FirstPersonMovement in Three.js - javascript

there!
Greeting to all of you :-)
Im sorry if my question not interesting one. I start to code not long ago, so i think that my problem is somewhat primitive.
I made my 3d city with help of Three.js and Isaac Sukin book named "Game Development with Three.js".
It was an easy part.
But when i tried to add movement options i wasnt able to success.
Here is code, that work:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
body {
background-color: #ffffff;
margin: 0;
overflow: hidden;
}
</style>
</head>
<body>
<script src="http://cdnjs.cloudflare.com/ajax/libs/three.js/r57/three.min.js">
</script>
<script src="FirstPersonControls.js"></script>
<script>
var camera, scene, renderer, light;
var clock, controls;
function setup() {
document.body.style.backgroundColor = '#00BFFF';
setupThreeJS();
setupWorld();
requestAnimationFrame(function animate() {
renderer.shadowMapEnabled = true;
renderer.shadowMapSoft = true;
renderer.render(scene, camera);
controls.update(clock.getDelta());
requestAnimationFrame(animate);
});
}
function setupThreeJS() {
scene = new THREE.Scene();
clock = new THREE.Clock();
controls = new THREE.FirstPersonControls(camera);
controls.movementSpeed = 100;
controls.lookSpeed = 0.1;
var light = new THREE.DirectionalLight( 0xf6e86d, 1 );
light.position.set( 1, 3, 2 );
scene.add( light );
scene.fog = new THREE.FogExp2 (0x9db3b5, 0.002);
light.castShadow = true;
light.shadowDarkness = 0.7;
light.shadowMapWidth = 2048;
light.shadowMapHeight = 2048;
light.position.set(500, 1500, 1000);
light.shadowCameraFar = 2500;
light.shadowCameraLeft = -1000;
light.shadowCameraRight = 1000;
light.shadowCameraTop = 1000;
light.shadowCameraBottom = -1000;
camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 1, 10000);
camera.position.y = 410;
camera.position.z = 400;
camera.position.x = -55 * Math.PI / 180; // set camera position at 45 degrees down
renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
}
function setupWorld() {
// its floor
var geo = new THREE.PlaneGeometry(2500, 2500, 20, 20); // first 2 parametres its size of the plane, other 2 - split the plane into 20 x 20 grid
var mat = new THREE.MeshBasicMaterial({color: 0x228b22, overdraw: true});
var floor = new THREE.Mesh(geo, mat);
floor.receiveShadow = true;
floor.rotation.x = -90 * Math.PI / 180; // we set our plane at 90 degrees, so its lay directly under our building
scene.add(floor); // i cant understand. at first author tell that you should use mesg, but later, that you should use floor. ok, we'll see.
// building
var geometry = new THREE.CubeGeometry(1, 1, 1); // generate cube as basis for our builldings
geometry.applyMatrix(new THREE.Matrix4().makeTranslation(0, 0.5, 0)); // set geometry origins, the point around which the geometry is scaled and rotated
var material = new THREE.MeshPhongMaterial({map: THREE.ImageUtils.loadTexture('images/house.jpg'), overdraw: true}); // create material for our cube
//cloned buildings
var cityGeometry = new THREE.Geometry();
for (var i = 0; i < 300; i++) {
var building = new THREE.Mesh(geometry.clone()); // create all our buildings. clone method allow us to create objects as clones
building.position.x = Math.floor(Math.random() * 200 - 100) * 4;
building.position.z = Math.floor(Math.random() * 200 - 100) * 4;
building.scale.x = Math.random() * 50 + 10;
building.scale.y = Math.random() * building.scale.x * 8 + 8;
building.scale.z = building.scale.x;
THREE.GeometryUtils.merge(cityGeometry, building);
}
var city = new THREE.Mesh(cityGeometry, material);
city.castShadow = true;
city.receiveShadow = true;
scene.add(city);
}
setup();
</script>
</body>
</html>
Here is screen with derictory, where my firstattempt.html and FirstPersonControls.js located.
Files directory
FirstPersonControls.js was took from three.js/examples/js on github dot com.
Problem is that when opened in browser my city "lose" texture (which you can see on first screen) and no movement can be reached through keys.
Moreover, in Developer tool i see this error:
Error
I'll be very grateful for any help. I think, that may be problem in the way how i use FirstPersonControls.js ?
Please, excuse me for my bad knowledge of javascript :-(

maybe init camera before you pass it to controls
camera is of type undefined here so even if you pass it to the controls and then modify, controls dont get the "reference" to it
controls = new THREE.FirstPersonControls(camera);
put camera declaration before it like so...
camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 1, 10000);
controls = new THREE.FirstPersonControls(camera);

