三个拉伸形状中的奇数瑕疵和空纹理。js

Question

我试图通过使用Three.js挤压形状来给SVG路径（lineto和moveto）带来3D感觉，但这个过程会导致一些我无法删除的伪影。

什么会导致渲染的3D形状中出现奇怪的瑕疵？有没有办法去除它们？

工件在下面的示例图像中用箭头标记。

现场示例如下：http://jsfiddle.net/pHn2B/24/

代码在这里：

// Picking with Callback

// three.js r.52
var container,
    info,
    camera,
    scene,
    light,
    geometry,
    mesh,
    projector,
    renderer,
    controls;
    objects = [];

// dom
container = document.createElement( 'div' );
document.body.appendChild( container );

// info
info = document.createElement( 'div' );
info.style.position = 'absolute';
info.style.top = '10px';
info.style.width = '100%';
info.style.textAlign = 'center';
info.innerHTML = "drag to rotate camera; click to select";
container.appendChild( info );

// renderer
renderer = new THREE.CanvasRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );

// scene
scene = new THREE.Scene();

// camera
camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 10000 );
camera.position.set( 0, 300, 500 );
scene.add( camera );

// controls
controls = new THREE.OrbitControls( camera );

// light
scene.add( new THREE.AmbientLight( 0x222222 ) );

// light
light = new THREE.PointLight( 0xaaaaaa );
light.position = camera.position;
scene.add( light );

// geometry
geometry = new THREE.CubeGeometry( 100, 100, 500 );

// material
material = new THREE.MeshLambertMaterial( { color: 0xff0000, ambient: 0xff0000, overdraw: true } );

// mesh
mesh = new THREE.Mesh( geometry, material );
mesh.position.set( -100, -100, 200 );
mesh.name = "Red Object";
mesh.callback = function() { info.innerHTML = this.name; }
scene.add( mesh );

objects.push( mesh );

// geometry
////////////
    // CUSTOM //
    ////////////

var starPoints2 = new THREE.Shape();

