Introduction to Babylon.js: A Powerful Web Game Engine, undefined

Forces and Impulses

Apply physics forces to objects in your scene:

// In Physics V2, access the PhysicsBody via the aggregate

// Apply a continuous force (newtons)
sphereAggregate.body.applyForce(
    new BABYLON.Vector3(0, 0, 10), // Force direction and magnitude
    sphere.getAbsolutePosition() // Application point
);

// Apply an impulse (instantaneous force)
boxAggregate.body.applyImpulse(
    new BABYLON.Vector3(5, 0, 0), // Impulse direction and magnitude
    box.getAbsolutePosition() // Application point
);

// Set linear velocity directly
sphereAggregate.body.setLinearVelocity(new BABYLON.Vector3(0, 5, 0));

// Set angular velocity (rotation)
boxAggregate.body.setAngularVelocity(new BABYLON.Vector3(0, 2, 0));

Interactive Forces

Create user-controlled physics interactions:

// Add force on key press (Physics V2)
scene.onKeyboardObservable.add((kbInfo) => {
    if (kbInfo.type === BABYLON.KeyboardEventTypes.KEYDOWN) {
        const body = sphereAggregate.body;
        const pos = sphere.getAbsolutePosition();
        switch (kbInfo.event.key) {
            case "ArrowUp":
                body.applyImpulse(new BABYLON.Vector3(0, 0, -10), pos);
                break;
            case "ArrowDown":
                body.applyImpulse(new BABYLON.Vector3(0, 0, 10), pos);
                break;
            case "ArrowLeft":
                body.applyImpulse(new BABYLON.Vector3(-10, 0, 0), pos);
                break;
            case "ArrowRight":
                body.applyImpulse(new BABYLON.Vector3(10, 0, 0), pos);
                break;
            case " ": // Space key
                body.applyImpulse(new BABYLON.Vector3(0, 10, 0), pos);
                break;
        }
    }
});