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Geometry effect

Blob Tracker

Blob Tracker is a kaleidoscope and geometry effect in FRCTL, the browser VJ studio. Finds the masses in the frame and stakes them out with brackets, glyphs and scattered grid lines.

Runs live on video, images, a camera or generated art. Stack it with any other effect, and route LFOs, envelopes or any of ten audio bands to its controls so it moves with the music.

Try Blob Tracker free All effects

The untouched demo art: an eye inside a triangle over wavy teal, blue and peach lines — Source

The eye-in-triangle art dimmed, with teal corner brackets, crosshairs and small glyphs placed around the triangle — Blob Tracker, default settings

What Blob Tracker does

Scans the picture for masses brighter than their surroundings and marks the ones it holds with corner brackets, which fade up over a third of a second and linger after the subject leaves. Readout glyphs and grid lines re-deal several times a second, crowding round what it has found, and the frame greys back behind them. Sense sets the lock threshold, Scale the box size, and Hue the overlay colour.

Using Blob Tracker

Where it works: Surveillance and sci-fi HUD looks on performer footage, crowd shots and live camera. The boxes follow whatever is lit, so a camera on the DJ or the dancers gives it far more to do than a still.
With the music: Glyphs and lattice lines re-deal on their own timer, with Speed setting the pace. B8 on Grid makes the hats flicker more lattice in, and B1 on Glow flashes the whole overlay on the kick.
Starting point: Sense at a quarter so it locks easily, Scale and Icons at centre, Grid at centre, Glow at three-quarters, Hue at centre for teal.

Controls

Sense: How strong a mass has to be before the tracker locks onto it.
Scale: Size of the masses it looks for, and the size of the boxes it draws.
Icons: How many readout glyphs spawn around a lock.
Grid: How much of the scan lattice is drawn each tick.
Glow: Overlay brightness against the frame.
Hue: Overlay color.
Speed: Rate of the effect motion. Centre is the authored speed, hard left a tenth of it.

Pairs well with Blob Tracker