解決策があるかもしれません。three.js をしばらく使用していないので、これが最も洗練されたソリューションかどうかはわかりません。それが示すので、私は形状の例から始めました:
- プロシージャルにパスを作成する方法 (曲線も処理するコマンドを使用)
- そのようなパスからポイントを抽出する方法
したがって、問題を次のように分割しました。
- パスの生成
- パスのトラバースと補間 (位置と回転)
スクリーンショットの一部に似た角丸長方形の定義を再利用したパスの生成。
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 );
パスは角丸四角形ではないかもしれませんが、使用可能なタイプの曲線関数 (quadraticCurveTo、bezierCurveTo、splineThru) は非常に便利です。
頭に浮かぶもう 1 つのアイデアは、Ruby スクリプトを使用してパス座標を Sketchup から three.js にエクスポートすることです。それをゼロから作成するか、既存のスクリプトを使用します。これはグーグル
で簡単に見つけられるものです。
道をたどる
幸い、three.js はすでにこれをパスを通じて実装していますgetPoint(t)
。ここで、t はパス上のトラバーサルを表す 0.0 から 1.0 までの数値です。したがって、位置を取得することは、パス上の次の補間位置を取得するのと同じくらい簡単です。次にMath.atan2()
、回転を取得するために使用するだけの問題です:
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);
}
結論として、形状の例に基づいて three.js でパスを生成およびトラバースする方法を示す基本的な例 (矢印形状の代わりに立方体を使用) を以下に示します。
<!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>
このページに直接実行可能なスニペットを追加すると思いました:
var container;
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 arrows;//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 );
arrows = [];
for(var i = 0 ; i < 50; i++){
arrows[i] = new THREE.Mesh( new THREE.CubeGeometry(10,5,5),new THREE.MeshBasicMaterial({color: 0x009900}));
parent.add(arrows[i]);
}
//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 );
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();
}
function render() {
t = (t + s)%1.0;//increment t while maintaining it between 0.0 and 1.0 - could map mouse x position/window width for fun :)
for(var i = 0 ; i < 50; i++){//for each box
var ti = ((i/50.0)+t)%1.0;//compute the traversval including each box's own offset on the path
var p = path.getPoint(ti);//point at t
var pn = path.getPoint((ti+s)%1.0);//point at next t iteration
if(p != null && pn != null){
//move to current position
arrows[i].position.x = p.x;
arrows[i].position.y = p.y;
//get orientation based on next position
arrows[i].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 );
}
body {
font-family: Monospace;
background-color: #f0f0f0;
margin: 0px;
overflow: hidden;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r71/three.min.js"></script>