Why doesn't my directional light affect the whole scene? - three.js

Please see this fiddle - http://jsfiddle.net/vnr2v6mL/
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);
var geometry = new THREE.BoxGeometry(100, 100, 1);
var material = new THREE.MeshPhongMaterial({ color: 0x00ff00 });
var plane = new THREE.Mesh(geometry, material);
scene.add(plane);
camera.position.z = 5;
//scene.add(new THREE.AmbientLight(0xdddddd));
var dl = new THREE.DirectionalLight(0x0000ff, 1.0);
dl.position.set(0, 0, 10);
scene.add(dl);
scene.add( new THREE.DirectionalLightHelper(dl, 2.5) );
function render() {
requestAnimationFrame( render );
renderer.render( scene, camera );
}
render();
$(document).ready(function() {
$(document).bind("mousewheel DOMMouseScroll", function(e) {
var delta = e.type === 'DOMMouseScroll' ? -e.originalEvent.detail : e.originalEvent.wheelDelta;
camera.position.z += delta / 120;
});
});
It is my understanding that the lighting should be infinite and parallel, so why does it only light up a circle in the middle of my scene?
Thanks in advance.

You are using MeshPhongMaterial. What you are seeing is the specular highlight only.
Your light is blue. However, your material is green, so it reflects only green light. Therefore, there is no diffuse light reflected from the material.
The material specular reflectance is, by default, 0x111111. So all colors are reflected specularly. Since your light is blue, you get a blue light reflected specularly. In other words, a blue "hot spot".
Consider using a white light, 0xffffff, and adjust the light intensity.
Fiddle: http://jsfiddle.net/vnr2v6mL/1/
three.js r.70

Related

ThreeJS - Create cube where the surfaces are transparent instead of the cube volume

