您可以在three.js中使用原始WebGL纹理吗

Question

我有一个相当复杂的架构，其中我的大部分工作都是在Three.JS中完成的，但我也有一个特殊的渲染器，可以直接渲染到原始的WebGL纹理。是否可以在three.js“纹理”中使用此WebGL纹理？看起来webgl纹理类只是一个图像、视频或画布的容器，在Three.JS内部的某个地方，它会将其上传到真正的three.js纹理中。如何才能让Three.js将我的WebGL纹理渲染到网格上？

Answer 1

@Brendan的答案不再有效。

不知道它是什么时候改变的，懒得去查找，但从r102开始

const texture = new THREE.Texture();
renderer.setTexture2D(texture, 0);  // force three.js to init the texture
const texProps = renderer.properties.get(texture);
texProps.__webglTexture = glTex;

从r103开始，setTexture2D已不复存在。你可以用这个来代替

  const forceTextureInitialization = function() {
    const material = new THREE.MeshBasicMaterial();
    const geometry = new THREE.PlaneBufferGeometry();
    const scene = new THREE.Scene();
    scene.add(new THREE.Mesh(geometry, material));
    const camera = new THREE.Camera();

    return function forceTextureInitialization(texture) {
      material.map = texture;
      renderer.render(scene, camera);
    };
  }();

  const texture = new THREE.Texture();
  forceTextureInitialization(texture);  // force three.js to init the texture
  const texProps = renderer.properties.get(texture);
  texProps.__webglTexture = glTex;

​

'use strict';

/* global THREE */

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({
    canvas: canvas
  });
  
  const fov = 75;
  const aspect = 2; // the canvas default
  const near = 0.1;
  const far = 5;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 2;

  const scene = new THREE.Scene();

  const boxWidth = 1;
  const boxHeight = 1;
  const boxDepth = 1;
  const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);
  
  const forceTextureInitialization = function() {
    const material = new THREE.MeshBasicMaterial();
    const geometry = new THREE.PlaneBufferGeometry();
    const scene = new THREE.Scene();
    scene.add(new THREE.Mesh(geometry, material));
    const camera = new THREE.Camera();

    return function forceTextureInitialization(texture) {
      material.map = texture;
      renderer.render(scene, camera);
    };
  }();

  const cubes = []; // just an array we can use to rotate the cubes

  {
    const gl = renderer.getContext();
    const glTex = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, glTex);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 2, 2, 0,
        gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array([
          255, 0, 0, 255,
          0, 255, 0, 255,
          0, 0, 255, 255,
          255, 255, 0, 255,
        ]));
    gl.generateMipmap(gl.TEXTURE_2D);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
  
    const texture = new THREE.Texture();
    forceTextureInitialization(texture);
    const texProps = renderer.properties.get(texture);
    texProps.__webglTexture = glTex;
    
    const material = new THREE.MeshBasicMaterial({
      map: texture,
    });
    const cube = new THREE.Mesh(geometry, material);
    scene.add(cube);
    cubes.push(cube); // add to our list of cubes to rotate
  }

  function render(time) {
    time *= 0.001;

    cubes.forEach((cube, ndx) => {
      const speed = .2 + ndx * .1;
      const rot = time * speed;
      cube.rotation.x = rot;
      cube.rotation.y = rot;
    });

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }

  requestAnimationFrame(render);
}

main();

<canvas id="c"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/103/three.min.js"></script>

​

注意:在three.js中没有“不支持的行为”这样的东西。Three.js不能保证你今天做的任何事情明天都会奏效。Three.js breaks whatever it wants to whenever it wants to

Answer 2

这是完全不支持的行为，但您可以模仿WebGLRenderer并直接在纹理上设置__webglTexture属性。例如：

var texure = new THREE.Texture();
var rawTexture = gl.createTexture();
texture.__webglTexture = rawTexture;
texture.__webglInit = true;
// ... use texture as a normal three.js texture ...

同样，这是完全不受支持和未定义的行为，可能会在未来的three.js版本中崩溃，但如果您追求速度，可能会暂时工作。

相反，我建议如果可以的话，研究一下WebGLRenderTarget，或者提交一个特性请求来正确地启用这个特性。