starPoints2.moveTo(307.94,275.49);
starPoints2.lineTo(296.26,275.23);
starPoints2.lineTo(286.64,272.99);
starPoints2.lineTo(279.78,269.31);
starPoints2.lineTo(274.14,263.55);
starPoints2.lineTo(271.65,260.21);
starPoints2.lineTo(269.2,261.06);
starPoints2.lineTo(254.83,268.51);
starPoints2.lineTo(242.11,272.97);
starPoints2.lineTo(227.59,275.23);
starPoints2.lineTo(209.91,275.48);
starPoints2.lineTo(197.47,273.63);
starPoints2.lineTo(187.91,270.13);
starPoints2.lineTo(180.48,265.09);
starPoints2.lineTo(175.32,258.88);
starPoints2.lineTo(172.2,251.44);
starPoints2.lineTo(171.1,242.23);
starPoints2.lineTo(172.24,233.63);
starPoints2.lineTo(175.49,226.24);
starPoints2.lineTo(181,219.54);
starPoints2.lineTo(189.42,213.3);
starPoints2.lineTo(201.36,207.73);
starPoints2.lineTo(217.23,203.25);
starPoints2.lineTo(238.28,200.1);
starPoints2.lineTo(269.37,198.47);
starPoints2.lineTo(269.98,182.93);
starPoints2.lineTo(268.74,171.32);
starPoints2.lineTo(266.05,163.7);
starPoints2.lineTo(261.58,157.72);
starPoints2.lineTo(255.24,153.24);
starPoints2.lineTo(247.06,150.32);
starPoints2.lineTo(235.44,149.13);
starPoints2.lineTo(224.71,150.05);
starPoints2.lineTo(215.91,153);
starPoints2.lineTo(210.23,156.86);
starPoints2.lineTo(207.64,160.85);
starPoints2.lineTo(207.19,165.28);
starPoints2.lineTo(209.34,169.86);
starPoints2.lineTo(212.01,174.15);
starPoints2.lineTo(212.14,177.99);
starPoints2.lineTo(209.8,181.78);
starPoints2.lineTo(204.22,185.79);
starPoints2.lineTo(197.62,187.68);
starPoints2.lineTo(188.65,187.43);
starPoints2.lineTo(182.41,185.39);
starPoints2.lineTo(178.45,181.77);
starPoints2.lineTo(176.2,176.9);
starPoints2.lineTo(176.03,170.64);
starPoints2.lineTo(178.2,164.13);
starPoints2.lineTo(183.09,157.69);
starPoints2.lineTo(191.04,151.36);
starPoints2.lineTo(202.01,145.82);
starPoints2.lineTo(216.09,141.57);
starPoints2.lineTo(232.08,139.24);
starPoints2.lineTo(250.07,139.18);
starPoints2.lineTo(266.13,141.23);
starPoints2.lineTo(279.05,145.06);
starPoints2.lineTo(289.15,150.3);
starPoints2.lineTo(295.91,156.19);
starPoints2.lineTo(300.73,163.41);
starPoints2.lineTo(303.85,172.47);
starPoints2.lineTo(305.07,183.78);
starPoints2.lineTo(305.07,241.97);
starPoints2.lineTo(306,251.51);
starPoints2.lineTo(308.18,256.39);
starPoints2.lineTo(311.72,259.09);
starPoints2.lineTo(317.31,260.01);
starPoints2.lineTo(324.71,259.01);
starPoints2.lineTo(332.45,255.86);
starPoints2.lineTo(335.57,257.53);
starPoints2.lineTo(337.6,260.44);
starPoints2.lineTo(336.94,262.33);
starPoints2.lineTo(328.27,268.74);
starPoints2.lineTo(317.89,273.41);
starPoints2.lineTo(307.94,275.49);
/*
starPoints2.moveTo(245.79,125.33);
starPoints2.lineTo(232.93,124.53);
starPoints2.lineTo(222.21,121.74);
starPoints2.lineTo(213.14,117.11);
starPoints2.lineTo(207.36,111.92);
starPoints2.lineTo(203.7,105.75);
starPoints2.lineTo(201.94,98.18);
starPoints2.lineTo(202.34,90.12);
starPoints2.lineTo(204.86,83.4);
starPoints2.lineTo(210.01,76.81);
starPoints2.lineTo(217.49,71.33);
starPoints2.lineTo(227.17,67.31);
starPoints2.lineTo(238.35,65.2);
starPoints2.lineTo(243.99,64.95);
starPoints2.lineTo(255.92,66.06);
starPoints2.lineTo(266.21,69.28);
starPoints2.lineTo(274.98,74.44);
starPoints2.lineTo(280.64,80.19);
starPoints2.lineTo(284.02,86.85);
starPoints2.lineTo(285.26,94.52);
starPoints2.lineTo(284.27,102.84);
starPoints2.lineTo(281.24,109.66);
starPoints2.lineTo(276.03,115.43);
starPoints2.lineTo(267.89,120.46);
starPoints2.lineTo(257.68,123.93);
starPoints2.lineTo(245.79,125.33);
*/
var smileyEye1Path = new THREE.Path();

smileyEye1Path.moveTo(221.69,258.13);
smileyEye1Path.lineTo(215.2,255.08);
smileyEye1Path.lineTo(210.86,250.57);
smileyEye1Path.lineTo(208.4,244.49);
smileyEye1Path.lineTo(207.92,237.03);
smileyEye1Path.lineTo(209.69,230.71);
smileyEye1Path.lineTo(213.82,224.85);
smileyEye1Path.lineTo(220.9,219.34);
smileyEye1Path.lineTo(230.95,214.67);
smileyEye1Path.lineTo(245.76,210.86);
smileyEye1Path.lineTo(266.59,208.36);
smileyEye1Path.lineTo(269.48,208.76);
smileyEye1Path.lineTo(269.99,212.88);
smileyEye1Path.lineTo(269.99,244.81);
smileyEye1Path.lineTo(269.34,247.02);
smileyEye1Path.lineTo(266.07,250.04);
smileyEye1Path.lineTo(255.27,255.23);
smileyEye1Path.lineTo(242.52,258.58);
smileyEye1Path.lineTo(230.57,259.43);
smileyEye1Path.lineTo(221.69,258.13);

