three.js - focus camera on THREE.Geometry vertices - three.js

I want to focus the camera on THREE.Geometry, one vertex at a time and
Transition the camera to the next vertex of the same Geometry
How should i accomplish 1 & 2?

I created a fiddle.
http://jsfiddle.net/5oajajpd/
the function move camera goes through each vertex and sets the camera position. To transition this with animation you can set the x,y, and z properties through the jquery animate function, or your animation lib of choice.
The move camera function is triggered by an interval. In this sphere example it will spiral around and around the sphere forever.
var i = 0;
function moveCamera() {
var point = mesh.geometry.vertices[i];
var coeff = 1 + altitude / rad;
camera.position.x = point.x * coeff;
camera.position.y = point.y * coeff;
camera.position.z = point.z * coeff;
camera.lookAt(mesh.position);
i++;
if (i > mesh.geometry.vertices.length) {
i = 0;
}
}

Related

How can i zoom in to a raycaster selection?

I wonder how can i zoom in to mouse selection with ThreeJs, i'm using raycaster for selecting the model areas but something isn't working when i click on areas - as you can see in My Example (thanks to Mugen87) , my goal is to zoom into faces when i click on them... i've added the following function :
function onClick(event) {
mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;
raycaster.setFromCamera(mouse, camera);
intersects = raycaster.intersectObject( mesh, false, intersects );
if(mesh.type!= 'Mesh' || !intersects.length){
return
}
var n = intersects[ 0 ].face.normal.clone();
n.multiplyScalar(30);
n.add(intersects[ 0 ].point);
var p = intersects[ 0 ].point;
camera.position.copy(n);
camera.lookAt(p);
}
When i click outside the model - it's not keeping the position and it's spinning ...
That's because you're using OrbitControls, which pretty much takes over your camera and assigns its position and rotation once per frame. When you try to set its position manually, OrbitControls overrides anything you did.
The solution is to make your controls variable global. Then when you're ready to take over the camera position, set controls.enabled = false; in the onClick() function. Then when you're ready to return to the regular controls, set controls.enabled = true;
https://threejs.org/docs/#examples/en/controls/OrbitControls.enabled

three.js: Limiting camera's rotation

I'm working with three.js, attempting to model a real world camera. As such, I'd like to limit its axis of rotation to 90 degrees along x and y axises.
Is there a simply way to do this? My current code isn't working particularly well (and goes crazy when you attempt to move the camera past the X and Y boundaries simultaneously)
if(xRot != null && xRot != undefined){
camera.rotateX(xRot);
}
if(yRot != null && yRot != undefined){
camera.rotateY(yRot);
}
if(camera.rotation.x < minCameraRotX){
camera.rotation.x = minCameraRotX;
}else if (camera.rotation.x > maxCameraRotX){
camera.rotation.x = maxCameraRotX;
}
if(camera.rotation.y < minCameraRotY){
camera.rotation.y = minCameraRotY;
}else if(camera.rotation.y > maxCameraRotY){
camera.rotation.y = maxCameraRotY;
}
Any advice would be greatly appreciated!!!
I actually managed to find a solution by checking some of the existing code in a Three.js demo for a library called PointerLock. The idea is to actually stack multiple objects inside each other: start with an object that moves horizontally (the yaw object), place another object inside the yaw object that moves vertically (the pitch object), and then place the actual camera inside the pitch object.
Then, you only rotate the outside objects (yaw and pitch) along their respective axises, so if you rotate both, they'll self-correct. For example, if you rotate the yaw 45 degrees along the y-axis (making it turn to the right) and then rotate the pitch 45 degrees (making it turn downward), the pitch will go 45 degrees downward from the yaw's already rotated position.
Given that the camera is inside both, it just points wherever the yaw and pitch direct it.
Here is the code
/*
* CAMERA SETUP
*
* Root object is a Yaw object (which controls horizontal movements)
* Yaw object contains a Pitch object (which controls vertical movement)
* Pitch object contains camera (which allows scene to be viewed)
*
* Entire setup works like an airplane with a
* camera embedded in the propellor...
*
*/
// Yaw Object
var yawObject = new THREE.Object3D();
// Pitch Object
var pitchObject = new THREE.Object3D();
// Camera Object
var camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
// Max Camera angles (in radians)
var minCameraRotX = 0.5;
var maxCameraRotX = 0.5;
var minCameraRotY = 1;
var maxCameraRotY = 1;
// Setup
yawObject.add( pitchObject );
pitchObject.add( camera );
scene.add(yawObject);
...
var rotateCamera = function(xRot, yRot, zRot){
yawObject.rotation.y += yRot;
pitchObject.rotation.x += xRot;
// Enforce X-axis boundaries (rotates around y-axis)
yawObject.rotation.y = Math.max( minCameraRotY, Math.min( maxCameraRotY, yawObject.rotation.y ) );
// Enforce Y-axis boundaries (rotates around x-axis)
pitchObject.rotation.x = Math.max( minCameraRotX, Math.min( maxCameraRotX, pitchObject.rotation.x ) );
}
Here is the source code I referenced: https://github.com/mrdoob/three.js/blob/acda8a7c8f90ce9b71088e903d8dd029e229678e/examples/js/controls/PointerLockControls.js
Also, this is sort of cheesy, but this little plane cartoon helped me visual exactly what was going on in my setup