Related

Three.js increase box geometry from only one side

I'm new in three.js, and my first feature was to create a box geometry which can increased from only one side.
Problem : When you increase width or height of an object the two sides automatically increased.
jsFiddle Example
So i lost 1 hour, to find the good algorythm :
geometry = new THREE.BoxGeometry(strength, 200, 200);
material = new THREE.MeshBasicMaterial({
color: 0xff0000
});
mesh = new THREE.Mesh(geometry, material);
mesh.applyMatrix( new THREE.Matrix4().makeTranslation( - strength + strength / 2, 0, 0 ) );
Someone can explain me: - strength + strength / 2 (If i increase the strength by 1 the translation is only -0.5 not -1 ?)
What is the name of this sort of algorythm, where i can find good ressources to learn this purpose (beginner)?
Also, you can shift the geometry with .translate() method, thus you won't have a container object in the scene graph:
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 1, 1000);
camera.position.set(2, 3, 5);
var renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
var controls = new THREE.OrbitControls(camera, renderer.domElement);
scene.add(new THREE.GridHelper(10, 10));
var boxGeom = new THREE.BoxGeometry();
boxGeom.translate(0.5, 0.5, 0); // pivot point is shifted
var box = new THREE.Mesh(boxGeom, new THREE.MeshNormalMaterial());
scene.add(box);
var clock = new THREE.Clock();
var delta = 0;
var time = 0;
render();
function render() {
requestAnimationFrame(render);
delta = clock.getDelta();
time += delta;
box.scale.set(2.5 + Math.sin(time) * 2, 1.5, 1.5);
renderer.render(scene, camera);
}
body {
overflow: hidden;
margin: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/95/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/OrbitControls.js"></script>
Another option:
var container = new THREE.Object3D()
var boxMesh = new THREE.Mesh(new THREE.BoxGeometry(1,1,1));
boxMesh.position.set(0.5,0.5,0.5)
container.add(boxMesh)
scene.add(container)
container.scale.set(strength,200,200);
https://en.wikipedia.org/wiki/Scene_graph

