我创建了一个管几何图形，其中包含从JSON格式的外部javascript文件加载的200个点的数据。请找到以下代码。
<!DOCTYPE html>
<html lang="en">
<head>
<title>3d Model using HTML5 and three.js</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<style>
body {
font-family: Monospace;
background-color: #f0f0f0;
margin: 0px;
overflow: hidden;
}
</style>
</head>
<body>
<input type="button" value="plot" onClick="return plotPath();" />
<script src="three.min.js" type="text/javascript"></script>
<script src="Curve.js" type="text/javascript"></script>
<script src="TubeGeometry.js" type="text/javascript"></script>
<script src="Stats.js" type="text/javascript"></script>
<script src="Detector.js" type="text/javascript"></script>
<script src="path.js" type="text/javascript"></script>
<script>
// variables
var container, stats;
var camera, scene, renderer, controls, stats;
var text, plane, tube, tubeMesh, parent;
var targetRotation = 0;
var targetRotationOnMouseDown = 0;
var mouseX = 0;
var mouseXOnMouseDown = 0;
var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;
var radius = 600;
var theta = 0;
var PI2 = Math.PI * 2;
function plotPath()
{
var obj = getPath();
var segments = 50;
var closed = false;
var debug = true;
var radiusSegments = 12;
var tube;
var points = [];
var x=0,y=0,z=0;
for(var i=0; i<obj.path.length; i++)
{
console.log(obj.path[i].point);
points.push(obj.path[i].point);
extrudePath = new THREE.SplineCurve3(points);
extrudePath.dynamic = true;
tube = new THREE.TubeGeometry(extrudePath, segments, 2, radiusSegments, closed, debug);
tube.dynamic = true;
tubeMesh = new THREE.Mesh(tube ,new THREE.MeshBasicMaterial({
color: 0x000000, side: THREE.DoubleSide,
opacity: 0.5, transparent: true, wireframe: true}));
tubeMesh.__dirtyVertices = true;
tubeMesh.dynamic = true;
parent = new THREE.Object3D();
parent.position.y = 100;
if ( tube.debug ) tubeMesh.add( tube.debug );
parent.add( tubeMesh );
}
scene.add( tubeMesh );
scene.add(parent);
animate();
}
init();
function init(){
// container
container = document.createElement( 'div' );
document.body.appendChild( container );
// renderer
renderer = new THREE.WebGLRenderer( { antialias: true } );
renderer.setClearColorHex(0xEEEEEE, 1.0);
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.clear();
container.appendChild( renderer.domElement );
// camera
camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 10000 );
camera.position.set(-100,75,75);
// scene
scene = new THREE.Scene();
camera.lookAt(scene.position);
// light
scene.add( new THREE.AmbientLight( 0x404040 ) );
light = new THREE.DirectionalLight( 0xffffff );
light.position.set( 0, 1, 0 );
scene.add( light );
// CONTROLS
controls = new THREE.TrackballControls( camera );
// Grid
geometry = new THREE.Geometry();
geometry.vertices.push( new THREE.Vector3( - 500, 0, 0 ) );
geometry.vertices.push( new THREE.Vector3( 500, 0, 0 ) );
for ( var i = 0; i <= 20; i ++ ) {
line = new THREE.Line( geometry, new THREE.LineBasicMaterial( { color: 0x000000, opacity: 0.2 } ) );
line.position.z = ( i * 50 ) - 500;
scene.add( line );
line = new THREE.Line( geometry, new THREE.LineBasicMaterial( { color: 0x000000, opacity: 0.2 } ) );
line.position.x = ( i * 50 ) - 500;
line.rotation.y = 90 * Math.PI / 180;
scene.add( line );
}
// projector
projector = new THREE.Projector();
plotPath();
// stats
stats = new Stats();
stats.domElement.style.position = 'absolute';
stats.domElement.style.top = '0px';
container.appendChild( stats.domElement );
document.addEventListener( 'mousedown', onDocumentMouseDown, false );
document.addEventListener( 'mouseover', onDocumentMouseOver, false );
document.addEventListener( 'touchstart', onDocumentTouchStart, false );
document.addEventListener( 'touchmove', onDocumentTouchMove, false );
window.addEventListener('DOMMouseScroll', mousewheel, false);
window.addEventListener('mousewheel', mousewheel, false);
window.addEventListener( 'resize', onWindowResize, false );
}
function mousewheel(event) {
var fovMAX = 160;
var fovMIN = 1;
camera.fov -= event.wheelDeltaY * 0.05;
camera.fov = Math.max( Math.min( camera.fov, fovMAX ), fovMIN );
camera.projectionMatrix = new THREE.Matrix4().makePerspective(camera.fov, window.innerWidth / window.innerHeight, camera.near, camera.far);
}
function onWindowResize() {
camera.left = window.innerWidth / - 2;
camera.right = window.innerWidth / 2;
