Javascript 三.曲线路径和自定义标记
我正在使用Three.JS创建一个游戏，我已经建模并成功导入了在Sketchup中创建的城市。我现在需要动态添加一些“跟随我”箭头（根据下面模型中的黄色箭头）。我相信我可能需要使用Three.CurvePath来实现这一点，但我不确定这是否是最好的方法-我是否需要手动建模路径并计算每个箭头对象的切线，以便它们自然指向拐角（根据模型中的左转） 希望这有意义 我可能有个解决办法。 有一段时间没有使用three.js了，所以不确定这是否是最优雅的解决方案。 我从以下内容开始：Javascript 三.曲线路径和自定义标记,javascript,three.js,Javascript,Three.js,我正在使用Three.JS创建一个游戏，我已经建模并成功导入了在Sketchup中创建的城市。我现在需要动态添加一些“跟随我”箭头（根据下面模型中的黄色箭头）。我相信我可能需要使用Three.CurvePath来实现这一点，但我不确定这是否是最好的方法-我是否需要手动建模路径并计算每个箭头对象的切线，以便它们自然指向拐角（根据模型中的左转） 希望这有意义 我可能有个解决办法。 有一段时间没有使用three.js了，所以不确定这是否是最优雅的解决方案。 我从以下内容开始： 如何按程序构建路径（使
var roundedRectShape = new THREE.Shape();
( function roundedRect( ctx, x, y, width, height, radius ){
ctx.moveTo( x, y + radius );
ctx.lineTo( x, y + height - radius );
ctx.quadraticCurveTo( x, y + height, x + radius, y + height );
ctx.lineTo( x + width - radius, y + height) ;
ctx.quadraticCurveTo( x + width, y + height, x + width, y + height - radius );
ctx.lineTo( x + width, y + radius );
ctx.quadraticCurveTo( x + width, y, x + width - radius, y );
ctx.lineTo( x + radius, y );
ctx.quadraticCurveTo( x, y, x, y + radius );
} )( roundedRectShape, 0, 0, 200, 200, 20 );
getPoint（t）Math.atan2（）t = (t + s)%1.0;//increment t while maintaining it between 0.0 and 1.0
var p = path.getPoint(t);//point at t
var pn = path.getPoint((t+s)%1.0);//point at next t iteration
if(p != null && pn != null){
//move to current position
arrow.position.x = p.x;
arrow.position.y = p.y;
//get orientation based on next position
arrow.rotation.z = Math.atan2(pn.y-p.y,pn.x-p.x);
}
<!DOCTYPE html>
<html lang="en">
<head>
<title>path interpolation</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>
<canvas id="debug" style="position:absolute; left:100px"></canvas>
<script src="../build/three.min.js"></script>
<script src="js/libs/stats.min.js"></script>
<script>
var container, stats;
var camera, scene, renderer;
var text, plane;
var targetRotation = 0;
var targetRotationOnMouseDown = 0;
var mouseX = 0;
var mouseXOnMouseDown = 0;
var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;
init();
animate();
var t = 0.0;//traversal on path
var s = 0.001;//speed of traversal
var arrow;//mesh to move/rotate on path
var path;//Path object to traverse
function init() {
container = document.createElement( 'div' );
document.body.appendChild( container );
camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1000 );
camera.position.set( 0, 150, 500 );
scene = new THREE.Scene();
parent = new THREE.Object3D();
parent.position.y = 50;
scene.add( parent );
arrow = new THREE.Mesh( new THREE.CubeGeometry(20,10,10),new THREE.MeshBasicMaterial({color: 0x009900}));
parent.add(arrow);
//this is helpful as a visual aid but not crucial
function addShape( shape, extrudeSettings, color, x, y, z, rx, ry, rz, s ) {
var points = shape.createPointsGeometry();
var spacedPoints = shape.createSpacedPointsGeometry( 50 );
// transparent line from equidistance sampled points
var line = new THREE.Line( spacedPoints, new THREE.LineBasicMaterial( { color: color, opacity: 0.2 } ) );
line.rotation.set( rx, ry, rz );
parent.add( line );
// equidistance sampled points
var pgeo = spacedPoints.clone();
var particles2 = new THREE.ParticleSystem( pgeo, new THREE.ParticleBasicMaterial( { color: color, size: 2, opacity: 0.5 } ) );
particles2.rotation.set( rx, ry, rz );
parent.add( particles2 );
}
// Rounded rectangle
//generating the path and populating it is crucial tough
var roundedRectShape = new THREE.Shape();
( function roundedRect( ctx, x, y, width, height, radius ){
ctx.moveTo( x, y + radius );
ctx.lineTo( x, y + height - radius );
ctx.quadraticCurveTo( x, y + height, x + radius, y + height );
ctx.lineTo( x + width - radius, y + height) ;
ctx.quadraticCurveTo( x + width, y + height, x + width, y + height - radius );
ctx.lineTo( x + width, y + radius );
ctx.quadraticCurveTo( x + width, y, x + width - radius, y );
ctx.lineTo( x + radius, y );
ctx.quadraticCurveTo( x, y, x, y + radius );
} )( roundedRectShape, 0, 0, 200, 200, 20 );
path = roundedRectShape;
var extrudeSettings = { amount: 20 }; // bevelSegments: 2, steps: 2 , bevelSegments: 5, bevelSize: 8, bevelThickness:5
extrudeSettings.bevelEnabled = true;
extrudeSettings.bevelSegments = 2;
extrudeSettings.steps = 2;
addShape( roundedRectShape, extrudeSettings, 0x000000, -150, 150, 0, 0, 0, 0, 1 );
renderer = new THREE.WebGLRenderer( { antialias: true } );
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );
stats = new Stats();
stats.domElement.style.position = 'absolute';
stats.domElement.style.top = '0px';
container.appendChild( stats.domElement );
document.addEventListener( 'mousedown', onDocumentMouseDown, false );
document.addEventListener( 'touchstart', onDocumentTouchStart, false );
document.addEventListener( 'touchmove', onDocumentTouchMove, false );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
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 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 );
render();
stats.update();
}
function render() {
t = (t + s)%1.0;//increment t while maintaining it between 0.0 and 1.0
var p = path.getPoint(t);//point at t
var pn = path.getPoint((t+s)%1.0);//point at next t iteration
if(p != null && pn != null){
//move to current position
arrow.position.x = p.x;
arrow.position.y = p.y;
//get orientation based on next position
arrow.rotation.z = Math.atan2(pn.y-p.y,pn.x-p.x);
}
parent.rotation.y += ( targetRotation - parent.rotation.y ) * 0.05;
renderer.render( scene, camera );
}
</script>
</body>
</html>
形状