Three.js keep camera behind object

The short version: How can one make a camera follow an object controlled by physics within a Three.js scene?
The long version: I'm working on a Three.js scene in which the W,A,S,D keys move a sphere along a plane. So far, however, I haven't figured out how to make the camera follow behind the sphere.
In the example below, the camera follows the sphere perfectly if one only presses the W key. However, if one presses A or D, the sphere starts to turn, and the camera is no longer behind the ball. If the sphere starts to turn, I want the camera to turn with it, so the camera is always following just behind the sphere, and is always a constant distance from the sphere. As users continue to press W, the ball will continue rolling forward relative to the camera.
In a previous scene [demo], I was able to implement this behavior by creating the sphere, adding that sphere to a group, then using the following bit of code each frame:
var relativeCameraOffset = new THREE.Vector3(0,50,200);
var cameraOffset = relativeCameraOffset.applyMatrix4(sphereGroup.matrixWorld);
camera.position.x = cameraOffset.x;
camera.position.y = cameraOffset.y;
camera.position.z = cameraOffset.z;
camera.lookAt(sphereGroup.position);
The key in the demo above was to rotate the sphere while keeping the sphereGroup unrotated, so I could compute the cameraOffset on the un-rotated sphereGroup.
In the demo below, the sphere's position is controlled by the Cannon.js physics library, which translates and rotates the sphere as forces are applied to the body. Does anyone know how I can make the camera follow behind the sphere in the scene below?
/**
* Generate a scene object with a background color
**/
function getScene() {
var scene = new THREE.Scene();
scene.background = new THREE.Color(0x111111);
return scene;
}
/**
* Generate the camera to be used in the scene. Camera args:
* [0] field of view: identifies the portion of the scene
* visible at any time (in degrees)
* [1] aspect ratio: identifies the aspect ratio of the
* scene in width/height
* [2] near clipping plane: objects closer than the near
* clipping plane are culled from the scene
* [3] far clipping plane: objects farther than the far
* clipping plane are culled from the scene
**/
function getCamera() {
var aspectRatio = window.innerWidth / window.innerHeight;
var camera = new THREE.PerspectiveCamera(75, aspectRatio, 0.1, 10000);
camera.position.set(0, 2000, -5000);
camera.lookAt(scene.position);
return camera;
}
/**
* Generate the light to be used in the scene. Light args:
* [0]: Hexadecimal color of the light
* [1]: Numeric value of the light's strength/intensity
* [2]: The distance from the light where the intensity is 0
* #param {obj} scene: the current scene object
**/
function getLight(scene) {
var light = new THREE.PointLight( 0xffffff, 0.6, 0, 0 )
light.position.set( -2000, 1000, -2100 );
scene.add( light );
var light = new THREE.PointLight( 0xffffff, 0.15, 0, 0 )
light.position.set( -190, 275, -1801 );
light.castShadow = true;
scene.add( light );
// create some ambient light for the scene
var ambientLight = new THREE.AmbientLight(0xffffff, 0.8);
scene.add(ambientLight);
return light;
}
/**
* Generate the renderer to be used in the scene
**/
function getRenderer() {
// Create the canvas with a renderer
var renderer = new THREE.WebGLRenderer({antialias: true});
// Add support for retina displays
renderer.setPixelRatio(window.devicePixelRatio);
// Specify the size of the canvas
renderer.setSize(window.innerWidth, window.innerHeight);
// Enable shadows
renderer.shadowMap.enabled = true;
// Specify the shadow type; default = THREE.PCFShadowMap
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
// Add the canvas to the DOM
document.body.appendChild(renderer.domElement);
return renderer;
}
/**
* Generate the controls to be used in the scene
* #param {obj} camera: the three.js camera for the scene
* #param {obj} renderer: the three.js renderer for the scene
**/
function getControls(camera, renderer) {
var controls = new THREE.TrackballControls(camera, renderer.domElement);
controls.zoomSpeed = 0.4;
controls.panSpeed = 0.4;
return controls;
}
/**
* Get stats
**/
function getStats() {