camera.top = window.innerHeight / 2;
camera.bottom = window.innerHeight / - 2;
camera.aspect = window.innerWidth / window.innerHeight;
renderer.setSize( window.innerWidth, window.innerHeight );
}
function onDocumentMouseDown( event ) {
event.preventDefault();
document.addEventListener( 'mousemove', onDocumentMouseMove, false );
document.addEventListener( 'mouseup', onDocumentMouseUp, false );
document.addEventListener( 'mouseout', onDocumentMouseOut, false );
mouseXOnMouseDown = event.clientX - windowHalfX;
targetRotationOnMouseDown = targetRotation;
}
function onDocumentMouseMove( event ) {
mouseX = event.clientX - windowHalfX;
targetRotation = targetRotationOnMouseDown + ( mouseX - mouseXOnMouseDown ) * 0.02;
}
function onDocumentMouseUp( event ) {
document.removeEventListener( 'mousemove', onDocumentMouseMove, false );
document.removeEventListener( 'mouseup', onDocumentMouseUp, false );
document.removeEventListener( 'mouseout', onDocumentMouseOut, false );
}
function onDocumentMouseOut( event ) {
document.removeEventListener( 'mousemove', onDocumentMouseMove, false );
document.removeEventListener( 'mouseup', onDocumentMouseUp, false );
document.removeEventListener( 'mouseout', onDocumentMouseOut, false );
}
function onDocumentMouseOver( event ) {
document.removeEventListener( 'mousemove', onDocumentMouseMove, false );
document.removeEventListener( 'mouseup', onDocumentMouseUp, false );
document.removeEventListener( 'mouseout', onDocumentMouseOut, false );
}
function onDocumentTouchStart( event ) {
if ( event.touches.length === 1 ) {
event.preventDefault();
mouseXOnMouseDown = event.touches[ 0 ].pageX - windowHalfX;
targetRotationOnMouseDown = targetRotation;
}
}
function onDocumentTouchMove( event ) {
if ( event.touches.length === 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
targetRotation = targetRotationOnMouseDown + ( mouseX - mouseXOnMouseDown ) * 0.05;
}
}
function animate() {
requestAnimationFrame( animate, renderer.domElement );
render();
update();
}
function update(){
controls.update();
}
function toCameraCoords(position) {
return camera.matrixWorldInverse.multiplyVector3(position.clone());
}
function render() {
tubeMesh.rotation.y += ( targetRotation - tubeMesh.rotation.y ) * 0.15;
camera.lookAt(scene.position);
camera.updateMatrixWorld();
renderer.render( scene, camera );
}
</script>
</body>
</html>
当我使用鼠标滚轮放大时，相机将在管的起始点放大。如何使管几何形状完全缩放，换句话说，管的任何部分都可以缩放？
答案 0 :(得分：4)
与任何传统的现实生活相机一样，您可以通过调用setLens方法更改THREE.PerspectiveCamera的焦距（缩放）。我发现这种方式非常直观，而且比移动相机进行放大/缩小要简单得多。
以下是three.js中的方法docs：
/**
* Uses Focal Length (in mm) to estimate and set FOV
* 35mm (fullframe) camera is used if frame size is not specified;
* Formula based on http://www.bobatkins.com/photography/technical/field_of_view.html
*/
THREE.PerspectiveCamera.prototype.setLens = function ( focalLength, frameHeight )
...
以下是一个示例用法：
var focalLength = 25.734; // equivalent to FOV=50
$('#scene').mousewheel(function (event, delta, deltaX, deltaY) {
event.preventDefault();
focalLength += deltaY;
camera.setLens(focalLength);
});
方法jQuery.fn.mousewheel由Mousewheel Plugin提供。
答案 1 :(得分：1)
document.body.addEventListener( 'mousewheel', mousewheel, false );
document.body.addEventListener( 'DOMMouseScroll', mousewheel, false ); // firefox
function mousewheel( e ) {
var d = ((typeof e.wheelDelta != "undefined")?(-e.wheelDelta):e.detail);
d = 100 * ((d>0)?1:-1);
var cPos = camera.position;
if (isNaN(cPos.x) || isNaN(cPos.y) || isNaN(cPos.y))
return;
var r = cPos.x*cPos.x + cPos.y*cPos.y;
var sqr = Math.sqrt(r);
var sqrZ = Math.sqrt(cPos.z*cPos.z + r);
var nx = cPos.x + ((r==0)?0:(d * cPos.x/sqr));
var ny = cPos.y + ((r==0)?0:(d * cPos.y/sqr));
var nz = cPos.z + ((sqrZ==0)?0:(d * cPos.z/sqrZ));
if (isNaN(nx) || isNaN(ny) || isNaN(nz))
return;
cPos.x = nx;
cPos.y = ny;
cPos.z = nz;
}
甚至更简单地只调整相机：
var mousewheel = function ( e ) {
var d = ((typeof e.wheelDelta != "undefined")?(-e.wheelDelta):e.detail);
d = 100 * ((d>0)?1:-1);
var cPos = camera.position;
if (isNaN(cPos.x) || isNaN(cPos.y) || isNaN(cPos.y)) return;
// Your zomm limitation
// For X axe you can add anothers limits for Y / Z axes
if (cPos.x > _YOUR_ZOOM_MIN_X_ || cPos.x < _YOUR_ZOOM_MAX_X_ ){
return ;
}
mb = d>0 ? 1.1 : 0.9;
cPos.x = cPos.x * mb;
cPos.y = cPos.y * mb;
cPos.z = cPos.z * mb;
}