Develop Reference

Merging geometries in three.js

I have a scene which contains multiple meshes, each of varying shapes and sizes.
I have looped through each Mesh and using geometry.merge() I have been able to create a new mesh from the geometries in the scene.
I want to mask the entire mesh with an alphaMask, however, each geometry has the material applied to it separately.
An example of this can be seen here - https://codepen.io/danlong/pen/KXOObr
function addObjects(scene) {
// merged geomoetry & material
var mergedGeometry = new THREE.Geometry();
var mergedMaterial = new THREE.MeshStandardMaterial({ color: "#444", transparent: true, side: THREE.DoubleSide, alphaTest: 0.5, opacity: 1, roughness: 1 });
// multiple meshes
var geometry = new THREE.IcosahedronGeometry(30, 5);
var material = new THREE.MeshStandardMaterial({ color: "#444" });
var geo1 = new THREE.IcosahedronGeometry(30, 5);
var mesh1 = new THREE.Mesh( geo1, material );
mesh1.position.x = 10;
mesh1.position.y = 10;
mesh1.position.z = 0;
var geo2 = new THREE.IcosahedronGeometry(30, 5);
var mesh2 = new THREE.Mesh( geo2, material );
mesh2.position.x = 20;
mesh2.position.y = 20;
mesh2.position.z = 0;
var geo3 = new THREE.IcosahedronGeometry(30, 5);
var mesh3 = new THREE.Mesh( geo3, material );
mesh3.position.x = 30;
mesh3.position.y = 30;
mesh3.position.z = 0;
// scene.add(mesh1, mesh2, mesh3);
mesh1.updateMatrix();
mergedGeometry.merge(mesh1.geometry, mesh1.matrix);
mesh2.updateMatrix();
mergedGeometry.merge(mesh2.geometry, mesh2.matrix);
mesh3.updateMatrix();
mergedGeometry.merge(mesh3.geometry, mesh3.matrix);
// alpha texture
var image = document.createElement('img');
var alphaMap = new THREE.Texture(image);
image.onload = function() {
alphaMap.needsUpdate = true;
};
image.src = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAICAYAAADED76LAAAAGUlEQVQoU2NkYGD4z4AHMP7//x+/gmFhAgCXphP14bko/wAAAABJRU5ErkJggg==';
mergedMaterial.alphaMap = alphaMap;
mergedMaterial.alphaMap.magFilter = THREE.NearestFilter;
mergedMaterial.alphaMap.wrapT = THREE.RepeatWrapping;
mergedMaterial.alphaMap.repeat.y = 1;
// merged geometry with alpha mask
merge1 = new THREE.Mesh(mergedGeometry, mergedMaterial);
merge1.rotation.z = -Math.PI/4;
// merge geometry without alpha mask
var merge2 = new THREE.Mesh(mergedGeometry, material);
merge2.position.x = -100;
merge2.rotation.z = -Math.PI/4;
scene.add(merge1, merge2);
return mesh;
}
The mesh on the left is the merged geometries which I want to apply the alphaMask to. The mesh on the right is the outcome of this and instead of the map being applied to the mesh as a whole, each of the geometries has the map applied.
Is there a way to mask the entire mesh and not each geometry?
--
three.js r86
EDIT:
I've tried to apply a clipping plane to my mesh but it's not the effect I'm looking for. I want to be able to apply an alphaMask across the whole mesh and reveal it however I make my mask image. Something like this effect - https://codepen.io/supah/pen/zwJxdb
Is it something to do with the UV's being preserved from the original geometries? Do I need to change these in some way?

I think what you really want is an overlaid mask. This can be accomplished by rendering a single plane that has the alpha map applied, on top of the scene rendering. Using an orthographic camera, and controlling certain renderer settings, such as disabling automatic clearing of color.

