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Threejs apply clipping to specific area of the object

I'm using THREE.Plane to clip my STL model.
localPlane = new THREE.Plane( new THREE.Vector3( 0, -1, 0 ), 4);
.
.
.
material = new THREE.MeshPhongMaterial( {
color: 0xffffff,
side: THREE.DoubleSide,
clippingPlanes: [
localPlane,
],
clipShadows: true
} );
It's working; but the problem is that the whole object's top is clipped by this infinity sized plane. I want it to clip just a small part of it (It seems that there is no way to scale THREE.Plane)
I also tried using ThreeCSG.js but it seems inconvenient with STL objects!
Here is what I get:

Yes, the removal of the intersection of clipping planes is supported in three.js. You can use a pattern like this one:
// clipping planes
var localPlanes = [
new THREE.Plane( new THREE.Vector3( - 1, 0, 0 ), 1 ),
new THREE.Plane( new THREE.Vector3( 0, - 1, 0 ), 1 )
];
// material
var material = new THREE.MeshPhongMaterial( {
color: 0xffffff,
side: THREE.DoubleSide,
clippingPlanes: localPlanes,
clipIntersection: true
} );
Also, see the three.js example.
three.js r.85

Edit: Follow WestLangley's advice. I'll leave this her as an alternate though less efficient means of performing the clipping.
Clipping planes are infinite. There's no getting around that. So what can you do? Multiple clipping planes in multiple render passes!
To do this, you'll need to turn off auto-clearing, and do your own manual buffer clearing.
renderer = new THREE.WebGLRenderer();
renderer.autoClear = false;
Now let's say plane1 is the clipping plane you currently have.
material = new THREE.MeshPhongMaterial( {
...
clippingPlanes: [
plane1,
],
clipShadows: true
} );
var myMesh = new THREE.Mesh(geometry, material);
That clips the top half of myMesh when you call render. So you want to work with the remainder.
First, make another plane, plane2, be the inverse of plane1. plane2 will then clip the BOTTOM of myMesh. But if you render one pass using plane1, and another using plane2, then you're back with a full mesh. So you'll need a third clip plane, plane3, which clips only the desired half of myMesh. Putting plane2 and plane3 in the same render pass will result in only 1/4 of myMesh rendering.
var pass1ClipPlanes = [
plane1
],
pass2ClipLanes = [
plane2, // this plane is the inverse of plane 1, so it clips the opposite of plane1
plane3 // this clips the left/right half of the model
];
Then when you go to render, clear the draw buffers first, then call two render passes, updating the clip planes between them.
// clear the draw buffers
renderer.clear();
// clip the top
myMesh.material.clipPlanes = pass1ClipPlanes;
renderer.render(scene, camera);
// clip the bottom and one side
myMesh.material.clipPlanes = pass2ClipPlanes;
renderer.render(scene, camera);
The first pass renders the bottom of the model, and the second pass renders half of the top.
ETA: Example
var renderer, scene, camera, controls, stats;
var cube,
pass1ClipPlanes,
pass2ClipPlanes;
var WIDTH = window.innerWidth,
HEIGHT = window.innerHeight,
FOV = 35,
NEAR = 1,
FAR = 1000;
function init() {
document.body.style.backgroundColor = "slateGray";
renderer = new THREE.WebGLRenderer({
antialias: true,
alpha: true
});
renderer.localClippingEnabled = true;
renderer.autoClear = false;
document.body.appendChild(renderer.domElement);
document.body.style.overflow = "hidden";
document.body.style.margin = "0";
document.body.style.padding = "0";
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(FOV, WIDTH / HEIGHT, NEAR, FAR);
camera.position.z = 50;
scene.add(camera);
controls = new THREE.TrackballControls(camera, renderer.domElement);
controls.dynamicDampingFactor = 0.5;
controls.rotateSpeed = 3;
var light = new THREE.PointLight(0xffffff, 1, Infinity);
camera.add(light);
stats = new Stats();
stats.domElement.style.position = 'absolute';
stats.domElement.style.top = '0';
document.body.appendChild(stats.domElement);
resize();
window.onresize = resize;
// POPULATE EXAMPLE
var plane1 = new THREE.Plane(new THREE.Vector3(0, -1, 0), 0),
plane2 = new THREE.Plane(new THREE.Vector3(0, 1, 0), 0),
plane3 = new THREE.Plane(new THREE.Vector3(-1, 0, 0), 0);
pass1ClipPlanes = [plane1];
pass2ClipPlanes = [plane2, plane3];
var cubeGeo = new THREE.BoxBufferGeometry(10, 10, 10),
cubeMat = new THREE.MeshPhongMaterial({
color: "red",
side: THREE.DoubleSide
});
cube = new THREE.Mesh(cubeGeo, cubeMat);
scene.add(cube);
animate();
}
function resize() {
WIDTH = window.innerWidth;
HEIGHT = window.innerHeight;
if (renderer && camera && controls) {
renderer.setSize(WIDTH, HEIGHT);
camera.aspect = WIDTH / HEIGHT;
camera.updateProjectionMatrix();
controls.handleResize();
}
}
function render() {
renderer.clear();
cube.material.clippingPlanes = pass1ClipPlanes;
renderer.render(scene, camera);
cube.material.clippingPlanes = pass2ClipPlanes;
renderer.render(scene, camera);
}
function animate() {
requestAnimationFrame(animate);
render();
controls.update();
stats.update();
}
function threeReady() {
init();
}
(function() {
function addScript(url, callback) {
callback = callback || function() {};
var script = document.createElement("script");
script.addEventListener("load", callback);
script.setAttribute("src", url);
document.head.appendChild(script);
}
addScript("https://threejs.org/build/three.js", function() {
addScript("https://threejs.org/examples/js/controls/TrackballControls.js", function() {
addScript("https://threejs.org/examples/js/libs/stats.min.js", function() {
threeReady();
})
})
})
})();

