Play & Drive Mode
Play mode turns your static 3D street design into a live, moving scene: press Start and the scene comes alive — vehicles and pedestrians animate, and if you've added a driveable vehicle you can get behind the wheel and drive it through your own design with WASD or a gamepad.
It's built for design review and storytelling. You can walk (or drive) a stakeholder through a proposed street, show what traffic feels like at street level, and get an intuitive sense of a design that a top-down plan can't convey.
Play & Drive mode is available to use today. The driving simulation, timing, and camera work end to end; the surrounding UI and the set of "playable" features are still growing, so details may change between releases.
The Play lifecycle
Play mode is presentation-only. Nothing about a play session is written back to your scene — no positions, no simulation state, no markers persist — so:
- anyone can Start it, even on a scene they can't edit (no edit permission required);
- you can't break your design by playing it — Stop returns everything exactly as it was.
The controls are:
| Control | What it does |
|---|---|
| Start | Begin the play session — the simulation clock starts at zero and every play feature springs to life. |
| Pause / Resume | Freeze and un-freeze the simulation in place. |
| Reset | Restart the current session from the top — actors jump back to their spawn points and the clock zeroes, without leaving play mode. |
| Stop | End the session and return to editing (or to the idle viewer, depending on where you started from). |
Under the hood, everything is driven by a single deterministic simulation clock. Because features position their actors as a pure function of that clock, a play session looks the same every time and at the same moment on any machine. When the physics simulation is running, the clock advances one step per completed physics sub-step — so on a slow computer you get true, smooth slow-motion rather than a stuttering scene that falls behind.
What plays
Play mode is a shared stage that several features perform on, independently:
- Driving simulation — drive a vehicle you've added (see below).
- Street traffic — the vehicles and people you placed on a Managed Street animate along their lanes.
- Traffic Replay — real anonymized sensor counts play back as animated street users.
- Race mode — an optional finish gate, crash markers, and saved best times turn a drive into a time trial.
You'll only see the Start button when the scene actually contains something playable (a driveable vehicle, a managed street with traffic, or a replay layer). An empty scene has nothing to play, so the control stays hidden.
Drive mode
Drive mode lets you pilot a physically-simulated vehicle around your scene in real time. The car has real suspension, grip, and momentum — it leans into turns, mounts curbs (or can't, depending on the vehicle), and bumps into buildings.
Add a driveable vehicle
From Add Layer, pick one of the driveable vehicles:
| Vehicle | Feel |
|---|---|
| Driveable Taxi | A full-size sedan (~Camry-sized) with real-car physics. Mounts standard curbs with momentum and reaches real-world speeds. |
| Driveable Tuk-tuk | A small three-wheeler. Nimble; can mount curbs at speed. |
| Driveable Delivery Robot | A small sidewalk bot (~Starship / Serve-sized) with a procedural body and bouncing antenna. Like the real thing, it can't climb standard 6-inch curbs. |
Adding one drops the vehicle into your scene as its own layer. You can add a driveable vehicle to any scene — a Managed Street, a geospatial scene, or a bare street template.
Drive it
Press Start. The first time you do this in a session there's a brief pause while the physics engine loads, then you take control of the car.
| Input | Action |
|---|---|
| W / A / S / D or arrow keys | Accelerate, steer, reverse |
| Space | Brake |
| R | Reset the car to its spawn point |
| C | Cycle the camera: top-down → chase → first-person |
A gamepad works too: right/left triggers for throttle and reverse, B to brake, left stick to steer, the right stick to orbit and zoom the chase camera, Y to reset, X to change camera, Start to pause, Back to stop.
Tune the vehicle
Two places let you change how the car behaves:
- Properties panel (select the vehicle layer): pick a Vehicle Preset to swap the whole mesh + physics package in one click, or hand-tune Engine Force, Brake Force, and Steer Angle. These settings save with the scene.
- Drive controls panel (top-right, appears while driving): the same three sliders, live — drag them mid-drive and feel the change immediately. It also shows a Wall / Sim clock readout so you can see the deterministic sim time next to real elapsed time.
Race mode
Add a race finish gate and drive mode becomes a time trial:
- your run is timed on the simulation clock;
- every collision drops a crash marker at the point of impact and adds a 1-second penalty;
- crossing the gate records your time, and your best time per course is saved locally so you can try to beat it.
Crash markers and best-time state are session-only in the scene (markers are stripped on Stop/Reset) — nothing pollutes your saved design.
Tips
- Match your street to reality. Vehicle speed and how a drive feels depend on your street's real dimensions — set segment widths and lengths to the true values for a believable result.
- Curbs matter. If you're studying whether a delivery robot or a car can access a space, the preset you choose reflects real curb-climbing ability — the delivery robot deliberately can't mount a standard curb.
- It's a presentation, not a save. Play mode is the right tool for a live demo or a screen recording; use the viewer's video export to capture a drive-through for a case study.