame Step 4 and Roll 0.03. Amount is 1.00; history stays live.
AXIS changes the direction of the strips. TIME SPREAD changes how the delay pattern extends across the picture. FRAME STEP changes how far apart the captured pictures are. A higher frame step gives the same set of stored pictures a longer stretch of motion to cover.
How do I make time spread outward from a point?
Choose TIME MAP → RADIAL and place the origin with CENTER X and CENTER Y. The time offsets spread outward from that point. Try putting the center near the face while the hands move through the surrounding area.
Center X 0.50, Center Y 0.45, Map Scale 2.00, Time Spread 1.60, Frame Step 4 and Roll 0.03.
MAP SCALE changes the map's reach. Move the center while watching the same gesture to see how the bends follow it. Keep ROLL low at first so you can distinguish the map's shape from its movement through history.
The HAND map offers a related treatment centered on the first tracked palm. It returns to the picture center when no hand is detected. Use Radial when you want to place that origin yourself; the clips here use fixed centers so the comparison is easier to follow.
How do I make flowing patches of time?
Choose TIME MAP → NOISE to spread the stored moments through an irregular field. MAP SCALE changes the size of that field's features, and MAP SPEED moves the pattern. This makes a different kind of deformation from the ordered strips of Axis.
Map Scale 1.50, Map Speed 0.12, Time Spread 1.30, Frame Step 4 and Roll 0.03. The slow map motion changes where the earlier gestures appear.
Choose BRIGHTNESS when you want the current picture's light and dark areas to choose the moments instead. A lit sleeve against a dark backdrop gives that map a different structure from a flat, evenly lit wall. The time-map reference covers all five choices.
Give the gesture room
Keep the moving hands and face inside the source frame. Slit-scan reads earlier pixels at the same picture position; it cannot reconstruct the part of a gesture that was outside the camera's view. A stationary camera makes the time offsets easier to inspect.
How do I hold the recorded moments or freeze them on a beat?
After the history has filled, choose HISTORY → HOLD to stop replacing its pictures. ROLL and the moving Noise map can continue changing which parts of that stored history you see. Choose LIVE to resume recording new moments.
For a musical pause, set BEAT FREEZE above zero. It briefly holds history on each detected beat for the chosen duration; zero leaves capture running. Use a track with clear beats and start with a short hold. The examples above leave Beat Freeze at zero so you can judge the maps without beat-triggered interruptions.
Check the face in motion
Strong time offsets can combine eyes or a mouth from different poses. Lower AMOUNT, use a shorter FRAME STEP, or reduce the spread when that distracts from the gesture. Check the whole rendered clip, including the first seconds while history fills.
How does this relate to TouchDesigner time displacement?
Both approaches place different moments in different parts of a picture. Xtal's Slit Scan Effect + Time Displacement tutorial explores the technique in TouchDesigner; Derivative also teaches slit-scan with the Time Machine TOP. BeamTracer gives you the ready-made maps used in this article without assembling that network.
If you want to walk around a block of recorded video in three dimensions, try Time Cube instead. For fragments that move with the picture's motion, see Mosh. Save a look once you like the slit-scan settings, then render a short MP4 or WebM to check the treatment against your own source.