Threejs draw a path with textures

I want to draw a path in my 3D world, but the class of line is not useful. Who can help me?!
Like this image
Now I fixed my question
I want draw a path ，and fill it with texture
var SUBDIVISIONS = 20;
geometry = new THREE.Geometry();
var curve = new THREE.QuadraticBezierCurve3();
curve.v0 = new THREE.Vector3(0, 0, 110);
curve.v1 = new THREE.Vector3(0, 200, 110);
curve.v2 = new THREE.Vector3(200, 200, 110);
for (j = 0; j < SUBDIVISIONS; j++) {
geometry.vertices.push( curve.getPoint(j / SUBDIVISIONS) )
}
material = new THREE.LineBasicMaterial( { color: 0xff0000, linewidth: 5 } );
line = new THREE.Line(geometry, material);
scene.add(line);
this way has two problem 1：linewidth is not support on Windows ，2: LineBasicMaterial not support texture
So i search on google find class Three.MeshLine. linewidth is Ok,but texture mapping not fine. texture code there:var loader = new THREE.TextureLoader();
loader.load( 'assets/images.png', function( texture ) {
strokeTexture = texture;
strokeTexture.wrapS = strokeTexture.wrapT = THREE.RepeatWrapping;
strokeTexture.repeat.set( 5, 1);
strokeTexture.needsUpdate = true;
init()
} );
Regardless of the setting the texture and MeshLineMaterial ，The result is not what I want result image：result image

have a look at https://github.com/spite/THREE.MeshLine - it's an implementation of mesh-based lines. Also note the references on that site, could give you some insights.
Otherwise you might want to look into creating a shape from the line. This could be done using the THREE.ShapeGeometry-class.

