Dynamic Objects falling through the ground

Questions
1

Objects fall through the ground, which should not be the case.
Below is the code that you can also see in the playground. Seems like I am missing something obvious, but after hours of looking into it, I don’t understand what is the problem. Please help.

const scene = new BABYLON.Scene(engine);
  scene.enablePhysics(new BABYLON.Vector3(0, -1, 0), new BABYLON.HavokPlugin());


// Camera 
const camera = new BABYLON.FreeCamera("camera1", new BABYLON.Vector3(0, 1, -4), scene);

camera.attachControl(canvas, true);

// Light
new BABYLON.HemisphericLight("light", new BABYLON.Vector3(1, 1, 0), scene);


// Ground
const ground = BABYLON.MeshBuilder.CreateGround("ground", { width: 100, height: 20 }, scene);
const groundAggregate = new BABYLON.PhysicsAggregate(ground, BABYLON.PhysicsShapeType.BOX, { mass: 0 }, scene);


// Cart
const cartMesh = BABYLON.MeshBuilder.CreateBox("cart", { height: 0.05, width: 0.4, length: 0.001 });
cartMesh.position = new BABYLON.Vector3(0, 1, 0);

const cartBody = new BABYLON.PhysicsBody(cartMesh, BABYLON.PhysicsMotionType.DYNAMIC, false, scene);
cartBody.setMassProperties({
  mass: 1,
});

// Pendulum 
const pendulumPivot = new BABYLON.TransformNode("pivot", scene);
pendulumPivot.rotation.z = 60 * Math.PI / 180; // Initial angle
pendulumPivot.parent = cartMesh;
const pendumpivotAggregate = new BABYLON.PhysicsAggregate(pendulumPivot, BABYLON.PhysicsShapeType.BOX, { mass: 0 }, scene)

const pendulumRod = BABYLON.MeshBuilder.CreateCylinder("rod", { height: 0.5, diameter: 0.02 }, scene);
pendulumRod.position = new BABYLON.Vector3(0, 0.25, 0); // Offset for pivot
pendulumRod.parent = pendulumPivot;

const pendulumBody = new BABYLON.PhysicsBody(pendulumRod, BABYLON.PhysicsMotionType.DYNAMIC, { mass: 2 }, scene);

return scene;
2

Cc @Cedric

3

pendulumBody and cartBody are just bodies, without a shape. No shape = no collision.
Create and attach a shape or use an agregate.
For linking 2bodies together, use a constraint.
Also, thanks for using a playground for sharing your code with use: click the save button and copy/paste the link.

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