Related
I'am trying to change position/translate dinamicaly of TubeBufferGeometry.parameters.path which i will use for camera animation
(all are based on this example: webgl_geometry_extrude_splines)
here is my peace of code so far
full code: Link to codesandbox with full code
Important part of code:
function init(){
// initial scene render etc. for full code take a look at codesanbox
// tube
var extrudePath = new Curves.GrannyKnot();
tubeGeometry = new THREE.TubeBufferGeometry( extrudePath, 50, 2, 1, true );
tubeGeometry.dynamic = true;
//unsuccessful approach to change the parameters of position
tubeGeometry.translate(100, 0, 0)
tubeGeometry.attributes.position.needsUpdate = true;
}
function animate() {
requestAnimationFrame( animate );
render();
}
function render() {
// animate camera along spline
var time = Date.now();
var looptime = 20 * 1000;
var t = ( time % looptime ) / looptime;
var pos = tubeGeometry.parameters.path.getPointAt( t );
pos.multiplyScalar( 1 );
splineCamera.position.copy( pos );
renderer.render( scene, splineCamera );
}
The resault is giving me no translation of camera its moving around GrannyKnot curve in default position.
What i'm expecting is to dynamic change position/translate of TubeBufferGeometry.parameters.path in some direction (for example position X + 100) which affects on my camera movement
EDIT
I just realised that i could change camera by adding
function render() {
// animate camera along spline
var time = Date.now();
var looptime = 20 * 1000;
var t = ( time % looptime ) / looptime;
var pos = tubeGeometry.parameters.path.getPointAt( t );
pos.x += 100; //<----this line added
pos.multiplyScalar( 1 );
splineCamera.position.copy( pos );
renderer.render( scene, splineCamera );
}
But if someone would show me how to change TubeBufferGeometry.parameters.path without changing definite pos.x like in code above it. I would be very glad for that.
I am currently trying to create some smooth terrain using the PlaneBufferGeometry of three.js from a height map I got from Google Images:
https://forums.unrealengine.com/filedata/fetch?id=1192062&d=1471726925
but the result is kinda choppy..
(Sorry, this is my first question and evidently I need 10 reputation to post images, otherwise I would.. but here's an even better thing: a live demo! left click + drag to rotate, scroll to zoom)
I want, like i said, a smooth terrain, so am I doing something wrong or is this just the result and i need to smoothen it afterwards somehow?
Also here is my code:
const IMAGE_SRC = 'terrain2.png';
const SIZE_AMPLIFIER = 5;
const HEIGHT_AMPLIFIER = 10;
var WIDTH;
var HEIGHT;
var container = jQuery('#wrapper');
var scene, camera, renderer, controls;
var data, plane;
image();
// init();
function image() {
var image = new Image();
image.src = IMAGE_SRC;
image.onload = function() {
WIDTH = image.width;
HEIGHT = image.height;
var canvas = document.createElement('canvas');
canvas.width = WIDTH;
canvas.height = HEIGHT;
var context = canvas.getContext('2d');
console.log('image loaded');
context.drawImage(image, 0, 0);
data = context.getImageData(0, 0, WIDTH, HEIGHT).data;
console.log(data);
init();
}
}
function init() {
// initialize camera
camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, .1, 100000);
camera.position.set(0, 1000, 0);
// initialize scene
scene = new THREE.Scene();
// initialize directional light (sun)
var sun = new THREE.DirectionalLight(0xFFFFFF, 1.0);
sun.position.set(300, 400, 300);
sun.distance = 1000;
scene.add(sun);
var frame = new THREE.SpotLightHelper(sun);
scene.add(frame);
// initialize renderer
renderer = new THREE.WebGLRenderer();
renderer.setClearColor(0x000000);
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
container.append(renderer.domElement);
// initialize controls
controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.dampingFactor = .05;
controls.rotateSpeed = .1;
// initialize plane
plane = new THREE.PlaneBufferGeometry(WIDTH * SIZE_AMPLIFIER, HEIGHT * SIZE_AMPLIFIER, WIDTH - 1, HEIGHT - 1);
plane.castShadow = true;
plane.receiveShadow = true;
var vertices = plane.attributes.position.array;
// apply height map to vertices of plane
for(i=0, j=2; i < data.length; i += 4, j += 3) {
vertices[j] = data[i] * HEIGHT_AMPLIFIER;
}
var material = new THREE.MeshPhongMaterial({color: 0xFFFFFF, side: THREE.DoubleSide, shading: THREE.FlatShading});
var mesh = new THREE.Mesh(plane, material);
mesh.rotation.x = - Math.PI / 2;
mesh.matrixAutoUpdate = false;
mesh.updateMatrix();
plane.computeFaceNormals();
plane.computeVertexNormals();
scene.add(mesh);
animate();
}
function animate() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
controls.update();
}
The result is jagged because the height map has low color depth. I took the liberty of coloring a portion of the height map (Paint bucket in Photoshop, 0 tolerance, non-continuous) so you can see for yourself how large are the areas which have the same color value, i.e. the same height.