/*
smileyEye1Path.moveTo(238.44,116.65);
smileyEye1Path.lineTo(231.99,114.29);
smileyEye1Path.lineTo(227.23,110.22);
smileyEye1Path.lineTo(223.94,104.53);
smileyEye1Path.lineTo(222.41,96.92);
smileyEye1Path.lineTo(223.05,88.57);
smileyEye1Path.lineTo(225.65,82.21);
smileyEye1Path.lineTo(230.07,77.36);
smileyEye1Path.lineTo(235.93,74.4);
smileyEye1Path.lineTo(243.68,73.34);
smileyEye1Path.lineTo(246.08,73.43);
smileyEye1Path.lineTo(253.37,75.08);
smileyEye1Path.lineTo(258.65,78.43);
smileyEye1Path.lineTo(262.47,83.41);
smileyEye1Path.lineTo(264.59,90.25);
smileyEye1Path.lineTo(264.64,98.93);
smileyEye1Path.lineTo(262.63,106.12);
smileyEye1Path.lineTo(258.87,111.5);
smileyEye1Path.lineTo(253.73,115.1);
smileyEye1Path.lineTo(246.81,116.94);
smileyEye1Path.lineTo(238.44,116.65);
*/
var starShape = starPoints2;

starShape.holes.push( smileyEye1Path );

    var extrusionSettings = {
        //size: 1, height: 1, curveSegments: 100, step = 10,
        // font, weight, style,
        amount:20,
        bevelEnabled: true, 
        bevelThickness: 0.5, 
        bevelSize: 0.5,
        bevelSegments: 8,
        // extrudePath:
        // bendPath:
        material: 0,
        extrudeMaterial: 1
        //,
        //uvGenerator: BoundingUVGenerator
       //uvGenerator: THREE.ExtrudeGeometry.WorldUVGenerator
    };

    var starGeometry = new THREE.ExtrudeGeometry( starShape, extrusionSettings );

    var materialFront = new THREE.MeshLambertMaterial( { color: 0xffff00, ambient: 0xffff00, overdraw: false, transparent:false, opacity: 1.0, side: THREE.DoubleSide } );
    var materialSide = new THREE.MeshLambertMaterial( { color: 0xff8800, ambient: 0xff8800, overdraw: false, transparent:false, opacity: 1.0, side: THREE.DoubleSide } );

//var crateTexture = new THREE.ImageUtils.loadTexture( 'http://www.kahkonen.com/asiakkaat/crate2.gif');
//var crateTexture = new THREE.ImageUtils.generateDataTexture(10,10,{r:255,g:0,b:0});

//var materialFront = new THREE.MeshBasicMaterial( { map: crateTexture } );

var materialArray = [ materialFront, materialSide ];
var materialArray = [ materialFront, materialSide ];

var starMaterial = new THREE.MeshFaceMaterial(materialArray);

    var star = new THREE.Mesh( starGeometry, starMaterial );

    star.position.set(-150,-150,0);
    scene.add(star);
/*  
    // add a wireframe to model
    var wireframeTexture = new THREE.MeshBasicMaterial( { color: 0x000000, wireframe: true, transparent: false } ); 
    var star = new THREE.Mesh( starGeometry, wireframeTexture );
    star.position.set(50,10,0);
    scene.add(star);
*/
objects.push( star );

// projector
projector = new THREE.Projector();

// listeners
document.addEventListener( 'mousedown', onDocumentMouseDown, false)

// keyboard handler
function onDocumentMouseDown( event ) {

    event.preventDefault();

    var vector = new THREE.Vector3( 
        ( event.clientX / window.innerWidth ) * 2 - 1, 
        - ( event.clientY / window.innerHeight ) * 2 + 1, 
        0.5 );

    projector.unprojectVector( vector, camera );

    var ray = new THREE.Ray( camera.position, vector.subSelf( camera.position ).normalize() );

    var intersects = ray.intersectObjects( objects );    

    if ( intersects.length > 0 ) {

        intersects[0].object.callback();

    }

}

// render
function render() {

    controls.update()

    renderer.render( scene, camera );
}

// animate            
(function animate() {

    requestAnimationFrame( animate );
    render();
}());