Why isn't my raycast intersecting anything?

I have this code, designed to find the mesh the user is clicking on:
// scene and camera are defined outside of this code
var mousePoint = new THREE.Vector2();
var raycaster = new THREE.Raycaster();
var intersections;
function onClick(event) {
mousePoint.x = event.clientX;
mousePoint.y = event.clientY;
raycaster.setFromCamera(mousePoint, camera);
intersections = raycaster.intersectObjects(
scene.children);
}
Yet every time I click, intersections comes back as an empty array, with nothing getting intersected. What am I doing wrong?
From the three.js documentation for Raycaster (emphasis mine):
.setFromCamera ( coords, camera )
coords — 2D coordinates of the mouse, in normalized device coordinates (NDC)---X and Y components should be between -1 and 1.
camera — camera from which the ray should originate
Updates the ray with a new origin and direction.
Therefore, when setting the coordinates of mousePoint, instead of setting x and y directly to event.clientX and event.clientY, they should be converted to this coordinate space:
// calculate mouse position in normalized device coordinates
// (-1 to +1) for both components
mousePoint.x = (event.clientX / window.innerWidth) * 2 - 1;
mousePoint.y = (event.clientY / window.innerHeight) * -2 + 1;

How to move the camera in three.js?

there,how can I move my camera in three.js? I mean than,scene I have a 'road',for instance,I have make a model of many roads in blender and I want to load it in three.js,and I want to move the camera along the road,so what can I do? can you give some simple code? Thank you.
You could set a clock and update the camera's position and lookAt every refresh.
var clock = new THREE.Clock();
var increment;
function animate() {
delta = clock.getDelta();
increment += delta;
// moves camera parallel to x axis
camera.position.x += increment;
camera.position.y = 100;
camera.position.z = 200;
render();
}
Or you could try using TWEEN.js.