The areas of the same color will create a plateau in your terrain. That's why you have plateaus and sharp steps in your terrain.
What you can do is either smooth out the Z values of the geometry or use a height map which utilizes 16bits or event 32bits for height information. The current height map only uses 8bits, i.e. 256 values.
One thing you could do to smooth things out a bit is to sample more than just a single pixel from the heightmap. Right now, the vertex indices directly correspond to the pixel position in the data-array. And you just update the z-value from the image.
for(i=0, j=2; i < data.length; i += 4, j += 3) {
vertices[j] = data[i] * HEIGHT_AMPLIFIER;
}
Instead you could do things like this:
get multiple samples with certain offsets along the x/y axes
compute an (weighted) average value from the samples
That way you would get some smoothing at the borders of the same-height areas.
The second option is to use something like a blur-kernel (gaussian blur is horribly expensive, but maybe something like a fast box-blur would work for you).
As you are very limited in resolution due to just using a single byte, you should convert that image to float32 first:
const highResData = new Float32Array(data.length / 4);
for (let i = 0; i < highResData.length; i++) {
highResData[i] = data[4 * i] / 255;
}
Now the data is in a format that allows for far higher numeric resolution, so we can smooth that now. You could either adjust something like the StackBlur for the float32 use-case, use ndarrays and ndarray-gaussian-filter or implement something simple yourself. The basic idea is to find an average value for all the values in those uniformly colored plateaus.
Hope that helps, good luck :)
I'm worked with Three.JS before, but not on meshes. I think I am approaching my problem the right way, but I'm not sure.
The Goal
I'm trying to make a 3D blobby object that has specific verticies. The direction of the verticies are fixed, but their radius from center varies. You can imagine it sort of like an audio equalizer, except radial and in 3D.
I'm open to scrapping this approach and taking a totally different one if there's some easier way to do this.
Current Progress
I took this example and cleaned/modified it to my needs. Here's the HTML and JavaScript:
HTML (disco-ball.html)
<!DOCTYPE html>
<html>
<head>
<title>Disco Ball</title>
<script type="text/javascript" src="../libs/three.js"></script>
<script type="text/javascript" src="../libs/stats.js"></script>
<script type="text/javascript" src="../libs/ConvexGeometry.js"></script>
<script type="text/javascript" src="../libs/dat.gui.js"></script>
<style type='text/css'>
/* set margin to 0 and overflow to hidden, to go fullscreen */
body { margin: 0; overflow: hidden; }
</style>
</head>
<body>
<div id="Stats-output"></div>
<div id="WebGL-output"></div>
<script type="text/javascript" src="01-app.js"></script>
</body>
</html>
And the JavaScript (01-app.js):
window.onload = init;
const PARAMS = {
SHOW_SURFACE : true,
SHOW_POINTS : true,
SHOW_WIREFRAME : true,
SHOW_STATS : true
};
// once everything is loaded, we run our Three.js stuff.
function init() {
var renderParams = {
webGLRenderer : createWebGLRenderer(),
step : 0,
rotationSpeed : 0.007,
scene : new THREE.Scene(),
camera : createCamera(),
};
// Create the actual points.
var points = getPoints(
100, // Number of points (approximate)
10, // Unweighted radius
// Radius weights for a few points. This is a multiplier.