stats = new Stats();
stats.domElement.style.position = 'absolute';
stats.domElement.style.top = '0px';
stats.domElement.style.right = '0px';
document.body.appendChild( stats.domElement );
return stats;
}
/**
* Get grass
**/
function getGrass() {
var texture = loader.load('http://4.bp.blogspot.com/-JiJEc7lH1Is/UHJs3kn261I/AAAAAAAADYA/gQRAxHK2q_w/s1600/tileable_old_school_video_game_grass.jpg');
texture.wrapS = texture.wrapT = THREE.RepeatWrapping;
texture.repeat.set(10, 10);
var material = new THREE.MeshLambertMaterial({
map: texture,
side: THREE.DoubleSide,
});
return material;
}
function getPlanes(scene, loader) {
var planes = [];
var material = getGrass();
[ [4000, 2000, 0, 0, -1000, 0] ].map(function(p) {
var geometry = new THREE.PlaneGeometry(p[0], p[1]);
var plane = new THREE.Mesh(geometry, material);
plane.position.x = p[2];
plane.position.y = p[3];
plane.position.z = p[4];
plane.rotation.y = p[5];
plane.rotation.x = Math.PI / 2;
plane.receiveShadow = true;
planes.push(plane);
scene.add(plane);
})
return planes;
}
/**
* Add background
**/
function getBackground(scene, loader) {
var imagePrefix = 'sky-parts/';
var directions = ['right', 'left', 'top', 'bottom', 'front', 'back'];
var imageSuffix = '.bmp';
var geometry = new THREE.BoxGeometry( 4000, 4000, 4000 );
// Add each of the images for the background cube
var materialArray = [];
for (var i = 0; i < 6; i++)
materialArray.push( new THREE.MeshBasicMaterial({
//map: loader.load(imagePrefix + directions[i] + imageSuffix),
color: 0xff0000,
side: THREE.BackSide
}));
var sky = new THREE.Mesh( geometry, materialArray );
scene.add(sky);
return sky;
}
/**
* Add a character
**/
function getSphere(scene) {
var geometry = new THREE.SphereGeometry( 30, 12, 9 );
var material = new THREE.MeshPhongMaterial({
color: 0xd0901d,
emissive: 0xaa0000,
side: THREE.DoubleSide,
flatShading: true
});
var sphere = new THREE.Mesh( geometry, material );
// allow the sphere to cast a shadow
sphere.castShadow = true;
sphere.receiveShadow = false;
// create a group for translations and rotations
var sphereGroup = new THREE.Group();
sphereGroup.add(sphere)
sphereGroup.castShadow = true;
sphereGroup.receiveShadow = false;
scene.add(sphereGroup);
return [sphere, sphereGroup];
}
/**
* Initialize physics engine
**/
function getPhysics() {
world = new CANNON.World();
world.gravity.set(0, -400, 0); // earth = -9.82 m/s
world.broadphase = new CANNON.NaiveBroadphase();
world.broadphase.useBoundingBoxes = true;
var solver = new CANNON.GSSolver();
solver.iterations = 7;
solver.tolerance = 0.1;
world.solver = solver;
world.quatNormalizeSkip = 0;
world.quatNormalizeFast = false;
world.defaultContactMaterial.contactEquationStiffness = 1e9;
world.defaultContactMaterial.contactEquationRelaxation = 4;
return world;
}
/**
* Generate the materials to be used for contacts
**/
function getPhysicsMaterial() {
var physicsMaterial = new CANNON.Material('slipperyMaterial');
var physicsContactMaterial = new CANNON.ContactMaterial(
physicsMaterial, physicsMaterial, 0.0, 0.3)
world.addContactMaterial(physicsContactMaterial);
return physicsMaterial;
}
/**
* Add objects to the world
**/
function addObjectPhysics() {
addFloorPhysics()
addSpherePhysics()
}
function addFloorPhysics() {
floors.map(function(floor) {
var q = floor.quaternion;
floorBody = new CANNON.Body({
mass: 0, // mass = 0 makes the body static
material: physicsMaterial,
shape: new CANNON.Plane(),
quaternion: new CANNON.Quaternion(-q._x, q._y, q._z, q._w)
});
world.addBody(floorBody);
})
}
function addSpherePhysics() {
sphereBody = new CANNON.Body({
mass: 1,
material: physicsMaterial,
shape: new CANNON.Sphere(30),
linearDamping: 0.5,
position: new CANNON.Vec3(1000, 500, -2000)
});
world.addBody(sphereBody);
}
/**
* Store all currently pressed keys & handle window resize
**/
function addListeners() {
window.addEventListener('keydown', function(e) {
pressed[e.key.toUpperCase()] = true;
})
window.addEventListener('keyup', function(e) {
pressed[e.key.toUpperCase()] = false;
})
window.addEventListener('resize', function(e) {
windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
if (typeof(controls) != 'undefined') controls.handleResize();
})
}
/**
* Update the sphere's position
