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csfieldguide/static/js/third-party/threejs/TeapotGeometry.js

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/**
* Copyright 2010-2019 three.js Authors
* licensed under MIT licence.
* third-party-licences/threejs.txt
* This is specifically from:
* https://github.com/mrdoob/three.js/blob/master/examples/js/geometries/TeapotGeometry.js
* Copied 10/10/2019
*
* Modified for browserify support by Alasdair Smith
*/

module.exports = function( THREE ) {
    /**
    * @author Eric Haines / http://erichaines.com/
    *
    * Tessellates the famous Utah teapot database by Martin Newell into triangles.
    *
    * Parameters: size = 50, segments = 10, bottom = true, lid = true, body = true,
    *   fitLid = false, blinn = true
    *
    * size is a relative scale: I've scaled the teapot to fit vertically between -1 and 1.
    * Think of it as a "radius".
    * segments - number of line segments to subdivide each patch edge;
    *   1 is possible but gives degenerates, so two is the real minimum.
    * bottom - boolean, if true (default ) then the bottom patches are added.Some consider
    *   adding the bottom heresy, so set this to "false" to adhere to the One True Way.
    * lid - to remove the lid and look inside, set to true.
    * body - to remove the body and leave the lid, set this and "bottom" to false.
    * fitLid - the lid is a tad small in the original.This stretches it a bit so you can't
    *   see the teapot's insides through the gap.
    * blinn - Jim Blinn scaled the original data vertically by dividing by about 1.3 to look
    *   nicer.If you want to see the original teapot, similar to the real-world model, set
    *   this to false.True by default.
    *   See http://en.wikipedia.org/wiki/File:Original_Utah_Teapot.jpg for the original
    *   real-world teapot ( from http://en.wikipedia.org/wiki/Utah_teapot).
    *
    * Note that the bottom (the last four patches) is not flat - blame Frank Crow, not me.
    *
    * The teapot should normally be rendered as a double sided object, since for some
    * patches both sides can be seen, e.g., the gap around the lid and inside the spout.
    *
    * Segments 'n' determines the number of triangles output.
    *   Total triangles = 32*2*n*n - 8*n[degenerates at the top and bottom cusps are deleted]
    *
    *   size_factor   # triangles
    *       1          56
    *       2         240
    *       3         552
    *       4         992
    *
    *      10        6320
    *      20       25440
    *      30       57360
    *
    * Code converted from my ancient SPD software, http://tog.acm.org/resources/SPD/
    * Created for the Udacity course "Interactive Rendering", http://bit.ly/ericity
    * YouTube video on teapot history: https://www.youtube.com/watch?v=DxMfblPzFNc
    *
    * See https://en.wikipedia.org/wiki/Utah_teapot for the history of the teapot
    *
    */

    class TeapotGeometry extends THREE.BufferGeometry {

        constructor(size = 50, segments = 10, bottom = true, lid = true, body = true, fitLid = true, blinn = true) {

