Question

我试图通过Three.js中的一组点绘制最小二乘平面。我的plane定义如下：

var plane = new THREE.Plane();
plane.setFromNormalAndCoplanarPoint(normal, point).normalize();

我的理解是，我需要使用该平面并使用它来提出几何图形，以便创建一个网格以添加到场景中进行显示：

var dispPlane = new THREE.Mesh(planeGeometry, planeMaterial);
scene.add(dispPlane);

我一直在尝试应用this answer来获取几何体。这就是我想出的：

plane.setFromNormalAndCoplanarPoint(dir, centroid).normalize();
planeGeometry.vertices.push(plane.normal);
planeGeometry.vertices.push(plane.orthoPoint(plane.normal));
planeGeometry.vertices.push(plane.orthoPoint(planeGeometry.vertices[1]));
planeGeometry.faces.push(new THREE.Face3(0, 1, 2));

planeGeometry.computeFaceNormals();
planeGeometry.computeVertexNormals();

但是飞机根本没有显示，并且没有错误表明我可能出错的地方。

所以我的问题是，我如何获取我的Math.Plane对象并将其用作网格的几何？

Answer 1

此方法应创建平面的网格可视化。我不确定这对最小二乘拟合的适用程度如何。

 // Create plane
var dir = new THREE.Vector3(0,1,0);
var centroid = new THREE.Vector3(0,200,0);
var plane = new THREE.Plane();
plane.setFromNormalAndCoplanarPoint(dir, centroid).normalize();

// Create a basic rectangle geometry
var planeGeometry = new THREE.PlaneGeometry(100, 100);

// Align the geometry to the plane
var coplanarPoint = plane.coplanarPoint();
var focalPoint = new THREE.Vector3().copy(coplanarPoint).add(plane.normal);
planeGeometry.lookAt(focalPoint);
planeGeometry.translate(coplanarPoint.x, coplanarPoint.y, coplanarPoint.z);

// Create mesh with the geometry
var planeMaterial = new THREE.MeshLambertMaterial({color: 0xffff00, side: THREE.DoubleSide});
var dispPlane = new THREE.Mesh(planeGeometry, planeMaterial);
scene.add(dispPlane);

Answer 2

var material = ...;
var plane = new THREE.Plane(...);

// Align to plane
var geometry = new THREE.PlaneGeometry(100, 100);
var mesh = new THREE.Mesh(geometry, material);
mesh.translate(plane.coplanarPoint());
mesh.quaternion.setFromUnitVectors(new THREE.Vector3(0,0,1), plane.normal);

请注意，Plane.coplanarPoint()只返回-normal*constant，因此使用Plane.projectPoint()确定“接近”任意点的中心可能是更好的选择。

Three.js - Math.Plane中的PlaneGeometry

2 个答案: