three.js - How to set camera position? - javascript

I'm pretty beginner in three.js and webgl programming. so I have created a box in three.js and its working fine but the problem is when I set camera position in z axis(eg: camera.position.z = 2; ) the box just disappears. could anyone explain me why is it happening and how can I properly set the position of the camera?
try uncommenting the camera.position.z = 2; in the fiddle
function init() {
var scene = new THREE.Scene();
var box = getBox(1, 1, 1);
scene.add(box);
var camera = new THREE.Camera(45, window.innerWidth/window.innerHeight, 1, 1000 );
//camera.position.z = 2;
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.getElementById("webgl").appendChild(renderer.domElement);
renderer.render(scene, camera);
}
function getBox(w, h, d) {
var geometry = new THREE.BoxGeometry(w, h, d);
var material = new THREE.MeshBasicMaterial({
color : 0x00ff00
});
var mesh = new THREE.Mesh(geometry, material);
return mesh;
}
init();

not sure if you're trying to create this scene with an orthographic camera or perspective camera, but you'll typically need to specify the camera by type (ie THREE.PerspectiveCamera(...)).
I also added a few extra lines to ensure the camera was configured correctly, namely, setting the "LookAt" point to (0,0,0) , as well as setting an actual position of the camera via the THREE.Vector3.set(...) method.
Here are my adjustments to your code:
function init() {
var scene = new THREE.Scene();
var box = getBox(1, 1, 1);
scene.add(box);
var camera = new THREE.PerspectiveCamera(70,
window.innerWidth/window.innerHeight, 0.1, 1000 ); // Specify camera type like this
camera.position.set(0,2.5,2.5); // Set position like this
camera.lookAt(new THREE.Vector3(0,0,0)); // Set look at coordinate like this
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.getElementById("webgl").appendChild(renderer.domElement);
renderer.render(scene, camera);
}
function getBox(w, h, d) {
var geometry = new THREE.BoxGeometry(w, h, d);
var material = new THREE.MeshBasicMaterial({
color : 0x00ff00
});
var mesh = new THREE.Mesh(geometry, material);
return mesh;
}
init();

Try
camera.position.set( <X> , <Y> , <Z> );
where <X> and <Z> are 2D coordinates and <Y> is height

Related

Setting the position of a text geometry?

I have looked through stack overflow and google and I have found how to CENTER a text geometry but that is not what I want to do.
I have a scene that just has a block of text that says "Buy Here!". Using the documentation in the three.js website and examples here I was able to do that after some struggling. I had some trouble finding out how to refer to that mesh since I had created the geometry inside a function, and it took hours for me to know about setting a name for it as a string so it can be accessible from different parent/child levels.
What I am NOT able to do now is to offset the text by some arbitrary number of units. I tried shifting it down by 5 units. No matter how I try to do it it isn't working. I either manage to make the text geometry disappear OR my whole scene is black.
Here is my code...
I have the basic scene setup working properly and I'll include it here but feel free to skip since I'm pretty sure this has nothing to do with the issue...
import './style.css'
import * as THREE from 'three';
import { OrbitControls } from 'https://cdn.jsdelivr.net/npm/three#0.117.0/examples/jsm/controls/OrbitControls.js';
import TWEEN from 'https://cdn.jsdelivr.net/npm/#tweenjs/tween.js#18.5.0/dist/tween.esm.js';
//BASIC SCENE SETUP
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setPixelRatio(window.devicePixelRatio);
document.body.appendChild(renderer.domElement);
//LIGHTS (POINT AND AMBIENT)
const pointLight = new THREE.PointLight(0xFFFFFF);
pointLight.position.set(5, 5, 5);
const ambientLight = new THREE.AmbientLight(0xFFFFFF);
scene.add(pointLight, ambientLight);
//RESIZE WINDOW
window.addEventListener('resize', () => {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
render();
}, false);
//ORBIT CONTROLS
const controls = new OrbitControls(camera, renderer.domElement);
controls.minDistance = 5;
controls.maxDistance = 70;
controls.enablePan = false;
controls.enableRotate = false;
controls.enableZoom = false;
controls.target.set(0,0,-1);
camera.position.setZ(25);
window.addEventListener("click", (event) => {
onClick(event);
})
window.addEventListener("mousemove", onMouseMove);
var animate = function() {
requestAnimationFrame(animate);
controls.update();
render();
TWEEN.update();
};
function render() {
renderer.render(scene, camera);
}
animate();
and here is my code for the text object....
var loaderF = new THREE.FontLoader();
loaderF.load( 'https://threejs.org/examples/fonts/optimer_regular.typeface.json', function ( font ) {
var geometry = new THREE.TextGeometry( 'Buy Here!', {
font: font,
size: 2.3,
height: 0.1,
curveSegments: 15,
bevelEnabled: true,
bevelThickness: 0.5,
bevelSize: 0.31,
bevelSegments: 7
} );
geometry.center();
var material = new THREE.MeshLambertMaterial({color: 0x686868});
var mesh = new THREE.Mesh( geometry, material );
mesh.name = "bhText"
scene.add( mesh );
mesh.userData = { URL: "http://google.com"};
} );
Here's what I have tried.....
under "var geometry ({...});" I typed....
geometry.position.setX(-5);
but the text object disappears completely so I tried
geometry.position.setX = -5;
but there was no difference so i tried taking out
geometry.center();
but it had the same results.
So then I tried using
mesh.position.x = -5;
with AND without
geometry.center();
but again, they all just make my text object disappear.
So now I tried to set the position from outside the function by typing the following code OUTSIDE of everything that is contained in
loaderF.load ('https.....', function (font){var geometry = .....})
using the reference I learned....
scene.getObjectByName("bhText").position.x(-5);
but this makes my entire scene go blank (black). So I tried variations of like
scene.getObjectByName("bhText").position.x = -5;
scene.getObjectByName("bhText").position.setX(-5);
scene.getObjectByName("bhText").position.setX = -5;
mesh.position.setX = -5;// I was pretty sure this wasn't going to work since I wasn't
//using the mesh name specifically for when it's inside something
//I can't reach because of parent-child relations
and again trying each of those with AND without
geometry.center();
but they all made my scene go black.
I just wanna move it down a couple of units. Sheesh.
Could anyone be kind enough to tell me WHERE in my code I can set the position of the text geometry? Thank you please.
I just wanna move it down a couple of units.
In this case use mesh.position.y = - 5;. Changing the x coordinate will move the mesh to the left or right. Here is a complete live example based on your code:
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
camera.position.set( 0, 0, 10 );
const renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setPixelRatio(window.devicePixelRatio);
document.body.appendChild(renderer.domElement);
const pointLight = new THREE.PointLight(0xFFFFFF);
pointLight.position.set(5, 5, 5);
const ambientLight = new THREE.AmbientLight(0xFFFFFF);
scene.add(pointLight, ambientLight);
const loader = new THREE.FontLoader();
loader.load('https://threejs.org/examples/fonts/optimer_regular.typeface.json', function(font) {
const geometry = new THREE.TextGeometry('Buy Here!', {
font: font,
size: 2,
height: 0.5
});
geometry.center();
const material = new THREE.MeshLambertMaterial({
color: 0x686868
});
const mesh = new THREE.Mesh(geometry, material);
mesh.position.y = - 1; // FIX
mesh.name = "bhText"
scene.add(mesh);
renderer.render(scene, camera);
});
body {
margin: 0;
}
<script src="https://cdn.jsdelivr.net/npm/three#0.130.1/build/three.min.js"></script>