            // 32 * 4 * 4 Bezier spline patches
            const teapotPatches = [
                /*rim*/
                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 3, 16, 17, 18, 7, 19, 20, 21, 11, 22, 23, 24, 15, 25, 26, 27, 18, 28, 29, 30, 21, 31, 32, 33, 24, 34, 35, 36, 27, 37, 38, 39, 30, 40, 41, 0, 33, 42, 43, 4, 36, 44, 45, 8, 39, 46, 47, 12,
                /*body*/
                12, 13, 14, 15, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 15, 25, 26, 27, 51, 60, 61, 62, 55, 63, 64, 65, 59, 66, 67, 68, 27, 37, 38, 39, 62, 69, 70, 71, 65, 72, 73, 74, 68, 75, 76, 77, 39, 46, 47, 12, 71, 78, 79, 48, 74, 80, 81, 52, 77, 82, 83, 56, 56, 57, 58, 59, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 59, 66, 67, 68, 87, 96, 97, 98, 91, 99, 100, 101, 95, 102, 103, 104, 68, 75, 76, 77, 98, 105, 106, 107, 101, 108, 109, 110, 104, 111, 112, 113, 77, 82, 83, 56, 107, 114, 115, 84, 110, 116, 117, 88, 113, 118, 119, 92,
                /*handle*/
                120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 123, 136, 137, 120, 127, 138, 139, 124, 131, 140, 141, 128, 135, 142, 143, 132, 132, 133, 134, 135, 144, 145, 146, 147, 148, 149, 150, 151, 68, 152, 153, 154, 135, 142, 143, 132, 147, 155, 156, 144, 151, 157, 158, 148, 154, 159, 160, 68,
                /*spout*/
                161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 164, 177, 178, 161, 168, 179, 180, 165, 172, 181, 182, 169, 176, 183, 184, 173, 173, 174, 175, 176, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 176, 183, 184, 173, 188, 197, 198, 185, 192, 199, 200, 189, 196, 201, 202, 193,
                /*lid*/
                203, 203, 203, 203, 204, 205, 206, 207, 208, 208, 208, 208, 209, 210, 211, 212, 203, 203, 203, 203, 207, 213, 214, 215, 208, 208, 208, 208, 212, 216, 217, 218, 203, 203, 203, 203, 215, 219, 220, 221, 208, 208, 208, 208, 218, 222, 223, 224, 203, 203, 203, 203, 221, 225, 226, 204, 208, 208, 208, 208, 224, 227, 228, 209, 209, 210, 211, 212, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 212, 216, 217, 218, 232, 241, 242, 243, 236, 244, 245, 246, 240, 247, 248, 249, 218, 222, 223, 224, 243, 250, 251, 252, 246, 253, 254, 255, 249, 256, 257, 258, 224, 227, 228, 209, 252, 259, 260, 229, 255, 261, 262, 233, 258, 263, 264, 237,
                /*bottom*/
                265, 265, 265, 265, 266, 267, 268, 269, 270, 271, 272, 273, 92, 119, 118, 113, 265, 265, 265, 265, 269, 274, 275, 276, 273, 277, 278, 279, 113, 112, 111, 104, 265, 265, 265, 265, 276, 280, 281, 282, 279, 283, 284, 285, 104, 103, 102, 95, 265, 265, 265, 265, 282, 286, 287, 266, 285, 288, 289, 270, 95, 94, 93, 92
            ];
