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domitry/README.md

Last active May 28, 2020
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a demo of surface plot with three.js

3D Surface plot demo with three.js

alt text

<html lang="en">
<head>
<title>Plot Sample</title>
<link rel='stylesheet' href='index.css'>
</head>
<body>
<div id="stage"></div>
<script type="text/javascript" src="three.min.js"></script>
<script type="text/javascript" src="TrackballControls.js"></script>
<script type="text/javascript" src="surface_plot.js"></script>
</body>
var container, scene, camera, renderer, controls;
init();
initGraph();
animate();
function init(){
scene = new THREE.Scene();
var SCREEN_WIDTH=500, SCREEN_HEIGHT=500;
var VIEW_ANGLE=45, ASPECT=SCREEN_WIDTH/SCREEN_HEIGHT, NEAR=0.1, FAR=2000;
camera = new THREE.PerspectiveCamera(VIEW_ANGLE, ASPECT, NEAR, FAR);
scene.add(camera);
camera.position.set(0, 150, 400);
camera.lookAt(scene.position);
renderer = new THREE.WebGLRenderer({antialias:true});
renderer.setSize(SCREEN_WIDTH, SCREEN_HEIGHT);
container = document.getElementById('stage');
container.appendChild(renderer.domElement);
var positions = [[1,1,1],[-1,-1,1],[-1,1,1],[1,-1,1]];
for(var i=0;i<4;i++){
var light=new THREE.DirectionalLight(0xdddddd);
light.position.set(positions[i][0],positions[i][1],0.4*positions[i][2]);
scene.add(light);
}
initGrid();
controls = new THREE.TrackballControls( camera );
renderer.setClearColor( 0xffffff, 1 );
}
function initGrid(){
var BIGIN=-10, END=10, WIDTH=END-BIGIN;
var plane_geometry = new THREE.PlaneGeometry(WIDTH,WIDTH);
var plane_material = new THREE.MeshLambertMaterial({color:0xf0f0f0, shading: THREE.FlatShading, overdraw: 0.5, side: THREE.DoubleSide});
var plane = new THREE.Mesh(plane_geometry, plane_material);
scene.add(plane);
var geometry = new THREE.Geometry();
for(var i=BIGIN;i<=END;i+=2){
geometry.vertices.push(new THREE.Vector3(BIGIN,i,0));
geometry.vertices.push(new THREE.Vector3(END,i,0));
geometry.vertices.push(new THREE.Vector3(i,BIGIN,0));
geometry.vertices.push(new THREE.Vector3(i,END,0));
}
var material = new THREE.LineBasicMaterial( { color: 0x999999, opacity: 0.2 } );
var line = new THREE.Line(geometry, material);
line.type = THREE.LinePieces;
scene.add(line)
}
function initGraph(){
data = initData();
var geometry = new THREE.Geometry();
var colors = [];
var width = data.length, height = data[0].length;
data.forEach(function(col){
col.forEach(function(val){
geometry.vertices.push(new THREE.Vector3(val.x,val.y,val.z))
colors.push(getColor(2.5,0,val.z));
});
});
var offset = function(x,y){
return x*width+y;
}
for(var x=0;x<width-1;x++){
for(var y=0;y<height-1;y++){
var vec0 = new THREE.Vector3(), vec1 = new THREE.Vector3(), n_vec = new THREE.Vector3();
// one of two triangle polygons in one rectangle
vec0.subVectors(geometry.vertices[offset(x,y)],geometry.vertices[offset(x+1,y)]);
vec1.subVectors(geometry.vertices[offset(x,y)],geometry.vertices[offset(x,y+1)]);
n_vec.crossVectors(vec0,vec1).normalize();
geometry.faces.push(new THREE.Face3(offset(x,y),offset(x+1,y),offset(x,y+1), n_vec, [colors[offset(x,y)],colors[offset(x+1,y)],colors[offset(x,y+1)]]));
geometry.faces.push(new THREE.Face3(offset(x,y),offset(x,y+1),offset(x+1,y), n_vec.negate(), [colors[offset(x,y)],colors[offset(x,y+1)],colors[offset(x+1,y)]]));
// the other one
vec0.subVectors(geometry.vertices[offset(x+1,y)],geometry.vertices[offset(x+1,y+1)]);
vec1.subVectors(geometry.vertices[offset(x,y+1)],geometry.vertices[offset(x+1,y+1)]);
n_vec.crossVectors(vec0,vec1).normalize();
geometry.faces.push(new THREE.Face3(offset(x+1,y),offset(x+1,y+1),offset(x,y+1), n_vec, [colors[offset(x+1,y)],colors[offset(x+1,y+1)],colors[offset(x,y+1)]]));
geometry.faces.push(new THREE.Face3(offset(x+1,y),offset(x,y+1),offset(x+1,y+1), n_vec.negate(), [colors[offset(x+1,y)],colors[offset(x,y+1)],colors[offset(x+1,y+1)]]));
}
}
var material = new THREE.MeshLambertMaterial({ vertexColors: THREE.VertexColors});
var mesh = new THREE.Mesh(geometry, material);
scene.add(mesh);
}
function getColor(max,min,val){
var MIN_L=40,MAX_L=100;
var color = new THREE.Color();
var h = 0/240;
var s = 80/240;
var l = (((MAX_L-MIN_L)/(max-min))*val)/240;
color.setHSL(h,s,l);
return color;
}
function initWireframe(){
}
function initData(){
var BIGIN=-10, END=10;
var data = new Array();
for(var x=BIGIN;x<END;x++){
var row = [];
for(var y=BIGIN;y<END;y++){
z = 2.5*(Math.cos(Math.sqrt(x*x+y*y))+1);
row.push({x: x, y: y, z: z});
}
data.push(row);
}
return data;
}
function animate(){
requestAnimationFrame(animate);
render();
controls.update();
}
function render(){
renderer.render(scene, camera);
}
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