Babylon.js/Playground/scripts/Intersections.js

var createScene = function () {
    var scene = new BABYLON.Scene(engine);

    var camera = new BABYLON.ArcRotateCamera("Camera", 1, 0.8, 70, new BABYLON.Vector3(5, 0, 0), scene);
    camera.attachControl(canvas, true);

    // Material
    var matPlan = new BABYLON.StandardMaterial("matPlan1", scene);
    matPlan.backFaceCulling = false;
    matPlan.emissiveColor = new BABYLON.Color3(0.2, 1, 0.2);

    var matBB = new BABYLON.StandardMaterial("matBB", scene);
    matBB.emissiveColor = new BABYLON.Color3(1, 1, 1);
    matBB.wireframe = true;

    // Intersection point
    var pointToIntersect = new BABYLON.Vector3(-30, 0, 0);
    var origin = BABYLON.Mesh.CreateSphere("origin", 4, 0.3, scene);
    origin.position = pointToIntersect;
    origin.material = matPlan;

    // Create two planes
    var plan1 = BABYLON.Mesh.CreatePlane("plane1", 20, scene);
    plan1.position = new BABYLON.Vector3(13, 0, 0);
    plan1.rotation.x = -Math.PI / 4;
    plan1.material = matPlan;

    var plan2 = BABYLON.Mesh.CreatePlane("plane2", 20, scene);
    plan2.position = new BABYLON.Vector3(-13, 0, 0);
    plan2.rotation.x = -Math.PI / 4;
    plan2.material = matPlan;

    // AABB - Axis aligned bounding box
    var planAABB = BABYLON.Mesh.CreateBox("AABB", 20, scene);
    planAABB.material = matBB;
    planAABB.position = new BABYLON.Vector3(13, 0, 0);
    planAABB.scaling = new BABYLON.Vector3(1, Math.cos(Math.PI / 4), Math.cos(Math.PI / 4));

    // OBB - Object boundind box
    var planOBB = BABYLON.Mesh.CreateBox("OBB", 20, scene);
    planOBB.scaling = new BABYLON.Vector3(1, 1, 0.05);
    planOBB.parent = plan2;
    planOBB.material = matBB;

    // Balloons
    var balloon1 = BABYLON.Mesh.CreateSphere("balloon1", 10, 2.0, scene);
    var balloon2 = BABYLON.Mesh.CreateSphere("balloon2", 10, 2.0, scene);
    var balloon3 = BABYLON.Mesh.CreateSphere("balloon3", 10, 2.0, scene);
    balloon1.material = new BABYLON.StandardMaterial("matBallon", scene);
    balloon2.material = new BABYLON.StandardMaterial("matBallon", scene);
    balloon3.material = new BABYLON.StandardMaterial("matBallon", scene);

    balloon1.position = new BABYLON.Vector3(6, 5, 0);
    balloon2.position = new BABYLON.Vector3(-6, 5, 0);
    balloon3.position = new BABYLON.Vector3(-30, 5, 0);

    //Animation
    var alpha = Math.PI;
    scene.registerBeforeRender(function () {

        //Balloon 1 intersection -- Precise = false
        if (balloon1.intersectsMesh(plan1, false)) {
            balloon1.material.emissiveColor = new BABYLON.Color3(1, 0, 0);
        } else {
            balloon1.material.emissiveColor = new BABYLON.Color3(1, 1, 1);
        }

        //Balloon 2 intersection -- Precise = true
        if (balloon2.intersectsMesh(plan2, true)) {
            balloon2.material.emissiveColor = new BABYLON.Color3(1, 0, 0);
        } else {
            balloon2.material.emissiveColor = new BABYLON.Color3(1, 1, 1);
        }

        //balloon 3 intersection on single point
        if (balloon3.intersectsPoint(pointToIntersect)) {
            balloon3.material.emissiveColor = new BABYLON.Color3(1, 0, 0);
        } else {
            balloon3.material.emissiveColor = new BABYLON.Color3(1, 1, 1);
        }

        alpha += 0.01;
        balloon1.position.y += Math.cos(alpha) / 10;
        balloon2.position.y = balloon1.position.y;
        balloon3.position.y = balloon1.position.y;
    });


    return scene;
}