            const teapotVertices = [
                1.4, 0, 2.4, 1.4, - 0.784, 2.4, 0.784, - 1.4, 2.4, 0, - 1.4, 2.4, 1.3375, 0, 2.53125, 1.3375, - 0.749, 2.53125, 0.749, - 1.3375, 2.53125, 0, - 1.3375, 2.53125, 1.4375, 0, 2.53125, 1.4375, - 0.805, 2.53125, 0.805, - 1.4375, 2.53125, 0, - 1.4375, 2.53125, 1.5, 0, 2.4, 1.5, - 0.84, 2.4, 0.84, - 1.5, 2.4, 0, - 1.5, 2.4, - 0.784, - 1.4, 2.4, - 1.4, - 0.784, 2.4, - 1.4, 0, 2.4, - 0.749, - 1.3375, 2.53125, - 1.3375, - 0.749, 2.53125, - 1.3375, 0, 2.53125, - 0.805, - 1.4375, 2.53125, - 1.4375, - 0.805, 2.53125, - 1.4375, 0, 2.53125, - 0.84, - 1.5, 2.4, - 1.5, - 0.84, 2.4, - 1.5, 0, 2.4, - 1.4, 0.784, 2.4, - 0.784, 1.4, 2.4, 0, 1.4, 2.4, - 1.3375, 0.749, 2.53125, - 0.749, 1.3375, 2.53125, 0, 1.3375, 2.53125, - 1.4375, 0.805, 2.53125, - 0.805, 1.4375, 2.53125, 0, 1.4375, 2.53125, - 1.5, 0.84, 2.4, - 0.84, 1.5, 2.4, 0, 1.5, 2.4, 0.784, 1.4, 2.4, 1.4, 0.784, 2.4, 0.749, 1.3375, 2.53125, 1.3375, 0.749, 2.53125, 0.805, 1.4375, 2.53125, 1.4375, 0.805, 2.53125, 0.84, 1.5, 2.4, 1.5, 0.84, 2.4, 1.75, 0, 1.875, 1.75, - 0.98, 1.875, 0.98, - 1.75, 1.875, 0, - 1.75, 1.875, 2, 0, 1.35, 2, - 1.12, 1.35, 1.12, - 2, 1.35, 0, - 2, 1.35, 2, 0, 0.9, 2, - 1.12, 0.9, 1.12, - 2, 0.9, 0, - 2, 0.9, - 0.98, - 1.75, 1.875, - 1.75, - 0.98, 1.875, - 1.75, 0, 1.875, - 1.12, - 2, 1.35, - 2, - 1.12, 1.35, - 2, 0, 1.35, - 1.12, - 2, 0.9, - 2, - 1.12, 0.9, - 2, 0, 0.9, - 1.75, 0.98, 1.875, - 0.98, 1.75, 1.875, 0, 1.75, 1.875, - 2, 1.12, 1.35, - 1.12, 2, 1.35, 0, 2, 1.35, - 2, 1.12, 0.9, - 1.12, 2, 0.9, 0, 2, 0.9, 0.98, 1.75, 1.875, 1.75, 0.98, 1.875, 1.12, 2, 1.35, 2, 1.12, 1.35, 1.12, 2, 0.9, 2, 1.12, 0.9, 2, 0, 0.45, 2, - 1.12, 0.45, 1.12, - 2, 0.45, 0, - 2, 0.45, 1.5, 0, 0.225, 1.5, - 0.84, 0.225, 0.84, - 1.5, 0.225, 0, - 1.5, 0.225, 1.5, 0, 0.15, 1.5, - 0.84, 0.15, 0.84, - 1.5, 0.15, 0, - 1.5, 0.15, - 1.12, - 2, 0.45, - 2, - 1.12, 0.45, - 2, 0, 0.45, - 0.84, - 1.5, 0.225, - 1.5, - 0.84, 0.225, - 1.5, 0, 0.225, - 0.84, - 1.5, 0.15, - 1.5, - 0.84, 0.15, - 1.5, 0, 0.15, - 2, 1.12, 0.45, - 1.12, 2, 0.45, 0, 2, 0.45, - 1.5, 0.84, 0.225, - 0.84, 1.5, 0.225, 0, 1.5, 0.225, - 1.5, 0.84, 0.15, - 0.84, 1.5, 0.15, 0, 1.5, 0.15, 1.12, 2, 0.45, 2, 1.12, 0.45, 0.84, 1.5, 0.225, 1.5, 0.84, 0.225, 0.84, 1.5, 0.15, 1.5, 0.84, 0.15, - 1.6, 0, 2.025, - 1.6, - 0.3, 2.025, - 1.5, - 0.3, 2.25, - 1.5, 0, 2.25, - 2.3, 0, 2.025, - 2.3, - 0.3, 2.025, - 2.5, - 0.3, 2.25, - 2.5, 0, 2.25, - 2.7, 0, 2.025, - 2.7, - 0.3, 2.025, - 3, - 0.3, 2.25, - 3, 0, 2.25, - 2.7, 0, 1.8, - 2.7, - 0.3, 1.8, - 3, - 0.3, 1.8, - 3, 0, 1.8, - 1.5, 0.3, 2.25, - 1.6, 0.3, 2.025, - 2.5, 0.3, 2.25, - 2.3, 0.3, 2.025, - 3, 0.3, 2.25, - 2.7, 0.3, 2.025, - 