如何在three.js中加载和显示SVG图形? [英] How do you load and display SVG graphics in three.js?

问题描述

考虑一下，我有一个SVG矢量图形文件(徽标)，我想将其加载并显示在three.js(使用WebGL渲染器)中.

Consider, I have an SVG vector graphics file (logotype), which I want to load and display in three.js (with WebGL renderer).

推荐使用哪种方法?

似乎我需要加载图像并从中创建几何图形和网格.

It seems like I need to load the image and to create a geometry and a mesh from it.

我已经成功地使用THREE.SVGLoader加载了SVG文档，但是我无法找到有关如何从其下边创建几何/网格的任何相关信息.

I've managed to load the SVG document using the THREE.SVGLoader, but I can't find any relevant information on how to create a geometry/mesh from it further down the line.

function preload () {

  const svgLoader = new THREE.SVGLoader();

  svgLoader.load('images/logo.svg', svgDocument => {

    // @todo: create a geometry/mesh from svgDocument?

    // @todo: scene.add(logoMesh);

  });

}

推荐答案

纹理

如果仅出于纹理目的需要svg:

Texture

If you need svg only for texture purposes:

1. 将svg图像渲染到画布上
2. 使用该画布作为纹理来源
3. 在场景中使用纹理...

免责声明我不是该代码的作者，我只是修正了 jsfiddle 我找到了

Disclaimer I'm not the author of this code, I just fixed jsfiddle that I've found

window.onload = () => {
  var mesh;
  var scene = new THREE.Scene();

  var camera = new THREE.PerspectiveCamera(50, 500 / 400, 0.1, 1000);
  camera.position.z = 10;

  var renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setSize(500, 400);
  document.body.appendChild(renderer.domElement);

  var svg = document.getElementById("svgContainer").querySelector("svg");
  var svgData = (new XMLSerializer()).serializeToString(svg);

  var canvas = document.createElement("canvas");
  var svgSize = svg.getBoundingClientRect();
  canvas.width = svgSize.width;
  canvas.height = svgSize.height;
  var ctx = canvas.getContext("2d");

  var img = document.createElement("img");
  img.setAttribute("src", "data:image/svg+xml;base64," + window.btoa(unescape(encodeURIComponent(svgData))) );

  img.onload = function() {
    ctx.drawImage(img, 0, 0);

    var texture = new THREE.Texture(canvas);
    texture.needsUpdate = true;

    var geometry = new THREE.SphereGeometry(3, 50, 50, 0, Math.PI * 2, 0, Math.PI * 2);
    var material = new THREE.MeshBasicMaterial({ map: texture });
    material.map.minFilter = THREE.LinearFilter;
    mesh = new THREE.Mesh(geometry, material);
    scene.add(mesh);
  };

  var render = function () {
      requestAnimationFrame(render);
      mesh.rotation.y += 0.01;
      renderer.render(scene, camera);
  };

  render();
}

<script src="https://threejs.org/build/three.min.js"></script>

<div id="svgContainer" style="width: 222px; height: 222px;">
  <svg width="200" height="200" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <rect width="200" height="200" fill="lime" stroke-width="4" stroke="pink" />
    <circle cx="125" cy="125" r="75" fill="orange" />
    <polyline points="50,150 50,200 200,200 200,100" stroke="red" stroke-width="4" fill="none" />
    <line x1="50" y1="50" x2="200" y2="200" stroke="blue" stroke-width="4" />
  </svg>
</div>

如果您想将svg渲染为几何图形，我会建议使用某些库，例如 svg-mesh-3d

If you would like to render svg as geometry I'll would suggest use of some libraries e.g. svg-mesh-3d

svg-mesh-3d文档的示例

Example from docs of svg-mesh-3d

    var loadSvg = require('load-svg')
    var parsePath = require('extract-svg-path').parse
    var svgMesh3d = require('svg-mesh-3d')

    loadSvg('svg/logo.svg', function (err, svg) {
      if (err) throw err

      var svgPath = parsePath(svg)
      var mesh = svgMesh3d(svgPath, {
        delaunay: false,
        scale: 4
      })
    })

搅拌器

替代方法是使用Blender导入svg，(可选)调整几何形状，并使用 查看全文