Incrementally display three.js TubeGeometry

I am able to display a THREE.TubeGeometry figure as follows
Code below, link to jsbin
<html>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r75/three.js"></script>
<script>
// global variables
var renderer;
var scene;
var camera;
var geometry;
var control;
var count = 0;
var animationTracker;
init();
drawSpline();
function init()
{
// create a scene, that will hold all our elements such as objects, cameras and lights.
scene = new THREE.Scene();
// create a camera, which defines where we're looking at.
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
// create a render, sets the background color and the size
renderer = new THREE.WebGLRenderer();
renderer.setClearColor('lightgray', 1.0);
renderer.setSize(window.innerWidth, window.innerHeight);
// position and point the camera to the center of the scene
camera.position.x = 0;
camera.position.y = 40;
camera.position.z = 40;
camera.lookAt(scene.position);
// add the output of the renderer to the html element
document.body.appendChild(renderer.domElement);
}
function drawSpline(numPoints)
{
var numPoints = 100;
// var start = new THREE.Vector3(-5, 0, 20);
var start = new THREE.Vector3(-5, 0, 20);
var middle = new THREE.Vector3(0, 35, 0);
var end = new THREE.Vector3(5, 0, -20);
var curveQuad = new THREE.QuadraticBezierCurve3(start, middle, end);
var tube = new THREE.TubeGeometry(curveQuad, numPoints, 0.5, 20, false);
var mesh = new THREE.Mesh(tube, new THREE.MeshNormalMaterial({
opacity: 0.9,
transparent: true
}));
scene.add(mesh);
renderer.render(scene, camera);
}
</script>
</body>
</html>
However, I would like to display incrementally, as in, like an arc that is loading, such that it starts as the start point, draws incrementally and finally looks the below arc upon completion.
I have been putting in some effort, and was able to do this by storing all the points/coordinates covered by the arc, and drawing lines between the consecutive coordinates, such that I get the 'arc loading incrementally' feel. However, is there a better way to achieve this? This is the link to jsbin
Adding the code here as well
<!DOCTYPE html>
<html>
<head>
<title>Incremental Spline Curve</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r75/three.js"></script>
<style>
body {
margin: 0;
overflow: hidden;
}
</style>
</head>
<script>
// global variables
var renderer;
var scene;
var camera;
var splineGeometry;
var control;
var count = 0;
var animationTracker;
// var sphereCamera;
var sphere;
var light;
function init() {
// create a scene, that will hold all our elements such as objects, cameras and lights.
scene = new THREE.Scene();
// create a camera, which defines where we're looking at.
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
// create a render, sets the background color and the size
renderer = new THREE.WebGLRenderer();
// renderer.setClearColor(0x000000, 1.0);
renderer.setClearColor( 0xffffff, 1 );
renderer.setSize(window.innerWidth, window.innerHeight);
// position and point the camera to the center of the scene
camera.position.x = 0;
camera.position.y = 40;
camera.position.z = 40;
camera.lookAt(scene.position);
// add the output of the renderer to the html element
document.body.appendChild(renderer.domElement);
// //init for sphere
// sphereCamera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000);
// sphereCamera.position.y = -400;
// sphereCamera.position.z = 400;
// sphereCamera.rotation.x = .70;
sphere = new THREE.Mesh(new THREE.SphereGeometry(0.8,31,31), new THREE.MeshLambertMaterial({
color: 'yellow',
}));
light = new THREE.DirectionalLight('white', 1);
// light.position.set(0,-400,400).normalize();
light.position.set(0,10,10).normalize();
//get points covered by Spline
getSplineData();
}
//save points in geometry.vertices
function getSplineData() {
var curve = new THREE.CubicBezierCurve3(
new THREE.Vector3( -5, 0, 10 ),
new THREE.Vector3(0, 20, 0 ),
new THREE.Vector3(0, 20, 0 ),
new THREE.Vector3( 2, 0, -25 )
);
splineGeometry = new THREE.Geometry();
splineGeometry.vertices = curve.getPoints( 50 );
animate();
}
//scheduler loop
function animate() {
if(count == 50)
{
cancelAnimationFrame(animationTracker);
return;
}
//add line to the scene
drawLine();
renderer.render(scene, camera);
// renderer.render(scene, sphereCamera);
count += 1;
// camera.position.z -= 0.25;
// camera.position.y -= 0.25;
animationTracker = requestAnimationFrame(animate);
}
function drawLine() {
var lineGeometry = new THREE.Geometry();
var lineMaterial = new THREE.LineBasicMaterial({
color: 0x0000ff
});
console.log(splineGeometry.vertices[count]);
console.log(splineGeometry.vertices[count+1]);
lineGeometry.vertices.push(
splineGeometry.vertices[count],
splineGeometry.vertices[count+1]
);
var line = new THREE.Line( lineGeometry, lineMaterial );
scene.add( line );
}
// calls the init function when the window is done loading.
window.onload = init;
</script>
<body>
</body>
</html>
Drawback : The drawback of doing it the above way is that, end of the day, I'm drawing a line between consecutive points, and so I lose out on a lot of the effects possible in TubeGeometry such as, thickness, transparency etc.
Please suggest me an alternative way to get a smooth incremental load for the TubeGeometry.

THREE.TubeGeometry returns a THREE.BufferGeometry.
With THREE.BufferGeometry, you have access to a property drawRange that you can set to animate the drawing of the mesh:
let nEnd = 0, nMax, nStep = 90; // 30 faces * 3 vertices/face
...
const geometry = new THREE.TubeGeometry( path, pathSegments, tubeRadius, radiusSegments, closed );
nMax = geometry.attributes.position.count;
...
function animate() {
requestAnimationFrame( animate );
nEnd = ( nEnd + nStep ) % nMax;
mesh.geometry.setDrawRange( 0, nEnd );
renderer.render( scene, camera );
}
EDIT: For another approach, see this SO answer.
three.js r.144

Normally you would be able to use the method .getPointAt() to "get a vector for point at relative position in curve according to arc length" to get a point at a certain percentage of the length of the curve.
So normally if you want to draw 70% of the curve and a full curve is drawn in 100 segments. Then you could do:
var percentage = 70;
var curvePath = new THREE.CurvePath();
var end, start = curveQuad.getPointAt( 0 );
for(var i = 1; i < percentage; i++){
end = curveQuad.getPointAt( percentage / 100 );
lineCurve = new THREE.LineCurve( start, end );
curvePath.add( lineCurve );
start = end;
}
But I think this is not working for your curveQuad since the getPointAt method is not implemented for this type. A work around is to get a 100 points for your curve in an array like this:
points = curve.getPoints(100);
And then you can do almost the same:
var percentage = 70;
var curvePath = new THREE.CurvePath();
var end, start = points[ 0 ];
for(var i = 1; i < percentage; i++){
end = points[ percentage ]
lineCurve = new THREE.LineCurve( start, end );
curvePath.add( lineCurve );
start = end;
}
now your curvePath holds the line segments you want to use for drawing the tube:
// draw the geometry
var radius = 5, radiusSegments = 8, closed = false;
var geometry = new THREE.TubeGeometry(curvePath, percentage, radius, radiusSegments, closed);
Here a fiddle with a demonstration on how to use this dynamically

