multi depth-camera fusion // Kinect + Orbbec // persistent IDs
Instant multi-cam people tracking inside TouchDesigner
Cumulus is a single .tox component that fuses your Kinect and Orbbec point clouds into one space and outputs stable, persistently-ID’d people — past the 8-body cap, past single-camera blind spots, without hand-rolling fusion code before every activation.
Every multi-person activation hits the same wall
The native ceiling
TouchDesigner’s Body Track CHOP is hard-capped at 8 tracked bodies per source — a limit inherited from the NVIDIA Maxine SDK, confirmed by a Derivative team member. Bigger crowd, bigger footprint, second camera angle? You’re on your own.
source: forum.derivative.ca — “Body Track CHOP limited to 8 bodies”The hand-rolled workaround
So teams rebuild point-cloud alignment, cropping, clustering and ID persistence from scratch — per activation. At creative-technologist rates of $1,200–$1,500/day, that’s $3,600–$7,500 of engineering before a single pixel of content exists.
and it rarely survives the next venue, camera count, or crowdThe hardware escape hatch
The dedicated-tracker route starts at $29,999 for an entry-level BlackTrax BT-1 rig — often more than an entire Starter-tier activation budget. And the one open-source alternative built for this, OpenPTrack, is officially deprecated.
BlackTrax BT-1 list price · OpenPTrack marked deprecated by its maintainers“I know people have been interested in a body tracking solution from a merged point cloud from multiple sources, but I’m not aware of any options for that right now.”
From point clouds to stable IDs in one session
Cumulus packages the pipeline Derivative’s own team points to — point-cloud fusion, then clustering — as a native C++ CHOP wrapped in a component any TD operator can drive.
Drop in the .tox
Drag one component into your existing network. Point it at the Kinect and Orbbec TOPs you already run — no new hardware, no new pipeline, no migration.
sources: kinect / orbbec point-cloud TOPsCalibrate your sources
Align each camera with per-source translate / rotate / scale controls, crop the scene to the capture volume, and mask out the bar, the DJ booth, the crowd barrier.
per-source calibration · scene crop · mask volumesStable IDs out
Downstream, your content just receives clean per-person channels — centroid, bounds, velocity, head — with IDs that hold while people cross paths and occlude each other.
centroid · bounds · velocity · head · persistent idBuilt like a spec sheet, not a promise
Everything below ships in the component today and is documented in the user guide — parameters grouped the way TouchDesigner artists expect.
Multi-camera fusionSources · per-source calibration
Fuse multiple Kinect / Orbbec point clouds into one shared space, with per-source transform, color, binning and time-delay controls. No 8-body ceiling, no single-camera blind spots.
Persistent cluster IDsTracking · validation + ghost hold
IDs survive people crossing paths and short occlusions: validation delay rejects false enters, ghost hold time bridges dropouts, match radius and velocity clamps kill ID swaps.
Scene crop & mask volumesMasking · incl. POP geometry masks
Include / exclude volumes clean up messy venues after the broad scene crop — cut out walls, furniture and staff zones, with closed POP surfaces as custom mask shapes.
1-Euro smoothingFiltering · per-output controls
Centroid, bounds, velocity and head outputs each get their own 1-Euro filter — smooth, low-lag input for your visuals without writing your own filter chain.
Built-in body simulatorSimulator · synthetic bodies
Rehearse crowd scenarios — enters, exits, groups, occlusions — with synthetic moving bodies before a single camera is plugged in. Tune the whole rig from your studio, days before load-in.
JSON presets & diagnosticsPresets · Setup · info channels
Save a tuned rig as a JSON preset and redeploy it on the next activation in minutes. Live diagnostics expose cook time, point / cluster counts and dropped-cluster metrics on show day.
parameter pages: Sources · Scene · Point Cloud · Masking · Clustering · Tracking · Filtering · Output · Simulator · Presets · Diagnostics
What solving this usually costs
Hand-building fusion, clustering and ID persistence per activation: 3–5 creative-technologist dev-days at $1,200–$1,500/day — repeated on every project, because deadline code doesn’t get reused.
per activation, before any content is builtA dedicated hardware tracker — BlackTrax’s entry BT-1 configuration — a fixed cost that has to be justified against activation budgets that often run $15K–$80K in total.
BlackTrax BT-1, entry-level configurationCumulus: a free tier to test on your own rig, with a paid license planned at roughly $50–100 at launch. One avoided dev-day already pays for it more than tenfold.
early-access founder pricing · pre-launchPre-launch pricing, said plainly
Cumulus is indie-built and about to launch. Early numbers below are the plan — waitlist members get them confirmed first, and keep them.
$0
- Test Cumulus on your own rig and cameras
- Full simulator to rehearse before you commit
- No card, no contract
~$50–100 planned at launch
- The full component: fusion, persistent IDs, masks, smoothing, presets, diagnostics
- Founder pricing locked before standard tiers arrive
- Direct line to the developer for feature requests
Joining the waitlist locks launch pricing. When the early-access cohort fills, later studios join at standard pricing — this is a one-developer product, and onboarding capacity is genuinely limited.
Questions studios actually ask
Which cameras does it support?
Kinect and Orbbec point-cloud sources are supported today, including networked Orbbec devices addressed by IP. You can mix sensor types across source blocks, each with its own calibration. More source types are on the roadmap — tell us what your rig runs when you join the waitlist.
What platform / TouchDesigner version do I need?
Cumulus ships as a Windows .tox built and tested against current official TouchDesigner builds. If your studio is pinned to a specific build, mention it when you join and we’ll confirm compatibility before you install anything.
What’s this about a native DLL?
The clustering core is a native C++ CHOP plugin (Clustering.dll) embedded inside the .tox, so there’s no separate plugin folder to manage. On managed or production machines, IT security tools may scan native DLLs at load time — the release ships with the exact DLL build and its SHA-256 hash for allowlisting and verification.
Is this skeleton tracking?
No — and that’s deliberate. Cumulus does cluster-based people tracking: per-person centroid, bounds, velocity, orientation helpers and optional head position, with persistent IDs. That’s what large-footprint interactive installations actually consume, and it’s what scales past the 8-body skeletal ceiling.
Where does the tracking data go?
Nowhere. Cumulus runs entirely inside your TouchDesigner network on your machine, processing point clouds from cameras you already own. There is no cloud step — nothing about the people at your activation leaves the building.
What do I get for joining the waitlist?
Early access before public launch, founder pricing locked (free tier + the ~$50–100 license), and launch-only email updates. No newsletter, no drip sequence.
Stop re-solving tracking before every show
Get early access to Cumulus, lock launch pricing, and put multi-cam people tracking on the shelf next to your other presets — where it belongs.