Why can't I have a shadow by pointlight in three.js?

I want to have shadows, I set as follows, really wondering what's the problem? I have a grid, with cubic and sphere as a child of it, and also I set the castShadow and Receive shadow for them but it has no result for shadow.
some parts of my code:
var camera, scene, renderer, dice, dice1;
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(35,window.innerWidth/window.innerHeight, 0.1, 1000);
// Z is up for objects intended to be 3D printed.
camera.up.set(0, 0, 1);
scene.add(camera);
renderer = new THREE.WebGLRenderer({antialias: true});
renderer.setClearColor(0x999999);
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
document.body.appendChild(renderer.domElement);
var light = new THREE.PointLight(0x000000, 1, 1000);
light.position.set(10, 10,10);
light.castShadow = true; // default false
scene.add(light);
//Set up shadow properties for the light;
light.shadow.mapSize.width = 1024; // default
light.shadow.mapSize.height = 1024; // default
light.shadow.camera.near = 1; // default
light.shadow.camera.far = 1000 // default
var grid = new THREE.GridHelper(50, 50, 0xffffff, 0x555555);
grid.colorGrid = 0x00ff00;
grid.rotateOnAxis(new THREE.Vector3(1, 0, 0), 90 * (Math.PI / 180));
scene.add(grid);
objects.push(grid); // add to the array for DragControls
grid.receiveShadow=true;
//Create a sphere that cast shadows (but does not receive them)
var sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
sphere.castShadow = true; //default is false
sphere.receiveShadow = false; //default
sphere.position.set(10, 15, 10);
scene.add(sphere);
//initializing the color cubic
var material = new THREE.MeshBasicMaterial({
color: 0xff0000});
dice = new THREE.Mesh(new THREE.BoxGeometry(5, 5, 5, 1, 1, 1), material);
dice.position.set(10, 2.5, 10);
dice.castShadow = true;
grid.add(dice);

You cannot cast shadow on a grid. it is just lines.
Add this in your code to see shadows.
var plane = new THREE.Mesh(new THREE.PlaneGeometry(50,50), new THREE.MeshStandardMaterial( {color: 0x00ff00 }));
plane.castShadow = false;
plane.receiveShadow = true;
plane.position.set(0, 0, -1);
scene.add(plane);

