THREE.JS

Question

我有一个小演示，我有多个平面在 1024x1024 区域内堆叠在一起。任务是均匀分割 1024x1024 动画 canvas 纹理，所以我会得到以下结果：

不是这个：

所以，我必须以某种方式传递给他们的着色器 material 我需要裁剪 canvas 纹理的哪一部分。而且我不知道该怎么做。

当前代码附在此处。

下面的答案很好，但我必须对这些平面使用 glsl，所以这个解决方案可能适用于其他任务，而不是我的。

    
var renderer, scene, camera, controls, glslMaterial, uniforms, canvas, ctx, markupTexture, t = 0.0;
  
inits();
    
function inits(){

    canvas = document.createElement("canvas")

    canvas.width = 1024 * 2;
    canvas.height = 1024 * 2;

    ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#00FFFF";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    markupTexture = new THREE.CanvasTexture(canvas);
    //markupTexture.flipX = false;
    //markupTexture.flipY = false;
    
    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.setClearColor(0x000000);
    document.body.appendChild( renderer.domElement );
    
    scene = new THREE.Scene();
    
    var light = new THREE.HemisphereLight( 0xFFFFFF, 0x080820, 2.0 );
    scene.add( light );
    
    camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 5120 );
    camera.position.set(-200, 400, 400);
    
    controls = new THREE.OrbitControls(camera, renderer.domElement);
    
    var markupGeometry = new THREE.PlaneGeometry(1024, 1024, 64, 64);
    var markupPlane = new THREE.Mesh(markupGeometry, new THREE.MeshBasicMaterial({ color: 0xFFFFFF, map: markupTexture, side: THREE.DoubleSide }));
    markupPlane.rotation.set(-Math.PI / 2, 0, 0);
    markupPlane.position.set(0, 1, 0);
    //scene.add(markupPlane);
    
    var uniforms = {
        
        markup: { type: 't', value: markupTexture }
        
    };

    glslMaterial = new THREE.ShaderMaterial({
        
        uniforms: uniforms,
        vertexShader: document.getElementById('vertexShader').textContent,
        fragmentShader: document.getElementById('fragmentShader').textContent
        //side: new THREE.DoubleSide
        
    });
    
    var geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    var plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane0";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(256, 0, -256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane1";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane2";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane3";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane4";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane5";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-256, 0, 256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane6";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane7";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane8";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane9";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -384)
    scene.add(plane);
    
    window.addEventListener( "resize", onWindowResize, false );
    
    animate();
    
}
    
function onWindowResize() {
    
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize( window.innerWidth, window.innerHeight );
      
}

    
function animate() {
    
    ctx.imageSmoothingEnabled = true;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#FFFF00";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    ctx.beginPath();
    ctx.arc(1024, 1024, 640, 0, 2 * Math.PI);
    ctx.strokeStyle = "#FF00FF";
    ctx.lineWidth = 16.0;
    ctx.stroke();
    
    ctx.beginPath();
    ctx.moveTo(1024, 1024);
    ctx.arc(1024, 1024, 640, t - Math.PI / 8, t + Math.PI / 8, false);
    ctx.lineTo(1024, 1024);
    ctx.fillStyle = "#FF00FF";
    ctx.fill();
    
    controls.update();
    requestAnimationFrame( animate );
    renderer.render( scene, camera );

    for(var i = 0; i < 10; i++){
        
        scene.getObjectByName("plane" + i).material.uniforms.markup.needsUpdate = true;
        
    }
    //glslMaterial.uniforms.markup.needsUpdate = true;
    markupTexture.needsUpdate = true;
    
    t += 0.05;

}

body { margin: 0px; }

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title></title>

    <script src="https://unpkg.com/three@0.85.0/build/three.min.js"></script>
    <script src="https://unpkg.com/three@0.85.0/examples/js/controls/OrbitControls.js"></script>

</head>
<body>

<script id="vertexShader" type="x-shader/x-vertex">

    varying vec2 vUv;

    void main() {

        vUv = uv;
        gl_Position = projectionMatrix * modelViewMatrix *  vec4(position,1.0);

    }
    
</script>
    
<script id="fragmentShader" type="x-shader/x-fragment">

    uniform sampler2D markup;

    varying vec2 vUv;

    void main() {
    
        gl_FragColor = texture2D(markup, vUv);
        
    }
    
</script>

    
</body>
</html>

Answer 1

您不需要自定义着色器。您只需要为每个平面设置纹理坐标即可。

这里有一个缩放和偏移纹理坐标的函数

function offsetUVs(geometry, offU, offV, scaleU, scaleV) {
  const off = new THREE.Vector2(offU, offV);
  const scale = new THREE.Vector2(scaleU, scaleV);
  for(const uvs of geometry.faceVertexUvs[0]) {
    for (const uv of uvs) {
      uv.multiply(scale);
      uv.add(off);
    }
  }
}