Mouse / Canvas X, Y to Three.js World X, Y, Z

I've searched around for an example that matches my use case but cannot find one. I'm trying to convert screen mouse co-ordinates into 3D world co-ordinates taking into account the camera.
Solutions I've found all do ray intersection to achieve object picking.
What I am trying to do is position the center of a Three.js object at the co-ordinates that the mouse is currently "over".
My camera is at x:0, y:0, z:500 (although it will move during the simulation) and all my objects are at z = 0 with varying x and y values so I need to know the world X, Y based on assuming a z = 0 for the object that will follow the mouse position.
This question looks like a similar issue but doesn't have a solution: Getting coordinates of the mouse in relation to 3D space in THREE.js
Given the mouse position on screen with a range of "top-left = 0, 0 | bottom-right = window.innerWidth, window.innerHeight", can anyone provide a solution to move a Three.js object to the mouse co-ordinates along z = 0?
You do not need to have any objects in your scene to do this.
You already know the camera position.
Using vector.unproject( camera ) you can get a ray pointing in the direction you want.
You just need to extend that ray, from the camera position, until the z-coordinate of the tip of the ray is zero.
You can do that like so:
var vec = new THREE.Vector3(); // create once and reuse
var pos = new THREE.Vector3(); // create once and reuse
vec.set(
( event.clientX / window.innerWidth ) * 2 - 1,
- ( event.clientY / window.innerHeight ) * 2 + 1,
0.5 );
vec.unproject( camera );
vec.sub( camera.position ).normalize();
var distance = - camera.position.z / vec.z;
pos.copy( camera.position ).add( vec.multiplyScalar( distance ) );
The variable pos is the position of the point in 3D space, "under the mouse", and in the plane z=0.
EDIT: If you need the point "under the mouse" and in the plane z = targetZ, replace the distance computation with:
var distance = ( targetZ - camera.position.z ) / vec.z;
three.js r.98
This worked for me when using an orthographic camera
let vector = new THREE.Vector3();
vector.set(
(event.clientX / window.innerWidth) * 2 - 1,
- (event.clientY / window.innerHeight) * 2 + 1,
0
);
vector.unproject(camera);
WebGL three.js r.89
In r.58 this code works for me:
var planeZ = new THREE.Plane(new THREE.Vector3(0, 0, 1), 0);
var mv = new THREE.Vector3(
(event.clientX / window.innerWidth) * 2 - 1,
-(event.clientY / window.innerHeight) * 2 + 1,
0.5 );
var raycaster = projector.pickingRay(mv, camera);
var pos = raycaster.ray.intersectPlane(planeZ);
console.log("x: " + pos.x + ", y: " + pos.y);
Below is an ES6 class I wrote based on WestLangley's reply, which works perfectly for me in THREE.js r77.
Note that it assumes your render viewport takes up your entire browser viewport.
class CProjectMousePosToXYPlaneHelper
{
constructor()
{
this.m_vPos = new THREE.Vector3();
this.m_vDir = new THREE.Vector3();
}
Compute( nMouseX, nMouseY, Camera, vOutPos )
{
let vPos = this.m_vPos;
let vDir = this.m_vDir;
vPos.set(
-1.0 + 2.0 * nMouseX / window.innerWidth,
-1.0 + 2.0 * nMouseY / window.innerHeight,
0.5
).unproject( Camera );
// Calculate a unit vector from the camera to the projected position
vDir.copy( vPos ).sub( Camera.position ).normalize();
// Project onto z=0
let flDistance = -Camera.position.z / vDir.z;
vOutPos.copy( Camera.position ).add( vDir.multiplyScalar( flDistance ) );
}
}
You can use the class like this:
// Instantiate the helper and output pos once.
let Helper = new CProjectMousePosToXYPlaneHelper();
let vProjectedMousePos = new THREE.Vector3();
...
// In your event handler/tick function, do the projection.
Helper.Compute( e.clientX, e.clientY, Camera, vProjectedMousePos );
vProjectedMousePos now contains the projected mouse position on the z=0 plane.
to get the mouse coordinates of a 3d object use projectVector:
var width = 640, height = 480;
var widthHalf = width / 2, heightHalf = height / 2;
var projector = new THREE.Projector();
var vector = projector.projectVector( object.matrixWorld.getPosition().clone(), camera );
vector.x = ( vector.x * widthHalf ) + widthHalf;
vector.y = - ( vector.y * heightHalf ) + heightHalf;
to get the three.js 3D coordinates that relate to specific mouse coordinates, use the opposite, unprojectVector:
var elem = renderer.domElement,
boundingRect = elem.getBoundingClientRect(),
x = (event.clientX - boundingRect.left) * (elem.width / boundingRect.width),