**/
function moveSphere() {
var delta = clock.getDelta(); // seconds
var moveDistance = 500 * delta; // n pixels per second
var rotateAngle = Math.PI / 2 * delta; // 90 deg per second
// move forwards, backwards, left, or right
if (pressed['W'] || pressed['ARROWUP']) {
sphereBody.velocity.z += moveDistance;
}
if (pressed['S'] || pressed['ARROWDOWN']) {
sphereBody.velocity.z -= moveDistance;
}
if (pressed['A'] || pressed['ARROWLEFT']) {
sphereBody.velocity.x += moveDistance;
}
if (pressed['D'] || pressed['ARROWRIGHT']) {
sphereBody.velocity.x -= moveDistance;
}
}
/**
* Follow the sphere
**/
function moveCamera() {
camera.position.x = sphereBody.position.x + 0;
camera.position.y = sphereBody.position.y + 50;
camera.position.z = sphereBody.position.z + -200;
camera.lookAt(sphereGroup.position);
}
function updatePhysics() {
world.step(1/60);
sphereGroup.position.copy(sphereBody.position);
sphereGroup.quaternion.copy(sphereBody.quaternion);
}
// Render loop
function render() {
requestAnimationFrame(render);
renderer.render(scene, camera);
moveSphere();
updatePhysics();
if (typeof(controls) === 'undefined') moveCamera();
if (typeof(controls) !== 'undefined') controls.update();
if (typeof(stats) !== 'undefined') stats.update();
};
// state
var pressed = {};
var clock = new THREE.Clock();
// globals
var scene = getScene();
var camera = getCamera();
var light = getLight(scene);
var renderer = getRenderer();
var world = getPhysics();
var physicsMaterial = getPhysicsMaterial();
//var stats = getStats();
//var controls = getControls(camera, renderer);
// global body references
var sphereBody, floorBody;
// add meshes
var loader = new THREE.TextureLoader();
var floors = getPlanes(scene, loader);
var background = getBackground(scene, loader);
var sphereData = getSphere(scene);
var sphere = sphereData[0];
var sphereGroup = sphereData[1];
addObjectPhysics();
addListeners();
render();
body { margin: 0; overflow: hidden; }
canvas { width: 100%; height: 100%; }
<script src='https://cdnjs.cloudflare.com/ajax/libs/three.js/88/three.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/cannon.js/0.6.2/cannon.js'></script>
Answers to comment questions
#jparimaa I think the most intuitive implementation would make W add forward momentum, S add backward momentum, and A and D rotate the camera around the ball. Is that possible?
#HariV The controls you link to are the ones I used in the demo without physics above. Is it possible to get that logic working with physics?
I think it's most intuitive for users if the W key always moves the ball "forward" relative to the camera
One option would be to calculate the direction between the ball and the camera and add velocity to that direction. In this case if you push the ball forward then you could rotate the camera without it affecting the velocity of the ball. Only after you press W/S after the rotation it would change the direction. I'm not sure if that is what you want but maybe this will give you some ideas.
I tried the following code (rotation is global variable initialized to 0)
function moveSphere() {
var delta = clock.getDelta(); // seconds
var moveDistance = 500 * delta; // n pixels per second
var dir = new THREE.Vector3(sphereBody.position.x, sphereBody.position.y, sphereBody.position.z);
dir.sub(camera.position).normalize(); // direction vector between the camera and the ball
if (pressed['W'] || pressed['ARROWUP']) {
sphereBody.velocity.x += moveDistance * dir.x;
sphereBody.velocity.z += moveDistance * dir.z;
}
if (pressed['S'] || pressed['ARROWDOWN']) {
sphereBody.velocity.x -= moveDistance * dir.x;
sphereBody.velocity.z -= moveDistance * dir.z;
}
}
function moveCamera() {
var delta = clock.getDelta();
var sensitivity = 150;
var rotateAngle = Math.PI / 2 * delta * sensitivity;
if (pressed['A'] || pressed['ARROWLEFT']) {
rotation -= rotateAngle;
}
if (pressed['D'] || pressed['ARROWRIGHT']) {
rotation += rotateAngle;
}
var rotZ = Math.cos(rotation)
var rotX = Math.sin(rotation)
var distance = 200;
camera.position.x = sphereBody.position.x - (distance * rotX);
camera.position.y = sphereBody.position.y + 50;
camera.position.z = sphereBody.position.z - (distance * rotZ);
camera.lookAt(sphereGroup.position);
}