How can I draw Letters in 3js/threeJS easily?

I have to draw letters using 3JS.
Previously I have drawed objects in Canvas with beziercurves, using a website that helped do them with the mouse.
Is there such a tool for the same job in 3JS?
I can't seem to find anything. And drawing them manually in code just seems a waste of time.
I've searched everywhere for it but nothing.
I'm using Spline Curves btw...
curve = new THREE.SplineCurve( [
new THREE.Vector2( -90, 50),
new THREE.Vector2( -150, 0),
new THREE.Vector2( -130, 50),
]);
Thanks in advance
https://threejs.org/docs/#manual/en/introduction/Creating-text
Gives different ways to draw text.
You can use TextGeometry:
var camera, scene, renderer;
init();
animate();
function init() {
camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight);
camera.position.z = 10;
scene = new THREE.Scene();
var loader = new THREE.FontLoader();
loader.load('https://unpkg.com/three#0.77.0/examples/fonts/helvetiker_regular.typeface.json', function(font) {
var geometry = new THREE.TextGeometry('Hello World', {
font: font,
size: 1,
height: 1
});
geometry.center();
var material = new THREE.MeshNormalMaterial();
var mesh = new THREE.Mesh(geometry, material);
scene.add(mesh);
});
renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
}
function animate() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r99/three.js" integrity="sha256-QlZjRhqOlDukXFfprbpsdrDQws7TtQdTGDh7F7Q3310=" crossorigin="anonymous"></script>

Cant get Scene to render in Three.js

I'm pretty new to three.js and I can't seem to get my scene (or camera) to render. The other parts are working (I am able to render my adobe illustrator vectors that I converted just fine), however if I comment out my scene, camera & renderer code it makes no difference to what's rendered in the browser.
Here is my html:
<canvas id ="slot">
</canvas>
Here is my js:
var c = document.getElementById('slot');
c.height = 282;
c.width = 400;
var cx = c.getContext('2d');
//This doesn't appear to be working ...
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera( 75, window.innerWidth/window.innerHeight, 0.1, 1000
);
var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
//Working just fine
cx.fillStyle="rgba(255,255,255,0)";
cx.fillRect(0,0,1,1);
cx.fillRect(1,0,1,1);
//....(goes on and on)
var slot = new THREE.Mesh(cx);
// GridHelper
var size = 10;
var divisions = 10;
var gridHelper = new THREE.GridHelper( size, divisions )
// Light
var light = new THREE.AmbientLight(0x404040);
// Fog
var fogColor = 0xFFFFFF;
var near = 10;
var far = 100;
var fog = new THREE.Fog(fogColor, near, far)
scene.add(slot, gridHelper, light, fog)
camera.position.z = 5;
renderer.render( scene, camera );
any help would be greatly appreciated
I have prepared a jsFiddle with your corrected code.
https://jsfiddle.net/EthanHermsey/qampc5b1/49/
var renderer = new THREE.WebGLRenderer({antialias: true});
var cTexture = new THREE.CanvasTexture( c );
var slot = new THREE.Mesh(
new THREE.PlaneGeometry(2, 2),
new THREE.MeshBasicMaterial({
map: cTexture,
transparent: true
})
);
scene.add(slot);
scene.fog = new THREE.Fog(fogColor, near, far);
You cant initialize a Mesh like that.
You have to add the canvas as a CanvasTexture to a material.
You cant .add() fog to the scene, it is like this: scene.fog = new THREE.Fog().
This is what gave the error message.
I don't think you can add multiply objects to the scene like that. (but i'm not sure)
Added antialias to the render (makes edges smoother).