[2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2]
);
if (PARAMS.SHOW_STATS) {
renderParams.stats = initStats();
}
if (PARAMS.SHOW_SURFACE) {
renderParams.surface = getHullMesh(points);
renderParams.scene.add(renderParams.surface);
}
if (PARAMS.SHOW_POINTS) {
renderParams.sphereGroup = getSphereGroup(points);
renderParams.scene.add(sphereGroup);
}
render(renderParams);
}
function render(params) {
if (params.stats) {
params.stats.update();
}
if (params.sphereGroup) {
params.sphereGroup.rotation.y = params.step;
}
params.step += params.rotationSpeed;
if (params.surface) {
params.surface.rotation.y = params.step;
}
// render using requestAnimationFrame
requestAnimationFrame(function () {render(params)});
params.webGLRenderer.render(params.scene, params.camera);
}
// ******************************************************************
// Helper functions
// ******************************************************************
function getPoints (count, baseRadius, weightMap) {
// Because this is deterministic, we can pass in a weight map to adjust
// the radii.
var points = distributePoints(count,baseRadius,weightMap);
points.forEach((d,i) => {
points[i] = new THREE.Vector3(d[0],d[1],d[2]);
});
return points;
}
// A deterministic function for (approximately) evenly distributing n points
// over a sphere.
function distributePoints (count, radius, weightMap) {
// I'm not sure why I need this...
count *= 100;
var points = [];
var area = 4 * Math.PI * Math.pow(radius,2) / count;
var dist = Math.sqrt(area);
var Mtheta = Math.round(Math.PI / dist);
var distTheta = Math.PI / Mtheta
var distPhi = area / distTheta;
for (var m = 0; m < Mtheta; m++) {
let theta = (Math.PI * (m + 0.5)) / Mtheta;
let Mphi = Math.round((2 * Math.PI * Math.sin(theta)) / distPhi);
for (var n = 0; n < Mphi; n++) {
let phi = ((2 * Math.PI * n) / Mphi);
// Use the default radius, times any multiplier passed in through the
// weightMap. If no multiplier is present, use 1 to leave it
// unchanged.
points.push(createPoint(radius * (weightMap[points.length] || 1),theta,phi));
}
}
return points;
}
function createPoint (radius, theta, phi) {
var x = radius * Math.sin(theta) * Math.cos(phi);
var y = radius * Math.sin(theta) * Math.sin(phi);
var z = radius * Math.cos(theta);
return [Math.round(x), Math.round(y), Math.round(z)];
}
function createWebGLRenderer () {
// create a render and set the size
var webGLRenderer = new THREE.WebGLRenderer();
webGLRenderer.setClearColor(new THREE.Color(0xEEEEEE, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight);
webGLRenderer.shadowMapEnabled = true;
// add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement);
return webGLRenderer;
}
function createCamera () {
// create a camera, which defines where we're looking at.
var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
// position and point the camera to the center of the scene
camera.position.x = -30;
camera.position.y = 40;
camera.position.z = 50;
camera.lookAt(new THREE.Vector3(0, 0, 0));
return camera;
}
function getSphereGroup (points) {
sphereGroup = new THREE.Object3D();
var material = new THREE.MeshBasicMaterial({color: 0xFF0000, transparent: false});
points.forEach(function (point) {
var spGeom = new THREE.SphereGeometry(0.2);
var spMesh = new THREE.Mesh(spGeom, material);
spMesh.position.copy(point);
sphereGroup.add(spMesh);
});
return sphereGroup;
}
function getHullMesh (points) {
// use the same points to create a convexgeometry
var surfaceGeometry = new THREE.ConvexGeometry(points);
var surface = createMesh(surfaceGeometry);
return surface;
}
function createMesh(geom) {
// assign two materials
var meshMaterial = new THREE.MeshBasicMaterial({color: 0x666666, transparent: true, opacity: 0.25});
meshMaterial.side = THREE.DoubleSide;
var wireFrameMat = new THREE.MeshBasicMaterial({color: 0x0000ff});
wireFrameMat.wireframe = PARAMS.SHOW_WIREFRAME;
// create a multimaterial
var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial, wireFrameMat]);
return mesh;
}
function initStats() {
var stats = new Stats();
stats.setMode(0); // 0: fps, 1: ms
// Align top-left
stats.domElement.style.position = 'absolute';
stats.domElement.style.left = '0px';
stats.domElement.style.top = '0px';
document.getElementById("Stats-output").appendChild(stats.domElement);
return stats;
}
What I'm Missing
You can see that there are two points on the "ball" for which I've doubled the radius (big spikes). Of course, since I'm using a ConvexGeometry, the shape is convex... so a number of the points are hidden. What kind of ... non-convex geometry can I use to make those points no longer be hidden?