Light rays from point light three.js

Is there a way to see the light rays from a point light in a Three js scene. I have tried fog but it makes the whole objects in the scene the color of fog.
var width = $('#g_pre_emo').width();
var scene = new THREE.Scene();
scene.fog = new THREE.Fog(0xffff00, 0, 10);
var camera = new THREE.PerspectiveCamera(50, width / 500, 0.1, 1000);
var renderer = new THREE.WebGLRenderer({antialias: false});
renderer.setSize(width, 500);
$('#g_pre_emo').append(renderer.domElement);
var intensity = 2.5;
var distance = 5;
var decay = 2.0;
var light = new THREE.AmbientLight(0x404040); // soft white light
scene.add(light);
renderer.shadowMap.Enabled = true;
renderer.setClearColor(0xffffff, 1);
var happyGroup = new THREE.Object3D();
var sadGroup = new THREE.Object3D();
var angryGroup = new THREE.Object3D();
var relaxedGroup = new THREE.Object3D();
scene.add(happyGroup);
scene.add(sadGroup);
scene.add(angryGroup);
scene.add(relaxedGroup);
var c1 = 0xffff00;
var sphere = new THREE.SphereGeometry(0.25, 16, 8);
light1 = new THREE.PointLight(c1, intensity, distance, decay);
light1.add(new THREE.Mesh(sphere, new THREE.MeshBasicMaterial({color: c1})));
scene.add(light1);
happyGroup.position.set(-3, 3, 0);
sadGroup.position.set(3, 3, 0);
angryGroup.position.set(-3, -3, 0);
relaxedGroup.position.set(3, -3, 0);
var happyGeometry = new THREE.SphereGeometry(1, 50, 50);
var happyMaterial = new THREE.MeshNormalMaterial();
var happySphere = new THREE.Mesh(happyGeometry, happyMaterial);
scene.add(happySphere);
happyGroup.add(happySphere);
var sadGeometry = new THREE.SphereGeometry(1, 50, 50);
var sadMaterial = new THREE.MeshNormalMaterial();
var sadSphere = new THREE.Mesh(sadGeometry, sadMaterial);
scene.add(sadSphere);
sadGroup.add(sadSphere);
var angryGeometry = new THREE.SphereGeometry(1, 50, 50);
var angryMaterial = new THREE.MeshNormalMaterial();
var angrySphere = new THREE.Mesh(angryGeometry, angryMaterial);
scene.add(angrySphere);
angryGroup.add(angrySphere);
var relaxedGeometry = new THREE.SphereGeometry(1, 50, 50);
var relaxedMaterial = new THREE.MeshNormalMaterial();
var relaxedSphere = new THREE.Mesh(relaxedGeometry, relaxedMaterial);
scene.add(relaxedSphere);
relaxedGroup.add(relaxedSphere);
renderer.gammaInput = true;
renderer.gammaOutput = true;
camera.position.z = 15;
function render() {
renderer.render(scene, camera);
}
;
render();
animate();
function animate() {
requestAnimationFrame(animate);
}
If i run the above code the i cant see any fog in the scene
the fiddle for above code is
https://jsfiddle.net/bqv5ynbo/1/

Possibly, you can use VolumetricSpotlightMaterial from Jerome Etienne.
For me it worked well for Three.js r71, though I haven't tried it with later revisions.
Example of usage

'Light Rays' aren't an automatically occurring thing.
Typically, light rays are created using advanced pixel shaders (stencil/shadow projection over lit region / volumetric fog) or in simple cases by creating simple alpha-blended polygons with 'ray' textures applied.
A point light is simply a light that does not apply directional calculations during it's shading phase. Instead, only distance based calculations are made.
Good Luck!