3, 0.3, 1.8, - 2.7, 0.3, 1.8, - 2.7, 0, 1.575, - 2.7, - 0.3, 1.575, - 3, - 0.3, 1.35, - 3, 0, 1.35, - 2.5, 0, 1.125, - 2.5, - 0.3, 1.125, - 2.65, - 0.3, 0.9375, - 2.65, 0, 0.9375, - 2, - 0.3, 0.9, - 1.9, - 0.3, 0.6, - 1.9, 0, 0.6, - 3, 0.3, 1.35, - 2.7, 0.3, 1.575, - 2.65, 0.3, 0.9375, - 2.5, 0.3, 1.125, - 1.9, 0.3, 0.6, - 2, 0.3, 0.9, 1.7, 0, 1.425, 1.7, - 0.66, 1.425, 1.7, - 0.66, 0.6, 1.7, 0, 0.6, 2.6, 0, 1.425, 2.6, - 0.66, 1.425, 3.1, - 0.66, 0.825, 3.1, 0, 0.825, 2.3, 0, 2.1, 2.3, - 0.25, 2.1, 2.4, - 0.25, 2.025, 2.4, 0, 2.025, 2.7, 0, 2.4, 2.7, - 0.25, 2.4, 3.3, - 0.25, 2.4, 3.3, 0, 2.4, 1.7, 0.66, 0.6, 1.7, 0.66, 1.425, 3.1, 0.66, 0.825, 2.6, 0.66, 1.425, 2.4, 0.25, 2.025, 2.3, 0.25, 2.1, 3.3, 0.25, 2.4, 2.7, 0.25, 2.4, 2.8, 0, 2.475, 2.8, - 0.25, 2.475, 3.525, - 0.25, 2.49375, 3.525, 0, 2.49375, 2.9, 0, 2.475, 2.9, - 0.15, 2.475, 3.45, - 0.15, 2.5125, 3.45, 0, 2.5125, 2.8, 0, 2.4, 2.8, - 0.15, 2.4, 3.2, - 0.15, 2.4, 3.2, 0, 2.4, 3.525, 0.25, 2.49375, 2.8, 0.25, 2.475, 3.45, 0.15, 2.5125, 2.9, 0.15, 2.475, 3.2, 0.15, 2.4, 2.8, 0.15, 2.4, 0, 0, 3.15, 0.8, 0, 3.15, 0.8, - 0.45, 3.15, 0.45, - 0.8, 3.15, 0, - 0.8, 3.15, 0, 0, 2.85, 0.2, 0, 2.7, 0.2, - 0.112, 2.7, 0.112, - 0.2, 2.7, 0, - 0.2, 2.7, - 0.45, - 0.8, 3.15, - 0.8, - 0.45, 3.15, - 0.8, 0, 3.15, - 0.112, - 0.2, 2.7, - 0.2, - 0.112, 2.7, - 0.2, 0, 2.7, - 0.8, 0.45, 3.15, - 0.45, 0.8, 3.15, 0, 0.8, 3.15, - 0.2, 0.112, 2.7, - 0.112, 0.2, 2.7, 0, 0.2, 2.7, 0.45, 0.8, 3.15, 0.8, 0.45, 3.15, 0.112, 0.2, 2.7, 0.2, 0.112, 2.7, 0.4, 0, 2.55, 0.4, - 0.224, 2.55, 0.224, - 0.4, 2.55, 0, - 0.4, 2.55, 1.3, 0, 2.55, 1.3, - 0.728, 2.55, 0.728, - 1.3, 2.55, 0, - 1.3, 2.55, 1.3, 0, 2.4, 1.3, - 0.728, 2.4, 0.728, - 1.3, 2.4, 0, - 1.3, 2.4, - 0.224, - 0.4, 2.55, - 0.4, - 0.224, 2.55, - 0.4, 0, 2.55, - 0.728, - 1.3, 2.55, - 1.3, - 0.728, 2.55, - 1.3, 0, 2.55, - 0.728, - 1.3, 2.4, - 1.3, - 0.728, 2.4, - 1.3, 0, 2.4, - 0.4, 0.224, 2.55, - 0.224, 0.4, 2.55, 0, 0.4, 2.55, - 1.3, 0.728, 2.55, - 0.728, 1.3, 2.55, 0, 1.3, 2.55, - 1.3, 0.728, 2.4, - 0.728, 1.3, 2.4, 0, 1.3, 2.4, 0.224, 0.4, 2.55, 0.4, 0.224, 2.55, 0.728, 1.3, 2.55, 1.3, 0.728, 2.55, 0.728, 1.3, 2.4, 1.3, 0.728, 2.4, 0, 0, 0, 1.425, 0, 0, 1.425, 0.798, 0, 0.798, 1.425, 0, 0, 1.425, 0, 1.5, 0, 0.075, 1.5, 0.84, 0.075, 0.84, 1.5, 0.075, 0, 1.5, 0.075, - 0.798, 1.425, 0, - 1.425, 0.798, 0, - 1.425, 0, 0, - 0.84, 1.5, 0.075, - 1.5, 0.84, 0.075, - 1.5, 0, 0.075, - 1.425, - 0.798, 0, - 0.798, - 1.425, 0, 0, - 1.425, 0, - 1.5, - 0.84, 0.075, - 0.84, - 1.5, 0.075, 0, - 1.5, 0.075, 0.798, - 1.425, 0, 1.425, - 0.798, 0, 0.84, - 1.5, 0.075, 1.5, - 0.84, 0.075
            ];
            super(); // number of segments per patch

