Reputation: 359
Noob Question: I'm trying to drop a ball to the floor and make it stick there or even roll over a plane. Right now it passes trough the plane. I'm not sure where I made a mistake or if I'm doing anything wrong.
var world, timeStep=1/60, scene, renderer, camera,
icosahedronBody, sphereShape, groundShape,
ground, groundBody, groundShape;
// CONSTANTS
var GRID_HELPER_SIZE = 40,
GRID_HELPER_STEP = 2,
MASS = 5;
initThree();
initCannon();
animate();
function initCannon() {
world = new CANNON.World();
world.broadphase = new CANNON.NaiveBroadphase();
sphereShape = new CANNON.Sphere();
groundShape = new CANNON.Plane();
icosahedronBody = new CANNON.Body({
mass: MASS,
});
groundBody = new CANNON.Body({
mass: 0, // mass == 0 makes the body static
});
world.solver.iterations = 10;
world.gravity.set(0,-9.8,0);
world.defaultContactMaterial.contactEquationStiffness = 1e9;
world.defaultContactMaterial.contactEquationRegularizationTime = 4;
icosahedronBody.addShape(sphereShape);
icosahedronBody.position.set(0,50,0)
icosahedronBody.linearDamping = 0.5;
world.addBody(icosahedronBody);
groundBody.addShape(groundShape);
groundBody.quaternion.setFromAxisAngle(new CANNON.Vec3(0,1,0),-Math.PI/2);
world.addBody(groundBody);
var ballContact = new CANNON.ContactMaterial( groundBody, icosahedronBody, 0.0, 0.0);
world.addContactMaterial(ballContact);
}
function initThree(){
// INITIALIZE CANVAS
scene = new THREE.Scene();
renderer = new THREE.WebGLRenderer();
camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 );
var light = new THREE.AmbientLight( 0x404040 ),
directionalLight = new THREE.DirectionalLight( 0xffffff ),
gridHelper = new THREE.GridHelper( GRID_HELPER_SIZE, GRID_HELPER_STEP );
renderer.setSize( window.innerWidth - 100 , window.innerHeight - 100 );
renderer.setClearColor( 0x757575 );
document.body.appendChild( renderer.domElement );
camera.position.set(1,25,100); // camera position to x , y , z
camera.lookAt( new THREE.Vector3() )
directionalLight.position.set( 1, 0.75, 0.5 ).normalize();
// INITIAL CANVAS
scene.add( directionalLight );
scene.add( light );
scene.add( camera );
scene.add( gridHelper );
// MATERIALS
var icoGeometry = new THREE.IcosahedronGeometry(10, 1),
icoMaterial = new THREE.MeshLambertMaterial( {color: 0xff0000} );
icosahedron = new THREE.Mesh( icoGeometry, icoMaterial );
var groundGeometry = new THREE.BoxGeometry(100 , 1, 100),
groundMaterial = new THREE.MeshLambertMaterial( {color: 0xcccccc} );
ground = new THREE.Mesh( groundGeometry, groundMaterial );
ground.receiveShadow = true;
// ADD OBJECTS TO SCENE
scene.add( icosahedron );
scene.add( ground );
}
function animate() {
requestAnimationFrame( animate );
updatePhysics();
render();
}
function updatePhysics() {
// Step the physics world
world.step(timeStep);
// Copy coordinates from Cannon.js to Three.js
icosahedron.position.copy(icosahedronBody.position);
icosahedron.quaternion.copy(icosahedronBody.quaternion);
ground.position.copy(groundBody.position);
ground.quaternion.copy(groundBody.quaternion);
}
function render() {
renderer.render( scene, camera );
}
Upvotes: 1
Views: 1522
Reputation: 2084
It appears that your CANNON.Plane
is oriented the wrong way. By default, it's normal is pointing in the Z direction, so you need to rotate it -90 degrees along the positive X axis to make its normal point in the positive Y direction (use the right hand rule):
groundBody.quaternion.setFromAxisAngle(new CANNON.Vec3(1,0,0),-Math.PI/2);
Secondly, you have to make the BoxGeometry match. Make sure its thinner along its Z axis.
var groundGeometry = new THREE.BoxGeometry(100, 100, 1),
I also note that the radius of the THREE.IcosahedronGeometry
is 10, while the radius of the CANNON.Sphere
is 1 (the default). Set its radius to 10 to match the three.js geometry:
sphereShape = new CANNON.Sphere(10);
Replace these three lines and your simulation looks like it should. Good luck!
Upvotes: 3