How to get a shadow using SpriteMaterial and a DirectionalLight

My code :
Directional light :
light = new THREE.DirectionalLight(0xffffff, 1);
light.position.set(-50, 50, 300);
light.castShadow = true;
light.shadowDarkness = 0.4;
light.shadowMapWidth = 1024;
light.shadowMapHeight = 1024;
scene.add(light);
Sprite :
var spriteMaterial = new THREE.SpriteMaterial({map: texture});
var info = new THREE.Sprite( spriteMaterial );
info.castShadow = true;
info.scale.set(infoScale, infoScale, infoScale);
info.name = continent.label;
info.userData.continent = continent;
info.userData.id = continent.id;
info.userData.type = 'info';
hubInfos.push(info);
Here is the result my aircraft has a shadow but not the sprite

Sprites in three.js do not cast shadows.
One work-around is to use PlaneGeometry like so:
scene.add( plane );
plane.lookAt( camera );
Note: LookAt() will not work correctly if the plane is a child of a rotating object; it must be a child of the scene.
three.js r.74

three.js directional light shadows

http://jsfiddle.net/wp6E3/3/
var camera, scene, renderer;
var cubes = [];
init();
animate();
function init() {
scene = new THREE.Scene();
scene.add(new THREE.AmbientLight(0x212223));
for (var i = 0; i < 10; i++) {
var cubeGeometry = new THREE.CubeGeometry(1, 1.5, 1);
var cubeMaterial = new THREE.MeshLambertMaterial({ color: 0x1ec876 });
var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
cube.position.set(i*1.2, 0, 0.5);
cube.castShadow = true;
scene.add(cube);
cubes.push(cube);
}
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 10000);
camera.position.x = -4;
camera.position.y = -4;
camera.position.z = 20;
camera.lookAt(cubes[5].position);
scene.add(camera);
var terrainGeo = new THREE.PlaneGeometry(50, 50);
var terrainMaterial = new THREE.MeshLambertMaterial({ color: 0xc0c0a0 });
var terrain = new THREE.Mesh(terrainGeo, terrainMaterial);
terrain.receiveShadow = true;
scene.add(terrain);
var light = new THREE.DirectionalLight(0xffffff, 1);
light.castShadow = true;
light.shadowCameraVisible = true;
light.position.set(-3, 1, 5);
scene.add(light);
scene.add( new THREE.DirectionalLightHelper(light, 0.2) );
renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.shadowMapEnabled = true;
renderer.shadowMapSoft = false;
document.body.appendChild(renderer.domElement);
}
function animate() {
requestAnimationFrame(animate);
for (var i = 0; i < cubes.length; i++) {
cubes[i].rotation.x += 0.01 * i;
cubes[i].rotation.y += 0.02 * i;
}
renderer.render(scene, camera);
}
Why shadows doesn't work?
I've looked related questions and three.js references but don't understand what I do wrong.
Three.js shadows not working properly
How to create directional light shadow in Three.JS?
ThreeJS shadow not rendering
http://threejs.org/docs/#Reference/Lights/DirectionalLight
http://learningthreejs.com/blog/2012/01/20/casting-shadows/

First of all, add a camera controller to your scene so you can see what you are doing. Now you can rotate the camera for different views.
controls = new THREE.OrbitControls( camera, renderer.domElement );
Second, when using a jsfiddle, be sure to link to the recent version of the three.js library.
<script src="http://threejs.org/build/three.min.js"></script>
For proper resolution, is important that your shadow camera is positioned tight around your scene. You do that by setting the following:
light.shadowCameraLeft = -20; // or whatever value works for the scale of your scene
light.shadowCameraRight = 20;
light.shadowCameraTop = 20;
light.shadowCameraBottom = -20;
For directional lights, only the "direction to" the light's position matters. However, when shadow maps are involved, the actual position of the light is important, since it controls the shadow camera, too.
light.position.set( -60, 20, 100 );
Here is an updated fiddle. Rotate the camera with the mouse.
http://jsfiddle.net/wp6E3/4/
three.js r.66

Add these to your light definition:
light.shadowMapWidth =
light.shadowMapHeight = 1024;
light.shadowCameraNear = 1;
light.shadowCameraFar = 100;