如果将比例设置为 0.25，0.25 则纹理的 16 分之一将出现在该平面上（就像纹理被分成 4x4 网格一样）

偏移量将移动纹理，其中 1 是纹理的全长，0.5 是长度的一半，0.25 是长度的四分之一

var renderer, scene, camera, controls, glslMaterial, uniforms, canvas, ctx, markupTexture, t = 0.0;
  
inits();
    
function inits(){

    canvas = document.createElement("canvas")

    canvas.width = 1024 * 2;
    canvas.height = 1024 * 2;

    ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#00FFFF";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    markupTexture = new THREE.CanvasTexture(canvas);
    //markupTexture.flipX = false;
    //markupTexture.flipY = false;
    
    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.setClearColor(0x000000);
    document.body.appendChild( renderer.domElement );
    
    scene = new THREE.Scene();
    
    var light = new THREE.HemisphereLight( 0xFFFFFF, 0x080820, 2.0 );
    scene.add( light );
    
    camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 5120 );
    camera.position.set(-200, 400, 400);
    
    controls = new THREE.OrbitControls(camera, renderer.domElement);
    
    var markupGeometry = new THREE.PlaneGeometry(1024, 1024, 64, 64);
    var markupPlane = new THREE.Mesh(markupGeometry, new THREE.MeshBasicMaterial({ color: 0xFFFFFF, map: markupTexture, side: THREE.DoubleSide }));
    markupPlane.rotation.set(-Math.PI / 2, 0, 0);
    markupPlane.position.set(0, 1, 0);
    //scene.add(markupPlane);
    

    /*glslMaterial = new THREE.ShaderMaterial({
        
        uniforms: uniforms,
        vertexShader: document.getElementById('vertexShader').textContent,
        fragmentShader: document.getElementById('fragmentShader').textContent
        //side: new THREE.DoubleSide
        
    });
    */
    const simple = new THREE.MeshBasicMaterial({ color: 0xFFFFFF, map: markupTexture, side: THREE.DoubleSide });
    
    var geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    offsetUVs(geometry, 0.5, 0.5, 0.5, 0.5);
    var plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane0";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(256, 0, -256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.75, 0.25, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane1";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.5, 0.25, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane2";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.5, 0, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane3";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.75, 0, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane4";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    offsetUVs(geometry, 0, 0, 0.5, 0.5);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane5";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-256, 0, 256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.0, 0.5, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane6";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.25, 0.5, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane7";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.25, 0.75, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane8";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.0, 0.75, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, simple);
    plane.name = "plane9";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -384)
    scene.add(plane);
    
    window.addEventListener( "resize", onWindowResize, false );
    
    animate();
    
}

function offsetUVs(geometry, offU, offV, scaleU, scaleV) {
  const off = new THREE.Vector2(offU, offV);
  const scale = new THREE.Vector2(scaleU, scaleV);
  for(const uvs of geometry.faceVertexUvs[0]) {
    for (const uv of uvs) {
      uv.multiply(scale);
      uv.add(off);
    }
  }
}
    
function onWindowResize() {
    
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize( window.innerWidth, window.innerHeight );
      
}

    
function animate() {
    
    ctx.imageSmoothingEnabled = true;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#FFFF00";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    ctx.beginPath();
    ctx.arc(1024, 1024, 940, 0, 2 * Math.PI);
    ctx.strokeStyle = "#FF00FF";
    ctx.lineWidth = 16.0;
    ctx.stroke();
    
    ctx.beginPath();
    ctx.moveTo(1024, 1024);
    ctx.arc(1024, 1024, 940, t - Math.PI / 8, t + Math.PI / 8, false);
    ctx.lineTo(1024, 1024);
    ctx.fillStyle = "#FF00FF";
    ctx.fill();
    markupTexture.needsUpdate = true;
    
    controls.update();
    requestAnimationFrame( animate );
    renderer.render( scene, camera );
    
    t += 0.05;

}

body { margin: 0px; }

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title></title>

    <script src="https://unpkg.com/three@0.85.0/build/three.min.js"></script>
    <script src="https://unpkg.com/three@0.85.0/examples/js/controls/OrbitControls.js"></script>

</head>
<body>
    
</body>
</html>

Ps: 我把圆圈变大了，所以它碰到了所有的平面，否则 2 个角是纯黄色的，所以很难看出它们是否正确。

参见this article作为几何结构的参考

同样的解决方案也适用于您的自定义着色器

var renderer, scene, camera, controls, glslMaterial, uniforms, canvas, ctx, markupTexture, t = 0.0;
  
inits();
    
function inits(){

    canvas = document.createElement("canvas")

    canvas.width = 1024 * 2;
    canvas.height = 1024 * 2;

    ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#00FFFF";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    markupTexture = new THREE.CanvasTexture(canvas);
    //markupTexture.flipX = false;
    //markupTexture.flipY = false;
    
    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.setClearColor(0x000000);
    document.body.appendChild( renderer.domElement );
    
    scene = new THREE.Scene();
    
    var light = new THREE.HemisphereLight( 0xFFFFFF, 0x080820, 2.0 );
    scene.add( light );
    
    camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 5120 );
    camera.position.set(-200, 400, 400);
    
    controls = new THREE.OrbitControls(camera, renderer.domElement);
    
    var markupGeometry = new THREE.PlaneGeometry(1024, 1024, 64, 64);
    var markupPlane = new THREE.Mesh(markupGeometry, new THREE.MeshBasicMaterial({ color: 0xFFFFFF, map: markupTexture, side: THREE.DoubleSide }));
    markupPlane.rotation.set(-Math.PI / 2, 0, 0);
    markupPlane.position.set(0, 1, 0);
    //scene.add(markupPlane);
    
    var uniforms = {
        
        markup: { type: 't', value: markupTexture }
        
    };

    glslMaterial = new THREE.ShaderMaterial({
        
        uniforms: uniforms,
        vertexShader: document.getElementById('vertexShader').textContent,
        fragmentShader: document.getElementById('fragmentShader').textContent
        //side: new THREE.DoubleSide
        
    });
    
    var geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    offsetUVs(geometry, 0.5, 0.5, 0.5, 0.5);
    var plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane0";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(256, 0, -256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.75, 0.25, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane1";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.5, 0.25, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane2";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.5, 0, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane3";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.75, 0, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane4";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    offsetUVs(geometry, 0, 0, 0.5, 0.5);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane5";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-256, 0, 256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.0, 0.5, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane6";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.25, 0.5, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane7";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.25, 0.75, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane8";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    offsetUVs(geometry, 0.0, 0.75, 0.25, 0.25);
    plane = new THREE.Mesh(geometry, glslMaterial);
    plane.name = "plane9";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -384)
    scene.add(plane);
    
    window.addEventListener( "resize", onWindowResize, false );
    
    animate();
    
}

function offsetUVs(geometry, offU, offV, scaleU, scaleV) {
  const off = new THREE.Vector2(offU, offV);
  const scale = new THREE.Vector2(scaleU, scaleV);
  for(const uvs of geometry.faceVertexUvs[0]) {
    for (const uv of uvs) {
      uv.multiply(scale);
      uv.add(off);
    }
  }
}
    
function onWindowResize() {
    
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize( window.innerWidth, window.innerHeight );
      
}

    
function animate() {
    
    ctx.imageSmoothingEnabled = true;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#FFFF00";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    ctx.beginPath();
    ctx.arc(1024, 1024, 940, 0, 2 * Math.PI);
    ctx.strokeStyle = "#FF00FF";
    ctx.lineWidth = 16.0;
    ctx.stroke();
    
    ctx.beginPath();
    ctx.moveTo(1024, 1024);
    ctx.arc(1024, 1024, 940, t - Math.PI / 8, t + Math.PI / 8, false);
    ctx.lineTo(1024, 1024);
    ctx.fillStyle = "#FF00FF";
    ctx.fill();
    markupTexture.needsUpdate = true;
    
    controls.update();
    requestAnimationFrame( animate );
    renderer.render( scene, camera );
    
    t += 0.05;

}

body { margin: 0px; }

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title></title>

    <script src="https://unpkg.com/three@0.85.0/build/three.min.js"></script>
    <script src="https://unpkg.com/three@0.85.0/examples/js/controls/OrbitControls.js"></script>
<script id="vertexShader" type="x-shader/x-vertex">

    varying vec2 vUv;

    void main() {

        vUv = uv;
        gl_Position = projectionMatrix * modelViewMatrix *  vec4(position,1.0);

    }
    
</script>
    
<script id="fragmentShader" type="x-shader/x-fragment">

    uniform sampler2D markup;

    varying vec2 vUv;

    void main() {
    
        gl_FragColor = texture2D(markup, vUv);
        
    }
    
</script>
</head>
<body>
    
</body>
</html>

您也可以在着色器中进行相同的 uv 操作，但是您需要为每个平面创建一个新的 material，这样您就可以为每个平面传入不同的偏移量和比例。

var renderer, scene, camera, controls, glslMaterial, uniforms, canvas, ctx, markupTexture, t = 0.0;
  
inits();
    
function inits(){

    canvas = document.createElement("canvas")

    canvas.width = 1024 * 2;
    canvas.height = 1024 * 2;

    ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#00FFFF";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    markupTexture = new THREE.CanvasTexture(canvas);
    //markupTexture.flipX = false;
    //markupTexture.flipY = false;
    
    renderer = new THREE.WebGLRenderer( { antialias: true } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.setClearColor(0x000000);
    document.body.appendChild( renderer.domElement );
    
    scene = new THREE.Scene();
    
    var light = new THREE.HemisphereLight( 0xFFFFFF, 0x080820, 2.0 );
    scene.add( light );
    
    camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 5120 );
    camera.position.set(-200, 400, 400);
    
    controls = new THREE.OrbitControls(camera, renderer.domElement);
    
    var markupGeometry = new THREE.PlaneGeometry(1024, 1024, 64, 64);
    var markupPlane = new THREE.Mesh(markupGeometry, new THREE.MeshBasicMaterial({ color: 0xFFFFFF, map: markupTexture, side: THREE.DoubleSide }));
    markupPlane.rotation.set(-Math.PI / 2, 0, 0);
    markupPlane.position.set(0, 1, 0);
    //scene.add(markupPlane);
    
    function createMaterial(offX, offY, scaleX, scaleY) {
      var uniforms = {
          uvOffset: { value: new THREE.Vector2(offX, offY) },
          uvScale: { value: new THREE.Vector2(scaleX, scaleY) },
          markup: { type: 't', value: markupTexture }

      };

      return new THREE.ShaderMaterial({

          uniforms: uniforms,
          vertexShader: document.getElementById('vertexShader').textContent,
          fragmentShader: document.getElementById('fragmentShader').textContent
          //side: new THREE.DoubleSide

      });
    }

    var geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    var plane = new THREE.Mesh(geometry, createMaterial(0.5, 0.5, 0.5, 0.5));
    plane.name = "plane0";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(256, 0, -256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.75, 0.25, 0.25, 0.25));
    plane.name = "plane1";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.5, 0.25, 0.25, 0.25));
    plane.name = "plane2";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.5, 0, 0.25, 0.25));
    plane.name = "plane3";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(128, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.75, 0, 0.25, 0.25));
    plane.name = "plane4";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(384, 0, 384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(512, 512, 64, 64);
    plane = new THREE.Mesh(geometry, createMaterial(0, 0, 0.5, 0.5));
    plane.name = "plane5";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-256, 0, 256)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.0, 0.5, 0.25, 0.25));
    plane.name = "plane6";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.25, 0.5, 0.25, 0.25));
    plane.name = "plane7";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -128)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.25, 0.75, 0.25, 0.25));
    plane.name = "plane8";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-128, 0, -384)
    scene.add(plane);
    
    geometry = new THREE.PlaneGeometry(256, 256, 32, 32);
    plane = new THREE.Mesh(geometry, createMaterial(0.0, 0.75, 0.25, 0.25));
    plane.name = "plane9";
    plane.rotation.set(-Math.PI / 2, 0, 0);
    plane.position.set(-384, 0, -384)
    scene.add(plane);
    
    window.addEventListener( "resize", onWindowResize, false );
    
    animate();
    
}
    
function onWindowResize() {
    
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize( window.innerWidth, window.innerHeight );
      
}

    
function animate() {
    
    ctx.imageSmoothingEnabled = true;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = "#FFFF00";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    
    ctx.beginPath();
    ctx.arc(1024, 1024, 940, 0, 2 * Math.PI);
    ctx.strokeStyle = "#FF00FF";
    ctx.lineWidth = 16.0;
    ctx.stroke();
    
    ctx.beginPath();
    ctx.moveTo(1024, 1024);
    ctx.arc(1024, 1024, 940, t - Math.PI / 8, t + Math.PI / 8, false);
    ctx.lineTo(1024, 1024);
    ctx.fillStyle = "#FF00FF";
    ctx.fill();
    
    controls.update();
    requestAnimationFrame( animate );
    renderer.render( scene, camera );

    markupTexture.needsUpdate = true;
    
    t += 0.05;

}

body { margin: 0px; }

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title></title>

    <script src="https://unpkg.com/three@0.85.0/build/three.min.js"></script>
    <script src="https://unpkg.com/three@0.85.0/examples/js/controls/OrbitControls.js"></script>

</head>
<body>

<script id="vertexShader" type="x-shader/x-vertex">

    varying vec2 vUv;

    void main() {

        vUv = uv;
        gl_Position = projectionMatrix * modelViewMatrix *  vec4(position,1.0);

    }
    
</script>
    
<script id="fragmentShader" type="x-shader/x-fragment">

    uniform sampler2D markup;
    uniform vec2 uvOffset;
    uniform vec2 uvScale;

    varying vec2 vUv;

    void main() {
    
        gl_FragColor = texture2D(markup, vUv * uvScale + uvOffset);
        
    }
</script>

    
</body>
</html>

THREE.JS | GLSL 如何将 canvas 纹理拆分为多个平面

THREE.JS | GLSL How to split canvas texture to multiple planes

glsl

textures

crop

plane