            segments = Math.max(2, Math.floor(segments)); // Jim Blinn scaled the teapot down in size by about 1.3 for
            // some rendering tests. He liked the new proportions that he kept
            // the data in this form. The model was distributed with these new
            // proportions and became the norm. Trivia: comparing images of the
            // real teapot and the computer model, the ratio for the bowl of the
            // real teapot is more like 1.25, but since 1.3 is the traditional
            // value given, we use it here.

            const blinnScale = 1.3; // scale the size to be the real scaling factor

            const maxHeight = 3.15 * (blinn ? 1 : blinnScale);
            const maxHeight2 = maxHeight / 2;
            const trueSize = size / maxHeight2; // Number of elements depends on what is needed. Subtract degenerate
            // triangles at tip of bottom and lid out in advance.

            let numTriangles = bottom ? (8 * segments - 4) * segments : 0;
            numTriangles += lid ? (16 * segments - 4) * segments : 0;
            numTriangles += body ? 40 * segments * segments : 0;
            const indices = new Uint32Array(numTriangles * 3);
            let numVertices = bottom ? 4 : 0;
            numVertices += lid ? 8 : 0;
            numVertices += body ? 20 : 0;
            numVertices *= (segments + 1) * (segments + 1);
            const vertices = new Float32Array(numVertices * 3);
            const normals = new Float32Array(numVertices * 3);
            const uvs = new Float32Array(numVertices * 2); // Bezier form

            const ms = new THREE.Matrix4();
            ms.set(- 1.0, 3.0, - 3.0, 1.0, 3.0, - 6.0, 3.0, 0.0, - 3.0, 3.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0);
            const g = [];
            const sp = [];
            const tp = [];
            const dsp = [];
            const dtp = []; // M * G * M matrix, sort of see
            // http://www.cs.helsinki.fi/group/goa/mallinnus/curves/surfaces.html

            const mgm = [];
            const vert = [];
            const sdir = [];
            const tdir = [];
            const norm = new THREE.Vector3();
            let tcoord;
            let sval;
            let tval;
            let p;
            let dsval = 0;
            let dtval = 0;
            const normOut = new THREE.Vector3();
            const gmx = new THREE.Matrix4();
            const tmtx = new THREE.Matrix4();
            const vsp = new THREE.Vector4();
            const vtp = new THREE.Vector4();
            const vdsp = new THREE.Vector4();
            const vdtp = new THREE.Vector4();
            const vsdir = new THREE.Vector3();
            const vtdir = new THREE.Vector3();
            const mst = ms.clone();
            mst.transpose(); // internal function: test if triangle has any matching vertices;
            // if so, don't save triangle, since it won't display anything.

            const notDegenerate = (vtx1, vtx2, vtx3) => // if any vertex matches, return false
            !(vertices[vtx1 * 3] === vertices[vtx2 * 3] && vertices[vtx1 * 3 + 1] === vertices[vtx2 * 3 + 1] && vertices[vtx1 * 3 + 2] === vertices[vtx2 * 3 + 2] || vertices[vtx1 * 3] === vertices[vtx3 * 3] && vertices[vtx1 * 3 + 1] === vertices[vtx3 * 3 + 1] && vertices[vtx1 * 3 + 2] === vertices[vtx3 * 3 + 2] || vertices[vtx2 * 3] === vertices[vtx3 * 3] && vertices[vtx2 * 3 + 1] === vertices[vtx3 * 3 + 1] && vertices[vtx2 * 3 + 2] === vertices[vtx3 * 3 + 2]);

            for (let i = 0; i < 3; i++) {

                mgm[i] = new THREE.Matrix4();

            }

            const minPatches = body ? 0 : 20;
            const maxPatches = bottom ? 32 : 28;
            const vertPerRow = segments + 1;
            let surfCount = 0;
            let vertCount = 0;
            let normCount = 0;
            let uvCount = 0;
            let indexCount = 0;

            for (let surf = minPatches; surf < maxPatches; surf++) {

                // lid is in the middle of the data, patches 20-27,
                // so ignore it for this part of the loop if the lid is not desired
                if (lid || surf < 20 || surf >= 28) {

                    // get M * G * M matrix for x,y,z
                    for (let i = 0; i < 3; i++) {

                        // get control patches
                        for (let r = 0; r < 4; r++) {

                            for (let c = 0; c < 4; c++) {

                                // transposed
                                g[c * 4 + r] = teapotVertices[teapotPatches[surf * 16 + r * 4 + c] * 3 + i]; // is the lid to be made larger, and is this a point on the lid
                                // that is X or Y?