I'm not really that familiar with three.js. But I think I can be of assistance. I have two solutions for you. Both based on the same principle: build a new TubeGeometry or rebuild the current one, around a new curve.
Solution 1 (Simple):
var CurveSection = THREE.Curve.create(function(base, from, to) {
this.base = base;
this.from = from;
this.to = to;
}, function(t) {
return this.base.getPoint((1 - t) * this.from + t * this.to);
});
You define a new type of curve which just selects a segment out of a given curve. Usage:
var curve = new CurveSection(yourCurve, 0, .76); // Where .76 is your percentage
Now you can build a new tube.
Solution 2 (Mathematics!):
You are using for your arc a quadratic bezier curve, that's awesome! This curve is a parabola. You want just a segment of that parabola and that is again a parabola, just with other bounds.
What we need is a section of the bezier curve. Let's say the curve is defined by A (start), B (direction), C (end). If we want to change the start to a point D and the end to a point F we need the point E that is the direction of the curve in D and F. So the tangents to our parabola in D and F have to intersect in E. So the following code will give us the desired result:
// Calculates the instersection point of Line3 l1 and Line3 l2.
function intersection(l1, l2) {
var A = l1.start;
var P = l2.closestPointToPoint(A);
var Q = l1.closestPointToPoint(P);
var l = P.distanceToSquared(A) / Q.distanceTo(A);
var d = (new THREE.Vector3()).subVectors(Q, A);
return d.multiplyScalar(l / d.length()).add(A);
}
// Calculate the tangentVector of the bezier-curve
function tangentQuadraticBezier(bezier, t) {
var s = bezier.v0,
m = bezier.v1,
e = bezier.v2;
return new THREE.Vector3(
THREE.CurveUtils.tangentQuadraticBezier(t, s.x, m.x, e.x),
THREE.CurveUtils.tangentQuadraticBezier(t, s.y, m.y, e.y),
THREE.CurveUtils.tangentQuadraticBezier(t, s.z, m.z, e.z)
);
}
// Returns a new QuadraticBezierCurve3 with the new bounds.
function sectionInQuadraticBezier(bezier, from, to) {
var s = bezier.v0,
m = bezier.v1,
e = bezier.v2;
var ns = bezier.getPoint(from),
ne = bezier.getPoint(to);
var nm = intersection(
new THREE.Line3(ns, tangentQuadraticBezier(bezier, from).add(ns)),
new THREE.Line3(ne, tangentQuadraticBezier(bezier, to).add(ne))
);
return new THREE.QuadraticBezierCurve3(ns, nm, ne);
}
This is a very mathematical way, but if you should need the special properties of a Bezier curve, this is the way to go.
Note: The first solution is the simplest. I am not familiar with Three.js so I wouldn't know what the most efficient way to implement the animation is. Three.js doesn't seem to use the special properties of a bezier curve so maybe solution 2 isn't that useful.
I hope you have gotten something useful out of this.