y = (event.clientY - boundingRect.top) * (elem.height / boundingRect.height);
var vector = new THREE.Vector3(
( x / WIDTH ) * 2 - 1,
- ( y / HEIGHT ) * 2 + 1,
0.5
);
projector.unprojectVector( vector, camera );
var ray = new THREE.Ray( camera.position, vector.subSelf( camera.position ).normalize() );
var intersects = ray.intersectObjects( scene.children );
There is a great example here. However, to use project vector, there must be an object where the user clicked. intersects will be an array of all objects at the location of the mouse, regardless of their depth.
I had a canvas that was smaller than my full window, and needed to determine the world coordinates of a click:
// get the position of a canvas event in world coords
function getWorldCoords(e) {
// get x,y coords into canvas where click occurred
var rect = canvas.getBoundingClientRect(),
x = e.clientX - rect.left,
y = e.clientY - rect.top;
// convert x,y to clip space; coords from top left, clockwise:
// (-1,1), (1,1), (-1,-1), (1, -1)
var mouse = new THREE.Vector3();
mouse.x = ( (x / canvas.clientWidth ) * 2) - 1;
mouse.y = (-(y / canvas.clientHeight) * 2) + 1;
mouse.z = 0.5; // set to z position of mesh objects
// reverse projection from 3D to screen
mouse.unproject(camera);
// convert from point to a direction
mouse.sub(camera.position).normalize();
// scale the projected ray
var distance = -camera.position.z / mouse.z,
scaled = mouse.multiplyScalar(distance),
coords = camera.position.clone().add(scaled);
return coords;
}
var canvas = renderer.domElement;
canvas.addEventListener('click', getWorldCoords);
Here's an example. Click the same region of the donut before and after sliding and you'll find the coords remain constant (check the browser console):
// three.js boilerplate
var container = document.querySelector('body'),
w = container.clientWidth,
h = container.clientHeight,
scene = new THREE.Scene(),
camera = new THREE.PerspectiveCamera(75, w/h, 0.001, 100),
controls = new THREE.MapControls(camera, container),
renderConfig = {antialias: true, alpha: true},
renderer = new THREE.WebGLRenderer(renderConfig);
controls.panSpeed = 0.4;
camera.position.set(0, 0, -10);
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(w, h);
container.appendChild(renderer.domElement);
window.addEventListener('resize', function() {
w = container.clientWidth;
h = container.clientHeight;
camera.aspect = w/h;
camera.updateProjectionMatrix();
renderer.setSize(w, h);
})
function render() {
requestAnimationFrame(render);
renderer.render(scene, camera);
controls.update();
}
// draw some geometries
var geometry = new THREE.TorusGeometry( 10, 3, 16, 100, );
var material = new THREE.MeshNormalMaterial( { color: 0xffff00, } );
var torus = new THREE.Mesh( geometry, material, );
scene.add( torus );
// convert click coords to world space
// get the position of a canvas event in world coords
function getWorldCoords(e) {
// get x,y coords into canvas where click occurred
var rect = canvas.getBoundingClientRect(),
x = e.clientX - rect.left,
y = e.clientY - rect.top;
// convert x,y to clip space; coords from top left, clockwise:
// (-1,1), (1,1), (-1,-1), (1, -1)
var mouse = new THREE.Vector3();
mouse.x = ( (x / canvas.clientWidth ) * 2) - 1;
mouse.y = (-(y / canvas.clientHeight) * 2) + 1;
mouse.z = 0.0; // set to z position of mesh objects
// reverse projection from 3D to screen
mouse.unproject(camera);
// convert from point to a direction
mouse.sub(camera.position).normalize();
// scale the projected ray
var distance = -camera.position.z / mouse.z,
scaled = mouse.multiplyScalar(distance),
coords = camera.position.clone().add(scaled);
console.log(mouse, coords.x, coords.y, coords.z);
}
var canvas = renderer.domElement;
canvas.addEventListener('click', getWorldCoords);
render();
html,
body {
width: 100%;
height: 100%;
background: #000;
}
body {
margin: 0;
overflow: hidden;
}
canvas {
width: 100%;
height: 100%;
}
<script src='https://cdnjs.cloudflare.com/ajax/libs/three.js/97/three.min.js'></script>
<script src=' https://threejs.org/examples/js/controls/MapControls.js'></script>
ThreeJS is slowly mowing away from Projector.(Un)ProjectVector and the solution with projector.pickingRay() doesn't work anymore, just finished updating my own code.. so the most recent working version should be as follow:
var rayVector = new THREE.Vector3(0, 0, 0.5);
var camera = new THREE.PerspectiveCamera(fov,this.offsetWidth/this.offsetHeight,0.1,farFrustum);
var raycaster = new THREE.Raycaster();