我尝试通过附加纹理来移除瑕疵，但纹理根本没有显示：

另一个问题（可能与伪像问题有关，也可能与伪像问题无关）是背景可以通过边缘看到。

纹理不是必须的，但是去除工件是必须的。

下面是我用来添加纹理的代码以及小提琴中的完整代码（链接在代码之后）：

var=新的三个。ImageUtils。loadTexture（'http://www.kahkonen.com/asiakkaat/crate.gif'); var=新的三个。ImageUtils。生成态结构（10,10，{r:255，g:0，b:0}）；var materialFront=新的三个。MeshBasicMaterial（{map:crateTexture}）

http://jsfiddle.net/pHn2B/27/代码

样本图像来自Chrome。同样的行为也发生在Firefox中。




Answer 1

我以前也有同样的问题
我还替换了成员函数generateSedWallUV（）
这些行：

if ( Math.abs( ay - by ) < 0.01 ) {
            return [
                new THREE.Vector2( ax, 1 - az ),
                new THREE.Vector2( bx, 1 - bz ),
                new THREE.Vector2( cx, 1 - cz ),
                new THREE.Vector2( dx, 1 - dz )
            ];
} else {
            return [
                new THREE.Vector2( ay, 1 - az ),
                new THREE.Vector2( by, 1 - bz ),
                new THREE.Vector2( cy, 1 - cz ),
                new THREE.Vector2( dy, 1 - dz )
            ];
        }

以下几行：

var amount = extrudeOptions.amount;
if ( Math.abs( ay - by ) < 0.01 ) {
            return [
                new THREE.Vector2( (ax - bb_minX) / bb_width, 1-(az / amount) ),
                new THREE.Vector2( (bx - bb_minX) / bb_width, 1-(bz  / amount) ),
                new THREE.Vector2( (cx - bb_minX) / bb_width, 1-(cz  / amount) ),
                new THREE.Vector2( (dx - bb_minX) / bb_width, 1- (dz  / amount) )
            ];
        } else {
            return [
                new THREE.Vector2( (ay - bb_minY) / bb_height, 1-(az / amount )),
                new THREE.Vector2( (by - bb_minY) / bb_height, 1-(bz / amount )),
                new THREE.Vector2( (cy - bb_minY) / bb_height, 1-(cz / amount )),
                new THREE.Vector2( (dy - bb_minY) / bb_height, 1-(dz / amount ))
            ];
        }`

Answer 2

仅供进一步参考。@Westlangley的答案让我找到了正确的方向，在形状上获得纹理。关键是将值从一个范围缩放到另一个范围，从世界坐标到形状内部UV范围，该范围必须为0-1。

所以我复制了三个。挤压几何。WorldUVGenerator并将其重命名为THREE。挤压几何。BoundingBoxUVGenerator和替换在成员函数GenerateTopUV（）这些行：

        return [
            new THREE.Vector2( ax, ay ),
            new THREE.Vector2( bx, by ),
            new THREE.Vector2( cx, cy )
        ];

有了这些：

    var bb = extrudedShape.getBoundingBox();
    var bb_minX = bb.minX;
    var bb_minY = bb.minY;
    var bb_width = bb.maxX - bb_minX;
    var bb_height = bb.maxY - bb_minY;
        if (bb_width == 0) bb_width = 1;
        if (bb_height == 0) bb_height = 1;
        return [new THREE.Vector2( (ax - bb_minX) / bb_width,  (ay - bb_minY) / bb_height  ),
            new THREE.Vector2( (bx - bb_minX) / bb_width,  (by - bb_minY) / bb_height  ),
            new THREE.Vector2( (cx - bb_minX) / bb_width,  (cy - bb_minY) / bb_height  )
        ];

纹理“神奇地”出现在正确的位置！

（对于从https://github.com/mrdoob/three.js/issues/1811尝试过类似命名函数的人。它不起作用，因为范围转换是以某种奇怪的方式进行的。）

这也适用于顶点坐标确实在0-1范围内的情况，以及坐标为负的情况。如果由于某种原因宽度和高度为0，则返回0。

对于大多数可能的目的来说，这比默认的三个要有用得多。挤出计量法。世界紫外线发生器。我甚至无法想象默认生成器有什么用途，因为它只适用于坐标范围为0-1的顶点。但我对三点都不熟悉。js，可能还有一些我无法想象的原因。

Answer 3

这是由z缓冲问题引起的CanvasRenderer的已知限制。几何体有许多拉长的面，这会使情况变得更糟。使用WebGLRenderer可以正确渲染模型。

ExtrudeGeometry最初是为文本编写的，如果你看一下它生成的UV，它只是为UV使用顶点位置的x和y分量，在你的情况下，它会产生超出范围[0,1]的值...您可以选择在回调函数中提供自己的UV生成器。

确保可以首先成功地将纹理添加到立方体。

三js r.58