copy texture Three.js

I want to load the left half of video texture to left Geometry and right half of video texture to the right Geometry
var video = document.createElement("video");
var texture = new THREE.Texture(video);
texture.offset = new THREE.Vector2(0,0);
texture.repeat = new THREE.Vector2( 0.5, 1 );
var material = new THREE.MeshLambertMaterial({
map: texture,
side: THREE.DoubleSide
});
this is the left plane texture
var texture2 = new THREE.Texture(video);
texture2.minFilter = THREE.NearestFilter;
texture2.offset = new THREE.Vector2(0.5,0);
texture2.repeat = new THREE.Vector2( 0.5, 1 );
var material2 = new THREE.MeshLambertMaterial({
map: texture2,
side: THREE.DoubleSide
});
this is the right plane texture
var plane = new THREE.Mesh(new THREE.PlaneBufferGeometry(320, 240), material);
var plane2 = new THREE.Mesh(new THREE.PlaneBufferGeometry(320, 240), material2);
loading two video texture didn't work,the left plane does display but the right not ,Than I try to copy texture instead of loading the same video texture:
texture2 = THREE.Texture.clone(texture);
or
texture = texture;
both don't work,too.Because(in three.js reference):
.clone(texture)
Make copy of texture. Note this is not a "deep copy", the image is shared.
What if anything can I do ?
function change_uvs( geometry, unitx, unity, offsetx, offsety ) {
var faceVertexUvs = geometry.faceVertexUvs[ 0 ];
for ( var i = 0; i < faceVertexUvs.length; i ++ ) {
var uvs = faceVertexUvs[ i ];
for ( var j = 0; j < uvs.length; j ++ ) {
var uv = uvs[ j ];
uv.x = ( uv.x + offsetx ) * unitx;
uv.y = ( uv.y + offsety ) * unity;
}
}
}
var P1 = new THREE.PlaneGeometry(320, 240);
var p2 = new THREE.PlaneGeometry(320, 240);
change_uvs(p1,0.5,1,0,0);//left plane
change_uvs(p2,0.5,1,1,0);// right plane
by changging the uvMapping of planes i solve the problem :)

If it was to work in theory You will need to change the UV co-ordinates on either plane and add the texture to that. I had a similar issue with an image file more or less, check here :
three.js webgl custom shader sharing texture with new offset
There is a lot of info i had put there and should help you with a resolution.

Draw a circle (not shaded) with Three.js

I am trying to draw a circle very similar to the orbital patterns on this website. I would like to use Three.js instead of pure WebGL.

Three.js r50 added CircleGeometry. It can be seen (albeit with a face) in the WebGL Geometries example.
The first vertex in the geometry is created at the center of the circle (in r84, see CircleGeometry.js line 71, in r65, see CircleGeometry.js line 18), which is nifty if you are going for that "full Pac-Man" or "uninformative pie chart" look. Oh, and it appears to be necessary if you are going to use any material aside from LineBasicMaterial / LineDashedMaterial.
I've verified that the following code works in both r60 & r65:
var radius = 100,
segments = 64,
material = new THREE.LineBasicMaterial( { color: 0x0000ff } ),
geometry = new THREE.CircleGeometry( radius, segments );
// Remove center vertex
geometry.vertices.shift();
// Non closed circle with one open segment:
scene.add( new THREE.Line( geometry, material ) );
// To get a closed circle use LineLoop instead (see also #jackrugile his comment):
scene.add( new THREE.LineLoop( geometry, material ) );
PS: The "docs" now include a nice CircleGeometry interactive example: https://threejs.org/docs/#api/geometries/CircleGeometry

The API changed slightly in newer versions of threejs.
var segmentCount = 32,
radius = 100,
geometry = new THREE.Geometry(),
material = new THREE.LineBasicMaterial({ color: 0xFFFFFF });
for (var i = 0; i <= segmentCount; i++) {
var theta = (i / segmentCount) * Math.PI * 2;
geometry.vertices.push(
new THREE.Vector3(
Math.cos(theta) * radius,
Math.sin(theta) * radius,
0));
}
scene.add(new THREE.Line(geometry, material));
Modify segmentCount to make the circle smoother or more jagged as needed by your scene. 32 segments will be quite smooth for small circles. For orbits such as those on the site you link you, you may want to have a few hundred.
Modify the order of the three components within the Vector3 constructor to choose the orientation of the circle. As given here, the circle will be aligned to the x/y plane.