ThreeJS not rendering Cube with setAnimationLoop

So I'm working on a ThreeJS WebVR Page. (I'm quite new to three.js)
So I tired to make a basic scene to test some stuff. But when I load the page with renderer.setAnimationLoop(render) I get my green cube for 1 Frame and then it disappears.
(I got it working with requestAnimationFrame() but this will not work with WebVR)
This is my code for my test sandbox:
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.01, 10);
var renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.vr.enabled = true;
document.body.appendChild(renderer.domElement);
var geometry = new THREE.BoxGeometry(1, 1, 1);
var material = new THREE.MeshBasicMaterial({
color: 0x00ff00
});
var cube = new THREE.Mesh(geometry, material);
scene.add(cube);
camera.position.z = 5;
function render() {
cube.rotation.x += 0.01;
cube.rotation.y += 0.01;
renderer.render(scene, camera);
}
function animate() {
renderer.setAnimationLoop(render);
}
animate();
//Button vor start VR Session
document.body.appendChild(WEBVR.createButton(renderer));
Not the problem with setAnimationLoop
The problem is you cannot set camera position when vr is enabled
check this stack overflow question
Unable to change camera position when using VRControls
Check this CodePen Link where i fixed your code by changing position of cube instead of camera
var cube = new THREE.Mesh(geometry, material);
cube.position.z = -5; //added this instead of camera.position.z = 5;
if you want to move the camera you need make it as child of another object and set the position to that object

Three js in a class

I tried to set all the necessary functionality into one class in order to create a simple three.js scene with a cube. I don't get any errors, but the scene stays black when I open it in the browser.
Here is my code:
class SceneInit {
constructor(fov = 45,camera,scene,controls,renderer)
{
this.camera = camera;
this.scene = scene;
this.controls = controls;
this.renderer = renderer;
this.fov = fov;
}
initScene() {
this.camera = new THREE.PerspectiveCamera(this.fov, window.innerWidth / window.innerHeight, 1, 1000);
this.camera.position.z = 15;
this.controls = new THREE.TrackballControls( this.camera );
//this.controls.addEventListener('change', this.renderScene);
this.scene = new THREE.Scene();
//specify a canvas which is already created in the HTML file and tagged by an id //aliasing enabled
this.renderer = new THREE.WebGLRenderer({canvas: document.getElementById('myThreeJsCanvas') , antialias: true});
this.renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(this.renderer.domElement);
//ambient light which is for the whole scene
let ambientLight = new THREE.AmbientLight(0xffffff, 0.7);
ambientLight.castShadow = false;
this.scene.add(ambientLight);
//spot light which is illuminating the chart directly
let spotLight = new THREE.SpotLight(0xffffff, 0.55);
spotLight.castShadow = true;
spotLight.position.set(0,40,10);
this.scene.add(spotLight);
//if window resizes
window.addEventListener('resize', this.onWindowResize, false);
}
animate(){
requestAnimationFrame( this.animate.bind(this) );
this.render();
this.controls.update();
}
render(){
this.renderer.render( this.scene, this.camera );
}
onWindowResize() {
this.camera.aspect = window.innerWidth / window.innerHeight;
this.camera.updateProjectionMatrix();
this.renderer.setSize( window.innerWidth, window.innerHeight );
}
}
And then I try to instantiate a new object and add an object to the scene. When I try to print the children of the scene, it returns me the right objects, but as I mentioned before the scene stays black. Only the renderer window is getting drawed in the browser.
let test = new SceneInit(45);
test.initScene();
test.animate();
let geometry = new THREE.BoxBufferGeometry( 200, 200, 200 );
let material = new THREE.MeshBasicMaterial();
let mesh = new THREE.Mesh( geometry, material );
test.scene.add(mesh);
console.log(test.scene.children); //returns 3 objects (ambientLight, spotLight, mesh)
I got the answer.
The problem in the code was that the BoxGeometry was too big and the camera was inside the box. With the clipping set to 1 it wouldn't even render it.
So the solution is to set a smaller BoxGeometry. or to move the camera away!

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