var scene = new THREE.Scene();
//...
function intersectObjects(x, y, planeOnly) {
rayVector.set(((x/this.offsetWidth)*2-1), (1-(y/this.offsetHeight)*2), 1).unproject(camera);
raycaster.set(camera.position, rayVector.sub(camera.position ).normalize());
var intersects = raycaster.intersectObjects(scene.children);
return intersects;
}
For those using #react-three/fiber (aka r3f and react-three-fiber), I found this discussion and it's associated code samples by Matt Rossman helpful. In particular, many examples using the methods above are for simple orthographic views, not for when OrbitControls are in play.
Discussion: https://github.com/pmndrs/react-three-fiber/discussions/857
Simple example using Matt's technique: https://codesandbox.io/s/r3f-mouse-to-world-elh73?file=/src/index.js
More generalizable example: https://codesandbox.io/s/react-three-draggable-cxu37?file=/src/App.js
Here is my take at creating an es6 class out of it. Working with Three.js r83. The method of using rayCaster comes from mrdoob here: Three.js Projector and Ray objects
export default class RaycasterHelper
{
constructor (camera, scene) {
this.camera = camera
this.scene = scene
this.rayCaster = new THREE.Raycaster()
this.tapPos3D = new THREE.Vector3()
this.getIntersectsFromTap = this.getIntersectsFromTap.bind(this)
}
// objects arg below needs to be an array of Three objects in the scene
getIntersectsFromTap (tapX, tapY, objects) {
this.tapPos3D.set((tapX / window.innerWidth) * 2 - 1, -(tapY /
window.innerHeight) * 2 + 1, 0.5) // z = 0.5 important!
this.tapPos3D.unproject(this.camera)
this.rayCaster.set(this.camera.position,
this.tapPos3D.sub(this.camera.position).normalize())
return this.rayCaster.intersectObjects(objects, false)
}
}
You would use it like this if you wanted to check against all your objects in the scene for hits. I made the recursive flag false above because for my uses I did not need it to be.
var helper = new RaycasterHelper(camera, scene)
var intersects = helper.getIntersectsFromTap(tapX, tapY,
this.scene.children)
...
Although the provided answers can be useful in some scenarios, I hardly can imagine those scenarios (maybe games or animations) because they are not precise at all (guessing around target's NDC z?). You can't use those methods to unproject screen coordinates to the world ones if you know target z-plane. But for the most scenarios, you should know this plane.
For example, if you draw sphere by center (known point in model space) and radius - you need to get radius as delta of unprojected mouse coordinates - but you can't! With all due respect #WestLangley's method with targetZ doesn't work, it gives incorrect results (I can provide jsfiddle if needed). Another example - you need to set orbit controls target by mouse double click, but without "real" raycasting with scene objects (when you have nothing to pick).
The solution for me is to just create the virtual plane in target point along z-axis and use raycasting with this plane afterward. Target point can be current orbit controls target or vertex of object you need to draw step by step in existing model space etc. This works perfectly and it is simple (example in typescript):
screenToWorld(v2D: THREE.Vector2, camera: THREE.PerspectiveCamera = null, target: THREE.Vector3 = null): THREE.Vector3 {
const self = this;
const vNdc = self.toNdc(v2D);
return self.ndcToWorld(vNdc, camera, target);
}
//get normalized device cartesian coordinates (NDC) with center (0, 0) and ranging from (-1, -1) to (1, 1)
toNdc(v: THREE.Vector2): THREE.Vector2 {
const self = this;
const canvasEl = self.renderers.WebGL.domElement;
const bounds = canvasEl.getBoundingClientRect();
let x = v.x - bounds.left;
let y = v.y - bounds.top;
x = (x / bounds.width) * 2 - 1;
y = - (y / bounds.height) * 2 + 1;
return new THREE.Vector2(x, y);
}
ndcToWorld(vNdc: THREE.Vector2, camera: THREE.PerspectiveCamera = null, target: THREE.Vector3 = null): THREE.Vector3 {
const self = this;
if (!camera) {
camera = self.camera;
}
if (!target) {
target = self.getTarget();
}
const position = camera.position.clone();
const origin = self.scene.position.clone();
const v3D = target.clone();
self.raycaster.setFromCamera(vNdc, camera);
const normal = new THREE.Vector3(0, 0, 1);
const distance = normal.dot(origin.sub(v3D));
const plane = new THREE.Plane(normal, distance);
self.raycaster.ray.intersectPlane(plane, v3D);
return v3D;
}

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