I used code that Mr.doob references in this github post.
var resolution = 100;
var amplitude = 100;
var size = 360 / resolution;
var geometry = new THREE.Geometry();
var material = new THREE.LineBasicMaterial( { color: 0xFFFFFF, opacity: 1.0} );
for(var i = 0; i <= resolution; i++) {
var segment = ( i * size ) * Math.PI / 180;
geometry.vertices.push( new THREE.Vertex( new THREE.Vector3( Math.cos( segment ) * amplitude, 0, Math.sin( segment ) * amplitude ) ) );
}
var line = new THREE.Line( geometry, material );
scene.add(line);

This example is in the Three.js documentation:
var material = new THREE.MeshBasicMaterial({
color: 0x0000ff
});
var radius = 5;
var segments = 32; //<-- Increase or decrease for more resolution I guess
var circleGeometry = new THREE.CircleGeometry( radius, segments );
var circle = new THREE.Mesh( circleGeometry, material );
scene.add( circle );

I had to do this lol:
function createCircle() {
let circleGeometry = new THREE.CircleGeometry(1.0, 30.0);
circleGeometry.vertices.splice(0, 1); //<= This.
return new THREE.LineLoop(circleGeometry,
new THREE.LineBasicMaterial({ color: 'blue' }));
}
let circle = createCircle();
Reason: Otherwise, it doesn't draw a "pure" circle, there's a line coming from the center to the rim of the circle, even if you use LineLoop instead of Line. Splicing (removing) the first vertex from the array is a hack but seems to do the trick. :)
(Note that apparently, according to mrienstra's answer, "Oh, and it appears to be necessary if you are going to use any material aside from LineBasicMaterial / LineDashedMaterial.")
If you want thickness, though, you're screwed ("Due to limitations of the OpenGL Core Profile with the WebGL renderer on most platforms linewidth will always be 1 regardless of the set value.")... Unless you use: https://github.com/spite/THREE.MeshLine
Code example for that is here: https://stackoverflow.com/a/61312721/1599699

Well, I dunno when they added it - but TorusGeometry should do the job...
THREE TorusGeometry
const geometry = new THREE.TorusGeometry( 10, 3, 16, 100 );
const material = new THREE.MeshBasicMaterial( { color: 0xffff00 } );
const torus = new THREE.Mesh( geometry, material );
scene.add( torus );
Dunno, but I think it shouldn't be (much) more expensive than the line thingy and it's a buffer geometry and you may adjust size and material etc...

See the three.js sample http://mrdoob.github.com/three.js/examples/webgl_lines_colors.html to see how to draw colored lines.
A circle like the ones you cite is drawn as a large # of little straight segments. (Actually, the ones you show may be ellipses)

var getStuffDashCircle2 = function () {
var segment = 100, radius = 100;
var lineGeometry = new THREE.Geometry();
var vertArray = lineGeometry.vertices;
var angle = 2 * Math.PI / segment;
for (var i = 0; i < segment; i++) {
var x = radius * Math.cos(angle * i);
var y = radius * Math.sin(angle * i);
vertArray.push(new THREE.Vector3(x, y, 0));
}
lineGeometry.computeLineDistances();
var lineMaterial = new THREE.LineDashedMaterial({ color: 0x00cc00, dashSize: 4, gapSize: 2 });
var circle = new THREE.Line(lineGeometry, lineMaterial);
circle.rotation.x = Math.PI / 2;
circle.position.y = cylinderParam.trackHeight+20;
return circle;
}

I had some issues getting the other answers to work here -- in particular, CircleGeometry had an extra point at the center of the circle, and I didn't like the hack of trying to remove that vertex.
EllipseCurve does what I wanted (verified in r135):
const curve = new THREE.EllipseCurve(
0.0, 0.0, // Center x, y
10.0, 10.0, // x radius, y radius
0.0, 2.0 * Math.PI, // Start angle, stop angle
);
const pts = curve.getSpacedPoints(256);
const geo = new THREE.BufferGeometry().setFromPoints(pts);
const mat = new THREE.LineBasicMaterial({ color: 0xFF00FF });
const circle = new THREE.LineLoop(geo, mat);
scene.add(circle);