Vehicle Physics

// This example uses Ammo.js which supports advanced vehicle physics
// Note: Vehicle physics implementation depends on the physics engine used

// Create a vehicle chassis
const chassisWidth = 2;
const chassisHeight = 0.6;
const chassisLength = 4;

const chassis = BABYLON.MeshBuilder.CreateBox("chassis", {
    width: chassisWidth,
    height: chassisHeight,
    depth: chassisLength
}, scene);
chassis.position.y = 4;

// Create wheels
const wheelRadius = 0.4;
const wheelWidth = 0.3;
const wheelPositions = [
    new BABYLON.Vector3(chassisWidth/2, -chassisHeight/2, chassisLength/2 - wheelRadius), // front right
    new BABYLON.Vector3(-chassisWidth/2, -chassisHeight/2, chassisLength/2 - wheelRadius), // front left
    new BABYLON.Vector3(chassisWidth/2, -chassisHeight/2, -chassisLength/2 + wheelRadius), // rear right
    new BABYLON.Vector3(-chassisWidth/2, -chassisHeight/2, -chassisLength/2 + wheelRadius) // rear left
];

const wheels = [];
for (let i = 0; i < 4; i++) {
    const wheel = BABYLON.MeshBuilder.CreateCylinder(`wheel${i}`, {
        diameter: wheelRadius * 2,
        height: wheelWidth,
        tessellation: 24
    }, scene);
    wheel.rotation.z = Math.PI / 2; // Rotate to correct orientation
    wheel.position = chassis.position.add(wheelPositions[i]);
    wheels.push(wheel);
}

// Add physics
chassis.physicsImpostor = new BABYLON.PhysicsImpostor(
    chassis,
    BABYLON.PhysicsImpostor.BoxImpostor,
    { mass: 800, friction: 0.5, restitution: 0.2 },
    scene
);

// Configure vehicle physics (Ammo.js specific)
// Note: Implementation details vary by physics engine
if (scene.getPhysicsEngine().getPhysicsPluginName() === "AmmoJSPlugin") {
    const vehicle = new BABYLON.AmmoJSPlugin.Vehicle(chassis, scene);
    
    // Add wheels to vehicle
    for (let i = 0; i < 4; i++) {
        const isFront = i < 2;
        vehicle.addWheel(
            wheels[i],
            wheelPositions[i],
            new BABYLON.Vector3(0, -1, 0),  // Down direction
            new BABYLON.Vector3(0, 0, 1),   // Forward direction
            0.6,  // Suspension rest length
            wheelRadius,
            isFront // Steering wheel?
        );
    }
    
    // Configure vehicle properties
    vehicle.setSteeringValue(0.0);  // Initial steering
    vehicle.applyEngineForce(0.0);  // Initial engine force
    vehicle.setBrake(0.0);          // Initial brake force
    
    // Vehicle control with keyboard
    scene.onKeyboardObservable.add((kbInfo) => {
        const key = kbInfo.event.key;
        const isDown = kbInfo.type === BABYLON.KeyboardEventTypes.KEYDOWN;
        
        switch (key) {
            case "w":
                vehicle.applyEngineForce(isDown ? 1000 : 0);
                break;
            case "s":
                vehicle.applyEngineForce(isDown ? -500 : 0);
                break;
            case "a":
                vehicle.setSteeringValue(isDown ? 0.3 : 0);
                break;
            case "d":
                vehicle.setSteeringValue(isDown ? -0.3 : 0);
                break;
            case " ":
                vehicle.setBrake(isDown ? 50 : 0);
                break;
        }
    });
}