js/Mobilizing/renderer/3D/three/shape/3D/composite/OutlineMesh.js

import * as THREE from 'three';
import Mesh from "../../Mesh";
import Transform from "../../../scene/Transform";
import Material from "../../../scene/Material";

/**
* OutlineMesh class creates a hiddenline fashioned Mesh from any other Mesh.
*/
export default class OutlineMesh extends Mesh {
    /**
    * @param {Object} params parameters this can contains the same parameters than Mesh class
    * @param {Mesh} params.inputMesh The existing Mesh to use for generate a new edge only Mesh (geometry and material)
    */
    constructor({
        inputMesh = undefined,
    } = {}) {
        super(...arguments);

        this.inputMesh = inputMesh;

        this.material = new Material({ type: "line" });

        const edg = this.inputMesh.getNativeObject().clone();
        const faces = edg.geometry.faces;
        const vertices = edg.geometry.vertices;
        const edgGeometry = new THREE.Geometry();
        const facesIndices = ["a", "b", "c", "d"];

        faces.forEach((f) => {

            if (f instanceof THREE.Face3) {

                const v1 = vertices[f[facesIndices[0]]];
                const v2 = vertices[f[facesIndices[1]]];
                const v3 = vertices[f[facesIndices[2]]];

                const d1 = v1.distanceTo(v2);
                const d2 = v1.distanceTo(v3);
                const d3 = v3.distanceTo(v2);

                if ((d1 > d2) && (d1 > d3)) {

                    edgGeometry.vertices.push(v1);
                    edgGeometry.vertices.push(v3);
                    edgGeometry.vertices.push(v2);
                    edgGeometry.vertices.push(v3);

                }
                else if (d2 > d3) {

                    edgGeometry.vertices.push(v1);
                    edgGeometry.vertices.push(v2);
                    edgGeometry.vertices.push(v3);
                    edgGeometry.vertices.push(v2);

                }
                else {

                    edgGeometry.vertices.push(v1);
                    edgGeometry.vertices.push(v2);
                    edgGeometry.vertices.push(v3);
                    edgGeometry.vertices.push(v1);
                }
            }
        });

        this._mesh = new THREE.Line(edgGeometry, this.material._material, THREE.LinePieces);

        this.transform = undefined;
        this.transform = new Transform(this);
    }
}