I would like to subdivide the mesh a bit so it's not simply vertex-to-vertex, but a bit smoother. How can I do that (the spikes less spikey and more blobby)?
I'd like to modify the mesh so different points spike different amounts every few seconds (I have some data arrays that describe how much). How do I modify the geometry after its been made? Ideally with some kind of tweening, but I can do without of that's extremely hard =)
Thanks!
Smooth and animate a mesh.
Three provides a huge range of options. These are just suggestions, your best bet is to read the Three documentation start point and find what suits you.
A mesh is just a set of 3D points and an array of indexes describing each triangle. Once you have built the mesh you only need to update the verts and let Three update the shader attributes, and the mesh normals
Your questions
Q1. Use Three.Geometry for the mesh.
Q2. As you are building the mesh you can use the curve helpers eg Three.CubicBezierCurve3 or Three.QuadraticBezierCurve3 or maybe your best option Three.SplineCurve
Another option is to use a modifier and create the simple mesh and then let Three subdivide the mesh for you. eg three example webgl modifier subdivision
Though not the fastest solution, if the vert count is low it will do this each frame without any loss of frame rate.
Q3. Using Three.Geometry you can can set the mesh morph targets, an array of vertices.
Another option is to use a modifier, eg three example webgl modifier subdivision
Or you can modify the vertices directly each frame.
for ( var i = 0, l = geometry.vertices.length; i < l; i ++ ) {
geometry.vertices[ i ].x = ?;
geometry.vertices[ i ].y = ?;
geometry.vertices[ i ].z = ?;
}
mesh.geometry.verticesNeedUpdate = true;
How you do it?
There are a zillion other ways to do this. Which is the best will depend on the load and amount of complexity you want to create. Spend some time and read the doc's, and experiment.
What I would do! maybe?
I am not too sure what you are trying to achieve but the following is a way of getting some life into the animation rather than the overdone curves that seem so ubiquitous these days.
So if the vert count is not too high I would use a Three.BufferGeometry and modify the verts each frame. Rather than use curves I would weight subdivision verts to follow a polynomial curve f(x) = x^2/(x^2 + (1-x)^2) where x is the normalized distance between two control verts (note don't use x=0.5 rather subdivide the mesh in > 2 times)
EG the two control points and two smoothing verts
// two control points
const p1 = {x,y,z};
const p2 = {x,y,z};
// two weighted points
// dx,dy,dz are deltas
// w is the weighted position s-curve
// wa, and wd are acceleration and drag coefficients. Try to keep their sum < 1
const pw1 = {x, y, z, dx, dy, dz, w : 1/3, wa : 0.1,wd : 0.7};
const pw2 = {x, y, z, dx, dy, dz, w : 2/3, wa : 0.1,wd : 0.7};
// Compute w
pw1.w = Math.pow(pw1.w,2) / ( Math.pow(pw1.w,2) + Math.pow(1 - pw1.w,2));
pw2.w = Math.pow(pw2.w,2) / ( Math.pow(pw2.w,2) + Math.pow(1 - pw2.w,2));
Then for each weighted point you can find the new delta and update the position
// do for x,y,z
x = (p2.x - p1.x); // these points are updated every frame
// get the new pw1 vert target position
x = p1.x + x * w;
// get new delta
pw1.dx += (x - pw1.x) * pw1.wa; // set delta
pw1.dx *= pw1.wd;
// set new position
pw1.x += pw1.dx;
Do for all weighted points then set geometry.vertices
The wa,wd coefficients will change the behaviour of the smoothing, you will have to play with these values to suit your own taste. Must be 0 <= (wa,wd) < 1 and the sum should be wa + wd < 1. High sumed values will result in oscillations, too high and the oscillations will be uncontrolled.
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.
Is there any way to move an object forward in Three.js?
Maybe I should convert the rotation.x,y,z to a vector, and deal with it. But I'm beginner, and I don't have any idea how to do it.