I am using the following code to create this 3D transparent cube.
// Create the cube itself
const cubeGeom = new THREE.BoxGeometry( 1, 1, 1 );
const material = new THREE.MeshBasicMaterial( {color: 0x00ff00, opacity:0.4, transparent:true});
const cube = new THREE.Mesh( cubeGeom, material );
// Also add a wireframe to the cube to better see the depth
const _wireframe = new THREE.EdgesGeometry( cubeGeom ); // or WireframeGeometry( geometry )
const wireframe = new THREE.LineSegments( _wireframe);
// Rotate it a little for a better vantage point
cube.rotation.set(0.2, -0.2, -0.1)
wireframe.rotation.set(0.2, -0.2, -0.1)
// add to scene
scene.add( cube )
scene.add( wireframe );
As can been seen, the cube appears as a single volume that is transparent. Instead, I would want to create a hollow cube with 6 transparent faces. Think of a cube made out of 6 transparent and colored window-panes. See this example: my desired result would be example 1 for each of the 6 faces, but now it is like example 2.
Update
I tried to create individual 'window panes'. However the behavior is not as I would expect.
I create individual panes like so:
geometry = new THREE.PlaneGeometry( 1, 1 );
material = new THREE.MeshBasicMaterial( {color: 0x00ff00, side: THREE.DoubleSide, transparent:true, opacity:0.2});
planeX = new THREE.Mesh( geometry, material);
planeY = new THREE.Mesh( geometry, material);
planeZ = new THREE.Mesh( geometry, material);
And then I add all three planes to wireframe.
Then I rotate them a little, so they intersect at different orientations.
const RAD_TO_DEG = Math.PI * 2 / 360;
planeX.rotation.y = RAD_TO_DEG * 90
planeY.rotation.x = RAD_TO_DEG * 90
Now I can see the effect of 'stacking' the panes on top of each other, however it is not as it should be.
I would instead expect something like this based on real physics (made with terrible paint-skills). That is, the color depends on the number of overlapping panes.
EDIT
When transparent panes overlap from the viewing direciton, transparancy appears to work perfectly. However, when the panes intersect it breaks.
Here I have copied the snipped provided by #Anye and added one.rotation.y = Math.PI * 0.5 and commented out two.position.set(0.5, 0.5, 0.5); so that the panes intersect.
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 );
var cube = new THREE.Group();
one = new Pane();
two = new Pane();
one.rotation.y = Math.PI * 0.5
one.position.z = 0.2;
// two.position.set(0.5, 0.5, 0.5);
cube.add(one);
cube.add(two);
cube.rotation.set(Math.PI / 4, Math.PI / 4, Math.PI / 4);
scene.add(cube);
function Pane() {
let geometry = new THREE.PlaneGeometry(1, 1);
let material = new THREE.MeshBasicMaterial({color:0x00ff00, transparent: true, opacity: 0.4});
let mesh = new THREE.Mesh(geometry, material);
return mesh;
}
camera.position.z = 2;
var animate = function () {
requestAnimationFrame( animate );
renderer.render(scene, camera);
};
animate();
body {
margin: 0;
overflow: hidden;
}
canvas {
width: 640px;
height: 360px;
}
<html>
<head>
<title>Demo</title>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/87/three.min.js"></script>
</body>
</html>
EDIT
The snipped looks pretty good; it clearly shows a different color where the panes overlap. However, it does not show this everywhere. See this image. The left is what the snippet generates, the right is what it should look like. Only the portion of overlap that is in front of the intersection shows the discoloration, while the section behind the intersection should, but does not show discoloration.
You might want to take a look at CSG, Constructive Solid Geometry. With CSG, you can create a hole in your original cube using a boolean. To start, you could take a look at this quick tutorial. Below are some examples of what you can do with CSG.
var cube = new CSG.cube();
var sphere = CSG.sphere({radius: 1.3, stacks: 16});
var geometry = cube.subtract(sphere);
=>
CSG, though, has some limitations, since it isn't made specifically for three.js. A cheap alternative would be to create six individual translucent panes, and format them to create a cube. Then you could group them:
var group = new THREE.Group();
group.add(pane1);
group.add(pane2);
group.add(pane3);
group.add(pane4);
group.add(pane5);
group.add(pane6);
Update
Something may be wrong with your code, which is why it isn't shading accordingly for you. See this minimal example, which shows how the panes shade appropriately based on overlaps.
Update 2
I updated the snippet so the 2 panes aren't touching at all... I am still able to see the shading. Maybe if you were to try to reproduce this example?
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 );
var cube = new THREE.Group();
one = new Pane();
two = new Pane();
one.rotation.y = Math.PI * 0.5;
one.position.z = 0.2;
cube.add(one);
cube.add(two);
cube.rotation.set(Math.PI / 4, Math.PI / 4, Math.PI / 4);
scene.add(cube);
function Pane() {
let geometry = new THREE.PlaneGeometry(1, 1);
let material = new THREE.MeshBasicMaterial({color:0x00ff00, transparent: true, opacity: 0.4});
material.depthWrite = false
let mesh = new THREE.Mesh(geometry, material);
return mesh;
}
camera.position.z = 2;
var animate = function () {
requestAnimationFrame( animate );
renderer.render(scene, camera);
};
animate();
body {
margin: 0;
overflow: hidden;
}
canvas {
width: 640px;
height: 360px;
}
<html>
<head>
<title>Demo</title>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/87/three.min.js"></script>
</body>
</html>
Update 3
Below is a screenshot of what I see in your snippet... Seems to be working fine...
You're experiencing one of my first head-scratchers:
ShaderMaterial transparency
As the answer to that question states, the three.js transparency system performs order-dependent transparency. Normally, it will take whichever object is closest to the camera (by mesh position), but because all of your planes are centered at the same point, there is no winner, so you get some strange transparency effects.
If you move the plane meshes out to form the actual sides of the box, then you should see the effect you're looking for. But that won't be the end of strange transparency effects, And you would need to implement your own Order-Independent Transparency (or find an extension library that does it for you) to achieve more physically-accurate transparency effects.

