Vehicle Physics Kit changelog

What changed in each published build, newest first. The same notes you see on the s&box package page.

build 5v0.4.1Jul 31, 2026

v0.4.1: the "new look for the tuning lab" release

A close x on the tuning lab. It runs the same toggle as the T key and the collapsed chip, so all three ways of closing the panel agree about the cursor.

The tuning lab has a new look: a near-black card with a 16px radius and a hairline border, the kit accent on the active control, and pill slider tracks with a flat accent fill. Key chips are pure white on their plate so the legend stays readable against it.
Text in the panel has a hierarchy now. The stylesheet declared no font size at all and rode the engine default; it sets 16/14/13 with real line heights.
A dial dragged to the bottom of its range still reads as a pill instead of an empty track, and the track lights up under the cursor.

The tuning lab was drawing with almost none of its intended styling. Its stylesheet carried six border shorthands with a border-style in them, which is a parse error in the engine's CSS that throws away the entire sheet. Those are gone, along with two box-shadows, an inset shorthand and a gradient fill the engine does not support.

The dials are still one long list. Grouping them behind Engine, Suspension, Tires and Brakes tabs needs real tab state, so it is a later build.

build 4v0.4.0Jul 21, 2026

Per-car Sport mode dials. A car can carry its own traction-control slip target and stability authority for Sport, so a rear-drive car that spun where Casual held can have its grip back without touching the other three. Leave them unset and Sport behaves exactly as it did.
Air attitude assist. Cars damp their pitch while airborne, so you land flat off a jump instead of nosing into the dirt. Hold the handbrake and it steps out of the way, so deliberate flips still work.

The whole roster is faster. Default peak torque goes 150 to 180 and the redline 6500 to 7800, worth about 20 percent more acceleration and top speed. Hand-tuned cars are unaffected, since per-car values still win; cars riding the class defaults get the new pace.
Reverse is no longer a crawl. The reverse speed cap goes from 4.5 to 20 m/s, about 45 mph. Every assist was re-checked at full reverse speed: stability damps reverse fishtails, and the gearbox still refuses to slam into forward until you are nearly stopped.
Chassis colliders ship slick. A bottomed-out or landing chassis no longer has its momentum eaten by friction on the body box. Grip is the tire model's job, not the chassis box's.

Wheels no longer sawtooth against the body on high-refresh monitors. The suspension offset is written on the fixed tick, so engine interpolation carries it exactly like the chassis.
A driven wheel that leaves the ground now freewheels instead of flaring to the redline. No more engine scream over every jump, no mid-air upshifts, and no landing in too tall a gear with a tire chirp.
Airborne wheels wind down at bearing-drag rates, 2 percent per second instead of 50. They no longer touch down at half road speed and brake the car for you.
The demo pad stopped mirroring ghostly white copies of the cars. The ground used a glossy default material, and the engine's reflection passes drop per-car tint, so the reflections rendered untinted. The pad ships its own matte material now.

Traction control does not act in reverse, because slip ratios read negative under reverse power. Reverse wheelspin is bounded by the drive-side omega cap instead. A TC pass is on the roadmap.

build 3v0.3.0Jul 19, 2026

Live tuning lab in the demo scene. A small T chip sits top-left from the moment you spawn; press T to expand it into the full lab: sliders for grip, drive torque, suspension stiffness, damping, travel, and brake force, plus assist presets (Casual / Sport / Sim), tire compounds (Stock / Street / Sport / Offroad), and a reset-to-stock button. Every change applies to the running car instantly, and the camera hands you the cursor while it is open.
Switch between the four cars with [ and ] (d-pad left/right on gamepad), same bindings as Vehicle Prototyping. The camera, your controls, and the tuning lab all follow along, and a key legend up top-right reminds you.
Modeled blockout cars. All four roster cars now spawn with stylized low-poly bodies and real cylindrical tires with rims instead of boxes and spheres. Visual only: the physics under them is unchanged.
The tuning lab and the cursor-yield camera seam double as working examples for your own UI.

Demo pad grown from about 200 m to about 1 km across, so you stop reaching the edge in seconds. Driving off the far edge still respawns the car.

Wheels now spin the correct way while driving (they rolled backwards before).
A car left near a stop now actually stops. No more endless creep with spinning wheels and skid noise unless you halted perfectly.
The camera's cursor-yield hook now survives hotloading. If you wire CursorModalOpen from your own UI and hotload mid-session, the kit recovers instead of throwing on the next play.

The demo keybinds use "Tune", "CyclePrev", and "CycleNext" input actions; consumer projects add them in their input settings, the README shows the exact entries.

build 2v0.2.1Jul 19, 2026

Parked demo cars now hold the handbrake and ignore input devices from the moment they spawn. Previously a one-tick window let a parked car read a live gamepad, and a resting trigger with drift reads as brake, which at a standstill engages reverse. That is why the Go-Kart could crawl backwards out of spawn.
Parked cars can no longer be nudged off their spawn marks by device noise or spawn settle.

The active car still reads your devices directly by design. Heavy gamepad trigger drift can make it creep at a standstill.

build 1v0.2.0Jul 19, 2026

First public release of the Vehicle Physics Kit, the raycast-wheel stack that powers Vehicle Prototyping.
Contact-normal suspension, slip-curve tires with a friction ellipse, and a full drivetrain with auto-clutch plus auto and sequential shifting.
Per-car assist levels (Casual, Sport, Sim), spring-arm chase camera with orbit and scroll zoom, and placeholder engine and skid audio.
Four ready-to-drive roster cars (hatch, coupe, kart, pickup) on primitive blockout bodies, no art needed to start driving.
A bundled demo scene: install the kit, open vehiclephysics_demo, press play.
Seams for making it yours: CustomBodyBuilder swaps in your own car models, InputOverride lets an AI or replay drive, CursorModalOpen plays nice with your UI.

Kart stuck-turn fix ported from upstream Vehicle Prototyping: cap-aware drive torque rolloff plus a Casual traction control floor relaxation, so turning hard under power no longer locks you into the turn.
Demo quality of life: only the car the camera follows listens to your keys, and cars driven off the pad edge respawn on their marks instead of falling forever.

The cars are ugly boxes on purpose. This is a physics library, your game brings the art.
First generation release: the core physics is proven in a shipped game, but the API surface may still move.