Radar
A plan-position radar scope, for Resolume
What it does
Two FFGL plugins for Resolume Arena and Avenue in one download: SW Radar, a source that's a radar watching a synthetic sea (a coastline, rain cells and moving contacts), and SW Radar Over, an effect that makes your clip the sea, so its bright bits become echoes painted by the sweep.
What a radar scope shows is the sea convolved with the radar. The antenna turns at its RPM, and every frame paints exactly the bearings it swept past into a fixed polar grid of 2048 bearings by 1024 ranges. A point target paints an arc as wide as the beam and a radial streak c tau / 2 long (150 m per microsecond of pulse), running outward from its range. Returns fall off as the fourth power of range, and sensitivity time control (STC) turns the gain up with range until the scope's flat.
The phosphor has two parts, after the P7 radar tube: a short blue-white flash at the sweep's leading edge and a long yellow-green afterglow, with P19 orange and a green tube as options. The decay is timed per bearing on the CPU in double precision, so it's exact at any frame rate and the GPU only touches the wedge the antenna just swept.
So without anything being drawn, far ships come out as wide arcs and near ones short, the trail's brightest just behind the sweep, sea clutter crowds the centre, rain drifts through as speckled cells, a coast facing the radar is a bright edge with the land behind it in shadow, and moving contacts leave a plot of their track in their fading paints. Audio onsets can fire interference spokes and, in the source, sudden contacts just ahead of the sweep.
- A source (a synthetic sea) and an Over effect (the clip is the sea) in one download
- Every bearing painted exactly once a rotation at any frame rate: the swept wedge, not a line per frame
- Point targets paint arcs as wide as the two-way beam and streaks c tau / 2 long, with an optional sidelobe pattern
- The radar equation's R to the minus four, with STC from off to flat
- A two-component phosphor (P7 blue-white flash and yellow-green afterglow, P19, green) with the decay exact in double precision
- Sea clutter, rain, noise, coast shadow and moving contacts in the source; the clip's brightest channel as reflectivity in the Over
- Audio onsets as interference spokes and sudden contacts
- Universal macOS bundles and Windows x64 DLLs
Where it stands
v0.1.0, and early days. It hasn't been loaded into Resolume on macOS yet. On Windows both plugins load, register and render in Resolume Arena 7.27.1 on software rendering (no GPU, no sound device), with every parameter as declared. The turning sweep keeps the test's noise floor high, so about half the controls read inconclusive there, though none read dead. The scope is measured offline, by a harness driving the real plugins: a point target's arc and streak come out the width and length the beam and pulse say they should, every bearing is painted once a rotation at whole, fractional and jittered frame rates, returns fall as range to the minus four and flatten under STC, and the phosphor holds its two-term decay. It catches eleven models broken on purpose and one-character sabotages of its own shaders, and all 43 parameters change the picture. A few things are simplified: the phosphor's time constants are stretched to video rates (a real P7's afterglow decays as a power law, this one as an exponential), land and clutter blur with beam and pulse rather than getting brighter, and the synthetic sea is made to look right, not measured. The macOS build is signed and notarised. There's a user guide and a browser demo, but no presets and no OpenFX port. Try it in your own rig before you trust it in a show.
Watch it running
Nothing loads from YouTube until you press play.Watch it there instead