THREE DirectionalLight falling off with distance

According to the docs for THREE.DirectionalLight:
This light will behave as though it is infinitely far away and the rays produced from it are all parallel.
But, I'm finding that as a move an object with THREE.MeshStandardMaterial farther away from the light (but kept at the same relative angle), the intensity of the light decreases. This doesn't seem right to me.
var canvas = document.createElement("canvas");
document.body.appendChild(canvas);
var dpr = window.devicePixelRatio;
var renderer = new THREE.WebGLRenderer({canvas: canvas, antialias: true});
renderer.setPixelRatio(dpr);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0);
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 0.1, 1000);
camera.position.z = 700;
var planeGeom = new THREE.PlaneGeometry(200, 200);
var plane = new THREE.Mesh(planeGeom, new THREE.MeshStandardMaterial({color: 0xff00ff, metalness: 1}));
plane.position.z = -10;
scene.add(plane);
var light = new THREE.DirectionalLight(0xffffff, 1);
light.position.set(-50, 50, 100);
scene.add(light);
var helper = new THREE.DirectionalLightHelper(light, 10);
scene.add(helper);
function update(time) {
plane.position.x = 200 * Math.sin(time);
plane.position.y = 200 * Math.cos(time/2);
}
function render() {
requestAnimationFrame(render);
update(performance.now() / 1000);
renderer.render(scene, camera);
}
render();
body {
margin: 0;
padding: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/86/three.min.js"></script>
I expect the plane to be lit the same no matter what position it's in. What am I doing wrong?
You are using MeshStandardMaterial and have set metalness to 1.
Metals reflect primarily specularly; the diffuse component of the reflection is minimal.
So what you are seeing is the "hot spot" of the reflection. Set the metalness to zero, for example, and you will see primarily a diffuse reflection.
Also, when using MeshStandardMaterial, you should include an environment map (material.envMap) so there is something to reflect. Materials -- especially metals -- will look much better that way.
three.js r.87

How do I manipulate shadows in Three.js without editing the underlying mesh?

I'm working on an app that should allow users to manipulate 3D objects in the scene and observe how their changes affect the ground shadow:
In this scene, the yellow cylinder casts a shadow on a white plane with the middle of the cylinder contained in the green cube. What I would like to happen is for the cube to remove the middle of the shadow, like so:
Obviosly, my first thought was to subtract the green cube volume from the yellow cylinder volume and after a bit of googling I found CSG.js. Unfortunately, CSG.js is too slow for the actual model that I'm going to use, which will going to have at least 15k vertices.
I started digging into the Three.js source and reading about shadow maps to understand how shadows are produced, but my shader-fu is not strong enough yet to fully grasp how I can tweak shadow rendering.
How can I achieve this "shadow subtraction" effect?
var camera, scene, renderer;
init();
animate();
function init() {
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 1, 1000 );
camera.position.z = 500;
camera.position.y = 100;
camera.lookAt(scene.position);
var ambient = new THREE.AmbientLight(0x909090);
scene.add(ambient);
var directionalLight = new THREE.DirectionalLight( 0xffffff, 1.0 );
directionalLight.position.set( -300, 300, 0 );
directionalLight.castShadow = true;
directionalLight.shadow.camera.near = 10;
directionalLight.shadow.camera.far = 2000;
directionalLight.shadow.camera.right = 350;
directionalLight.shadow.camera.left = -350;
directionalLight.shadow.camera.top = 350;
directionalLight.shadow.camera.bottom = -350;
directionalLight.shadow.mapSize.width = 1024;
directionalLight.shadow.mapSize.height = 1024;
scene.add( directionalLight );
//var lightHelper = new THREE.CameraHelper(directionalLight.shadow.camera);
//scene.add(lightHelper);
var geometry = new THREE.CylinderGeometry( 50, 50, 400, 32 );
var material = new THREE.MeshPhongMaterial( {color: 0xffff00} );
var cylinder = new THREE.Mesh( geometry, material );
cylinder.castShadow = true;
scene.add( cylinder );
var geometry = new THREE.BoxGeometry( 110, 110, 110 );
var material = new THREE.MeshPhongMaterial( {color: 0x00ff00} );
var cube = new THREE.Mesh( geometry, material );
cube.castShadow = true;
scene.add( cube );
var geometry = new THREE.PlaneGeometry( 3000, 3000, 32 );
var material = new THREE.MeshPhongMaterial( {color: 0xffffff, side: THREE.DoubleSide} );
var plane = new THREE.Mesh( geometry, material );
plane.lookAt(new THREE.Vector3(0, 1, 0));
plane.position.y = -200;
plane.receiveShadow = true;
scene.add( plane );
renderer = new THREE.WebGLRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.BasicShadowMap;
document.body.appendChild( renderer.domElement );
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
function animate() {
requestAnimationFrame( animate );
renderer.render( scene, camera );
}
jsFiddle
Update:
What about a more complicated scene? Is it possible for the shadow from the red cylinder to be unaffected (you can see it being cut in half with cube.customDepthMaterial = new THREE.MeshBasicMaterial({ depthTest: false}))?
Updated jsFiddle
You can subtract an object's shadow from the rest of scene by setting the object's .customDepthMaterial property like so:
var cube = new THREE.Mesh( geometry, material );
cube.castShadow = true;
cube.receiveShadow = false;
// The secret sauce
cube.customDepthMaterial =
new THREE.MeshBasicMaterial({ depthTest: false});
scene.add( cube );
jsFiddle
No shader-fu required.
Why This Works
When the shadow map is rendered, each object's depth material ( .customDepthMaterial or the default ) is used to render the scene from the light's perspective. The depth material's resulting render represents the object's depth from the camera packed as RGBA. Since THREE.MeshBasicMaterial defaults to { color: 0xffffff, opacity: 1 }, it will return the maximum depth which makes the object further than the shadow camera's far.
I disabled depthTest because in your desired result screenshot you clipped the area where the cube's given the cylinder wasn't there. Disabling depthTest means that parts of the cube which are blocked by the cylinder will still cut out the shadow, giving you your desired result.
Documentation
There unfortunately is no documentation on .customDepthMaterial yet but I did find an official example where it is used.
Updated Answer:
To allow an object's shadow to always show:
You can use the same trick as above just setting the material's color and opacity to 0
Make sure it's added to the scene after the 'subtractive shadow' object. This way the additive shadow will win out even though they both have depthTest disabled.
updated jsFiddle
If you have anything more complicated, it will be up to you to figure out a way to manage the order of the shadow rendering.
Tested in r77

