Three.js

Question

我正在尝试通过 Three.js 中的一组点绘制最小二乘平面。我有一个 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得出一个几何图形，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);

我一直在尝试应用来获取几何图形。这是我想出的：

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();

但是飞机根本不显示，也没有错误提示我可能哪里出错了。

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

Answer 1

这种方法应该创建平面的网格可视化。但是，我不确定这对最小二乘拟合有多适用。

 // 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() 只是 returns -normal*constant，因此使用 Plane.projectPoint() 来确定一个中心 "close to" 可能是更好的选择任意点.

Three.js - 来自 Math.Plane 的 PlaneGeometry

Three.js - PlaneGeometry from Math.Plane

javascript

3d

linear-algebra

plane