Adding number of cubes in three.js

I am trying to add a number of spheres in the following example. Initially it had only three cubes, but I need to add some 10 spheres that would be equidistant from each other and would be rotating in different speeds.
My Try
var parent, renderer, scene, camera, controls;
init();
animate();
function init()
{
// renderer
renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// scene
scene = new THREE.Scene();
// camera
camera = new THREE.PerspectiveCamera(40, window.innerWidth / window.innerHeight, 1, 100);
camera.position.set(20, 20, 20);
// controls
controls = new THREE.OrbitControls(camera);
controls.minDistance = 10;
controls.maxDistance = 50;
// axes
scene.add(new THREE.AxisHelper(20));
// geometry
var geometry = new THREE.SphereGeometry(0.3, 50, 50, 0, Math.PI * 2, 0, Math.PI * 2)
// material
var material = new THREE.MeshBasicMaterial({
color: 0xffffff,
wireframe: true
});
// parent
parent = new THREE.Object3D();
scene.add(parent);
// pivots
var pivot1 = new THREE.Object3D();
var pivot2 = new THREE.Object3D();
var pivot3 = new THREE.Object3D();
var pivot4 = new THREE.Object3D();
pivot1.rotation.z = 0;
pivot2.rotation.z = 2 * Math.PI / 3;
pivot3.rotation.z = 4 * Math.PI / 3;
pivot4.rotation.z = 6 * Math.PI / 3;
parent.add(pivot1);
parent.add(pivot2);
parent.add(pivot3);
parent.add(pivot4);
// mesh
var mesh1 = new THREE.Mesh(geometry, material);
var mesh2 = new THREE.Mesh(geometry, material);
var mesh3 = new THREE.Mesh(geometry, material);
var mesh4 = new THREE.Mesh(geometry, material);
mesh1.position.y = 5;
mesh2.position.y = 5;
mesh3.position.y = 5;
mesh4.position.y = 5;
pivot1.add(mesh1);
pivot2.add(mesh2);
pivot3.add(mesh3);
pivot4.add(mesh4);
}
function animate()
{
requestAnimationFrame(animate);
parent.rotation.z += 0.01;
controls.update();
renderer.render(scene, camera);
}
Why am I not able to add more than 3 spheres into the scene? I tried to add the fourth sphere but it did not work. How can speed be accounted for here? That is: can I specify different speeds for some spheres?
Missing 4th Sphere
You specify:
pivot1.rotation.z = 0;
pivot2.rotation.z = 2 * Math.PI / 3;
pivot3.rotation.z = 4 * Math.PI / 3;
pivot4.rotation.z = 6 * Math.PI / 3;
6 * Math.PI / 3 = 2 * Math.PI
Note, three.js uses radians, therefore 2 * PI is 0 (a full revolution is the same place as no rotation.
So pivot1 and pivot4 have the same effective rotation and your 2 sphere end up in the same place in space.
Speed
You currently handle speed by mutating the z rotation on every frame.
parent.rotation.z += 0.01;
This obviously works just fine for a demo. You can speed it up by moving more per frame (or getting more frames, ie better machine or other upgrades)
parent.rotation.z += 0.04;
Now it rotates at 4 times the speed!
More Spheres
Once you get past working with counts larger than your number of fingers on a hand, I recommend getting generic with arrays. Instead of listing out pivot1, pivot2, pivot3, . . . pivot0451, generate this with a loop. (Functionally you could use ranges if you prefer).
First, we declare how many spheres to make. Then divide up the circle (2 * Math.PI radians to go around). Then for ever sphere, make a pivot. Then, for every pivot, add a mesh. And you're done.
var numberOfSpheres = 10;
var radiansPerSphere = 2 * Math.PI / numberOfSpheres;
// pivots
var pivots = [];
for (var i = 0; i < numberOfSpheres; i++) {
var pivot = new THREE.Object3D();
pivot.rotation.z = i * radiansPerSphere;
parent.add(pivot);
pivots.push(pivot);
}
var meshes = pivots.map((pivot) => {
var mesh = new THREE.Mesh(geometry, material);
mesh.position.y = 5;
pivot.add(mesh)
return mesh;
});
I implemented this at this codepen.io
Happy coding.

Moving individual particles within a Three.JS particle system

Running into a bit of a problem with Three.js. I'm currently trying to move particles within a particle system when each frame is rendered. No errors are being reported, but nothing is moving either! The example I took from the code at http://aerotwist.com/tutorials/creating-particles-with-three-js/ uses the syntax particle.position.y, but the JS console returns Cannot set property 'y' of undefined when I change the below code to mirror that. Any help or pointers on where I'm going wrong is much appreciated.
Full source code:
var scene, camera, renderer, particleCount = 0, particleSystem, particles;
init();
animate();
function init()
{
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
scene.add(camera);
camera.position.z = 5;
renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
particleCount = 1800,
particles = new THREE.Geometry();
var pMaterial = new THREE.ParticleBasicMaterial({color: 0xFFFFFF, size: 0.5});
for (var i = 0; i < particleCount; i++)
{
var pX = Math.random() * 500 - 250,
pY = Math.random() * 500 - 250,
pZ = Math.random() * 500 - 250,
particle = new THREE.Vector3(pX, pY, pZ);
particles.vertices.push(particle);
}
particleSystem = new THREE.ParticleSystem(particles, pMaterial);
scene.add(particleSystem);
}
function animate()
{
requestAnimationFrame(animate);
renderer.render(scene, camera);
var pCount = particleCount;
while (pCount--)
{
var particle = particles.vertices[pCount];
particle.y = Math.random() * 500 - 250;
particleSystem.geometry.vertices.needsUpdate = true;
}
}
It seems like you have to add particleSystem.sortParticles = true; after creating your particleSystem.
I encountered exactly the same issue in the same tutorial but, using ThreeJS 86, I needed neither the setY() nor the particleSystem.sortParticles = true; but particleSystem.geometry.verticesNeedUpdate = true; (not particleSystem.geometry.vertices.needsUpdate = true;).