Texture in three.js no console errors still not working

I'm new to three.js and need to make a project for school. For this project I need a texture on my cube. But the screen stays black.. and there are no console errors! I did everything I can so this is kinda my last change haha.
My code:
<script src="js/three.min.js"></script>
<script>
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 );
var geometry = new THREE.BoxGeometry( 1, 1, 1 );
// +
var material = new THREE.MeshLambertMaterial({
map: THREE.ImageUtils.loadTexture('images/crate2.jpg')
})
// =
var cube = new THREE.Mesh( geometry, material );
scene.add( cube );
camera.position.z = 5;
var render = function () {
requestAnimationFrame( render );
cube.rotation.x += 0.1;
cube.rotation.y += 0.05;
renderer.render(scene, camera);
};
render();
</script>
You do not have a light in your scene.
Adding one like below should work
// Create ambient light and add to scene.
var light = new THREE.AmbientLight(0xffffff); // white light
scene.add(light);
I would add a link to a js fiddle but it seems they have changed and I can not longer find where to get the link.
Anyway, just ad some sort of light.
Perhaps adding a light would help? That or try using THREE.MeshBasicMaterial

Identifying overlap region of two geometries in a canvas using THREE.js

I need to identify the overlapping region of two geometries in a canvas and show the overlapping region with different color/texture.
sample code: http://jsfiddle.net/v4B3d/1/
var camera, scene, renderer, geometry, material, mesh,mesh2;
init();
animate();
function init() {
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 1, 10000);
camera.position.z = 500;
scene.add(camera);
geometry = new THREE.CubeGeometry(100, 100, 100);
material = new THREE.MeshNormalMaterial();
mesh = new THREE.Mesh(geometry, material);
mesh2 = new THREE.Mesh(geometry, material);
scene.add(mesh);
scene.add(mesh2);
mesh.position.y = -30;
mesh2.position.y = 40;
renderer = new THREE.CanvasRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
}
function animate() {
requestAnimationFrame(animate);
render();
}
function render() {
mesh.rotation.x += 0.01;
mesh.rotation.y += 0.02;
mesh2.rotation.x += 0.01;
mesh2.rotation.y += 0.02;
renderer.render(scene, camera);
}
Please let me know how to achieve this.
Thanks in advance.
You probably want to make a third geometry from the overlapping region. You can then render that however you want.
This can be achieved using Constructive Solid Geometry (CSG) boolean operations (namely, intersection). If you only want to render the overlapping part, you can render only the intersection result.
There is a Three.js wrapper for CSG.js library, that should make it easy. See http://learningthreejs.com/blog/2011/12/10/constructive-solid-geometry-with-csg-js/ , http://www.chandlerprall.com/2011/12/constructive-solid-geometry-with-three-js/ and http://en.wikipedia.org/wiki/Constructive_solid_geometry for more information.

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