如何在three.js中创建窗口、洞或减去几何体

Question

如何在three.js中创建窗口、洞或减去几何体

4

我刚开始使用three.js，需要创建一个带有门和窗户的“房间”。这是一个简单的任务，但我只找到了过时的答案。

类似的问题在这里： - 在three.js中减去几何体 - 在three.js中是否可能切掉形状几何体的部分在我的情况下，我有一个大盒子，我想减去一个较小的盒子JSFIDDLE示例：

var material = new THREE.MeshBasicMaterial({color: 0xffff00});
var faceMaterial_Y = new THREE.MeshLambertMaterial( { color: 0x0087E6 } );
var faceMaterial = new THREE.MeshLambertMaterial( { color: 0x0087E6 } );
var geometry_Y = new THREE.BoxBufferGeometry( 1.5, 1.5, 0.99 );
var faceMaterial_Y = new THREE.MeshLambertMaterial( { color: 0xffff00 } );
var cube_Y = new THREE.Mesh( geometry_Y, faceMaterial_Y);

scene.add(cube_Y);

var geometry_A = new THREE.BoxBufferGeometry( 0.7, 0.7, 0.7 );
material = new THREE.MeshBasicMaterial( {color: 0x00ff00} );
var faceMaterial_A = new THREE.MeshLambertMaterial( { color: 0x00ff00 } );
var cubeA = new THREE.Mesh( geometry_A, material );
cubeA.position.set( 0.5, 0.5, 0 );

// HOW TO SUBTRACT cube_Y - cubeA?

//create a group and add the three cubes 
var group = new THREE.Group();
group.add( cubeA );
group.add( cube_Y );
scene.add( group );

谢谢你的帮助！

- Uncoke

你链接的答案仍然正确 - threejs 本身不提供建设性实体几何运算，这些必须使用其他库（如 ThreeCSG）完成。您可以在此线程中找到更新的想法：https://github.com/mrdoob/three.js/issues/16099 - Don McCurdy

这回答了你的问题吗？在three.js中是否可能切割形状几何体的部分？ - Mugen87

2个回答

3

https://github.com/manthrax/THREE-CSGMesh

你可以尝试使用我的 CSG 库。它比其他 Three.js CSG 解决方案更加稳健。

- manthrax

你所说的更加健壮是指什么？官方库中修复了哪些问题？ - Omiod

2

更加强大，因为它更完整地处理纹理坐标、独立材质和法线。我还修复了一些原版本中存在的错误，该版本是从 https://github.com/evanw/csg.js/ 移植而来的。 - manthrax

但是，如果您不需要纹理坐标或法线，则这并不会太重要。 - manthrax

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Rabbid76 · Accepted Answer

一种选择是使用ThreeCSG / ThreeBSP来减去几何图形。

创建ThreeBSP对象从立方体几何图形中：

var geometry_Y = new THREE.BoxBufferGeometry( 1.5, 1.5, 0.99 );
var geometry_A = new THREE.BoxBufferGeometry( 0.7, 0.7, 0.7 );
geometry_A.translate( 0.5, 0.5, 0 );

var bsp_A = new ThreeBSP(geometry_A);
var bsp_Y = new ThreeBSP(geometry_Y);

减去几何形状并创建一个网格：

var bsp_YsubA = bsp_Y.subtract(bsp_A);
var bsp_mesh = bsp_YsubA.toMesh();
bsp_mesh.material = new THREE.MeshLambertMaterial( { color: 0x00ff00 } );

scene.add( bsp_mesh );

看例子：

(function onLoad() {
  var container, camera, scene, renderer, controls;
  
  init();
  animate();

  function init() {
    container = document.getElementById('container');
    
    renderer = new THREE.WebGLRenderer({
      antialias: true
    });
    renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    renderer.shadowMap.enabled = true;
    container.appendChild(renderer.domElement);

    scene = new THREE.Scene();
    scene.background = new THREE.Color(0xffffff);
    
    camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 1, 10000);
    camera.position.set(3, 1, -1);
    scene.add(camera);
    window.onresize = function() {
      renderer.setSize(window.innerWidth, window.innerHeight);
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
    }
    
    var ambientLight = new THREE.AmbientLight(0x404040);
    scene.add(ambientLight);

    var directionalLight = new THREE.DirectionalLight( 0xffffff, 0.5 );
    directionalLight.position.x = 4;
    directionalLight.position.y = 1;
    directionalLight.position.z = -2;
    scene.add( directionalLight );
    
    controls = new THREE.OrbitControls(camera, renderer.domElement);
        
    addGridHelper();
    createModel();
  }

  function createModel() {

      var geometry_Y = new THREE.BoxBufferGeometry( 1.5, 1.5, 0.99 );
      var geometry_A = new THREE.BoxBufferGeometry( 0.7, 0.7, 0.7 );
      geometry_A.translate( 0.5, 0.5, 0 );
    
      var bsp_A = new ThreeBSP(geometry_A);
      var bsp_Y = new ThreeBSP(geometry_Y);
      
      var bsp_YsubA = bsp_Y.subtract(bsp_A);
      var bsp_mesh = bsp_YsubA.toMesh();
      bsp_mesh.material = new THREE.MeshLambertMaterial( { color: 0x00ff00 } );
      
      scene.add( bsp_mesh );
  }

  function addGridHelper() {

    var helper = new THREE.GridHelper(10, 10);
    helper.material.opacity = 0.25;
    helper.material.transparent = true;
    scene.add(helper);

    var axis = new THREE.AxesHelper(100);
    scene.add(axis);
  }

  function animate() {
    requestAnimationFrame(animate);
    render();
  }

  function render() {
    renderer.render(scene, camera);
  }
})();

<!--script src="https://threejs.org/build/three.js"></!--script-->
<script src="https://rawcdn.githack.com/mrdoob/three.js/r124/build/three.js"></script>
<script src="https://rawcdn.githack.com/mrdoob/three.js/r124/examples/js/controls/OrbitControls.js"></script>
<script src="https://rawgit.com/Wilt/ThreeCSG/develop/ThreeCSG.js"></script>
<div id="container"></div>

_{另请参阅

使用ThreeCSG时出现意外结果
使用threeBSP方法后，创建的球体不平滑}