Trying to aim the particles to camera while rotating and alert message on intersecting in three js?

I'm trying to create event handler on the particles, with alert message on a sphere, aiming always on the camera.
Something similar to this demo ( and making it to work on IE 9+ )
here is my code..
http://jsfiddle.net/praveenv29/cVnKV/11/
var renderer, projector;
var mouseX, mouseY, stats, container;
var objects = [];
var INTERSECTED;
var camera, scene, renderer, material, mesh, cont;
var w1 = 960;
var h1 = 700;
var halfWidth = w1 / 2;
var halfHeigth = h1 / 2;
function init() {
cont = document.createElement('div');
cont.id = "cont";
document.body.appendChild(cont);
camera = new THREE.PerspectiveCamera(75, w1 / h1, 1, 10000);
camera.position.set(90, 90, -200);
scene = new THREE.Scene();
scene.add(camera);
controls = new THREE.OrbitControls(camera);
controls = new THREE.TrackballControls(camera, cont);
controls.rotateSpeed = 0.8;
controls.zoomSpeed = 1.2;
controls.panSpeed = 2.5;
controls.noZoom = true;
controls.noPan = true;
controls.staticMoving = false;
controls.target.set(0, 0, 0);
controls.keys = [95, 90, 84];
renderer = new THREE.CanvasRenderer();
material = new THREE.MeshBasicMaterial({
color: 0x000000,
wireframe: true
});
renderer.setSize(w1, h1);
cont.appendChild(renderer.domElement);
generateGeometry();
var light = new THREE.PointLight(0xffffff);
light.position.set(10, 0, 0);
scene.add(light);
}
function animate() {
requestAnimationFrame(animate);
render();
}
function render() {
controls.update();
renderer.render(scene, camera);
}
function generateGeometry() {
var axis = new THREE.AxisHelper();
scene.add(axis);
for (var i = 0; i < 20; i++) {
var gloom = new THREE.ImageUtils.loadTexture('map_pin.png');
materialr = new THREE.MeshBasicMaterial({
map: gloom,
overdraw: true,
side: THREE.DoubleSide
});
var geometry = new THREE.PlaneGeometry(15, 15, 2, 2);
var cube = new THREE.Mesh(geometry, materialr);
cube.position.x = Math.random() * 2 - 1;
cube.position.y = Math.random() * 2 - 1;
cube.position.z = Math.random() * 2 - 1;
cube.position.normalize();
cube.position.multiplyScalar(125);
cube.rotation.x = cube.position.x / Math.PI; //57.38
cube.rotation.y = 360 / Math.PI * 2;
objects.push(cube);
scene.add(cube);
}
//earth
var texture = THREE.ImageUtils.loadTexture('world.jpg');
var materials = new THREE.MeshBasicMaterial({
map: texture,
overdraw: true
});
var cone = new THREE.SphereGeometry(120, 35, 35);
var coneMesh = new THREE.Mesh(cone, material);
coneMesh.position.y = 0;
coneMesh.rotation.set(0, 0, 0);
scene.add(coneMesh);
}
init();
animate();
It is pretty unclear what you are looking for; your demo link seems unrelated...
Are you trying to make cubes appear camera normal (always facing the camera)? If so, you'll need logic to re-orient them to re-face the camera anytime the user moves the camera view, as I see you are also setting up the TrackballControls, which actually move the camera, not the scene. This means a user can change the camera view of your scene, and items you want facing the camera need to be re-orientated. That re-orientation logic needs to be placed inside your render() function.
BTW, to get an object to always face the camera:
Define it such that when not rotated, it is facing the direction you
want;
Place the object into your scene via any method you want,
including whatever hierarchical rotations or translations you want to use to get them positioned where you want; (Note, they may not be facing
where you want at this point, but that is okay at this step);
Request from three.js that it calculate the local to world space
transformations for your scene. After that, each object's world
transformation matrix contains the concatenated rotations, and
translations that transform each object from local space to world
space.
Go into each object's local-to-world transform matrix and
replace the rotation 3x3 matrix components with the identity
transformation { [1 0 0] [0 1 0] [0 0 1] }. This effectively wipes
out the rotations in world space, making all the objects you do this
to always face the camera.

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