Object3D has some handy methods for that.
object.translateZ( 10 );
Please use above answer of #mrdoob, creator of ThreeJS:
object.translateZ( delta );
===OLD ANSWER===
A tutorial that worked for older ThreeJS version:
http://www.aerotwist.com/tutorials/getting-started-with-three-js/
// set position of YOUR_OBJECT
YOUR_OBJECT.position.x = 10;
YOUR_OBJECT.position.y = 50;
YOUR_OBJECT.position.z = 130;
More options:
var STEP = 10;
var newCubeMatrix = cube.matrix;
newCubeMatrix.identity();
//newCubeMatrix.multiplySelf(THREE.Matrix4.rotationYMatrix(cube.rotation.y));
newCubeMatrix.multiplySelf(THREE.Matrix4.translationMatrix(cube.position.x, cube.position.y, cube.position.z + STEP));
cube.updateMatrix();
details posted here https://gamedev.stackexchange.com/questions/7490/translate-object-in-world-space-usings-its-local-rotation
The camera is a point in space.
"Forward" is another point in space.
so you can simply use the coordinates of a second point, and make the camera location closer to the "forward" location.
however, you may also need to turn left and right, which might involve polar coordinates.
adjust these values for your convenience:
var scene;
var camera;
var playerDirection = 0;//angles 0 - 2pi
var dVector;
var angularSpeed = 0.01;
var playerSpeed = 0.075;
var playerBackwardsSpeed = playerSpeed * 0.4;
this function will initialize the scene:
function init(){
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 );
renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
camera.position.z = 5;
dVector = new THREE.Vector3( 0, 0, 0 ) ;
camera.lookAt( dVector );
animate();
}
movement of the player is stopped when the player presses the up key.
function key_up(event){
playerIsMovingForward = 0;
playerIsMovingBackwards = 0;
playerIsRotatingLeft = 0;
playerIsRotatingRight = 0;
playerGoesUp = 0;
playerGoesDown = 0;
}
when the player is moving, we update the position:
function updatePlayer(){
if(playerIsRotatingLeft){ // rotate left
playerDirection -= angularSpeed;
}
if(playerIsRotatingRight){ // rotate right
playerDirection += angularSpeed;
}
if(playerIsRotatingRight || playerIsRotatingLeft){
setPlayerDirection();
}
if(playerIsMovingForward){ // go forward
moveForward(playerSpeed);
}
if(playerIsMovingBackwards){ // go backwards
moveForward(-playerBackwardsSpeed);
}
}
We assume by forward you meant "using the WASD keys"
function key_down(event){
var W = 87;
var S = 83;
var A = 65;
var D = 68;
var minus = 189;
var plus = 187;
var k = event.keyCode;
console.log(k);
if(k == A){ // rotate left
playerIsRotatingLeft = 1;
}
if(k == D){ // rotate right
playerIsRotatingRight = 1;
}
if(k == W){ // go forward
playerIsMovingForward = 1;
}
if(k == S){ // go back
playerIsMovingBackwards = 1;
}
}
player will only move as fast as his browser.
so maybe adjust this code?
function animate() {
requestAnimationFrame( animate );
updatePlayer();
renderer.render( scene, camera );
}
this is the code that moves the camera into the position of the dVector object
and also repositions the direction vector (dVector), so that it is always forward from the camera.
function moveForward(speed){
var delta_x = speed * Math.cos(playerDirection);
var delta_z = speed * Math.sin(playerDirection);
var new_x = camera.position.x + delta_x;
var new_z = camera.position.z + delta_z;
camera.position.x = new_x;
camera.position.z = new_z;
var new_dx = dVector.x + delta_x;
var new_dz = dVector.z + delta_z;
dVector.x = new_dx;
dVector.z = new_dz;
camera.lookAt( dVector );
}
moving forward usually involves turning left and right, here is some code that does that, it also uses polar coordinates, to move the point in relation to the camera (which is the center of the "circle" by a given amount of degrees (in radians)
function setPlayerDirection(){
//direction changed.
var delta_x = playerSpeed * Math.cos(playerDirection);
var delta_z = playerSpeed * Math.sin(playerDirection);
var new_dx = camera.position.x + delta_x;
var new_dz = camera.position.z + delta_z;
dVector.x = new_dx;
dVector.z = new_dz;
console.log(dVector);
camera.lookAt( dVector );
}
animate();
I hope that helps.
Another option is to use Vector3's set method/function.
position.set(x, y, z);