                                if (fitLid && surf >= 20 && surf < 28 && i !== 2) {

                                    // increase XY size by 7.7%, found empirically. I don't
                                    // increase Z so that the teapot will continue to fit in the
                                    // space -1 to 1 for Y (Y is up for the final model).
                                    g[c * 4 + r] *= 1.077;

                                } // Blinn "fixed" the teapot by dividing Z by blinnScale, and that's the
                                // data we now use. The original teapot is taller. Fix it:


                                if (!blinn && i === 2) {

                                    g[c * 4 + r] *= blinnScale;

                                }

                            }

                        }

                        gmx.set(g[0], g[1], g[2], g[3], g[4], g[5], g[6], g[7], g[8], g[9], g[10], g[11], g[12], g[13], g[14], g[15]);
                        tmtx.multiplyMatrices(gmx, ms);
                        mgm[i].multiplyMatrices(mst, tmtx);

                    } // step along, get points, and output


                    for (let sstep = 0; sstep <= segments; sstep++) {

                        const s = sstep / segments;

                        for (let tstep = 0; tstep <= segments; tstep++) {

                            const t = tstep / segments; // point from basis
                            // get power vectors and their derivatives

                            for (p = 4, sval = tval = 1.0; p--;) {

                                sp[p] = sval;
                                tp[p] = tval;
                                sval *= s;
                                tval *= t;

                                if (p === 3) {

                                    dsp[p] = dtp[p] = 0.0;
                                    dsval = dtval = 1.0;

                                } else {

                                    dsp[p] = dsval * (3 - p);
                                    dtp[p] = dtval * (3 - p);
                                    dsval *= s;
                                    dtval *= t;

                                }

                            }

                            vsp.fromArray(sp);
                            vtp.fromArray(tp);
                            vdsp.fromArray(dsp);
                            vdtp.fromArray(dtp); // do for x,y,z

                            for (let i = 0; i < 3; i++) {

                                // multiply power vectors times matrix to get value
                                tcoord = vsp.clone();
                                tcoord.applyMatrix4(mgm[i]);
                                vert[i] = tcoord.dot(vtp); // get s and t tangent vectors

                                tcoord = vdsp.clone();
                                tcoord.applyMatrix4(mgm[i]);
                                sdir[i] = tcoord.dot(vtp);
                                tcoord = vsp.clone();
                                tcoord.applyMatrix4(mgm[i]);
                                tdir[i] = tcoord.dot(vdtp);

                            } // find normal


                            vsdir.fromArray(sdir);
                            vtdir.fromArray(tdir);
                            norm.crossVectors(vtdir, vsdir);
                            norm.normalize(); // if X and Z length is 0, at the cusp, so point the normal up or down, depending on patch number

                            if (vert[0] === 0 && vert[1] === 0) {

                                // if above the middle of the teapot, normal points up, else down
                                normOut.set(0, vert[2] > maxHeight2 ? 1 : - 1, 0);

                            } else {

                                // standard output: rotate on X axis
                                normOut.set(norm.x, norm.z, - norm.y);

                            } // store it all


                            vertices[vertCount++] = trueSize * vert[0];
                            vertices[vertCount++] = trueSize * (vert[2] - maxHeight2);
                            vertices[vertCount++] = - trueSize * vert[1];
                            normals[normCount++] = normOut.x;
                            normals[normCount++] = normOut.y;
                            normals[normCount++] = normOut.z;
                            uvs[uvCount++] = 1 - t;
                            uvs[uvCount++] = 1 - s;

                        }

                    } // save the faces


                    for (let sstep = 0; sstep < segments; sstep++) {

                        for (let tstep = 0; tstep < segments; tstep++) {

                            const v1 = surfCount * vertPerRow * vertPerRow + sstep * vertPerRow + tstep;
                            const v2 = v1 + 1;
                            const v3 = v2 + vertPerRow;
                            const v4 = v1 + vertPerRow; // Normals and UVs cannot be shared. Without clone(), you can see the consequences
                            // of sharing if you call geometry.applyMatrix4( matrix ).

                            if (notDegenerate(v1, v2, v3)) {

                                indices[indexCount++] = v1;
                                indices[indexCount++] = v2;
                                indices[indexCount++] = v3;

                            }

                            if (notDegenerate(v1, v3, v4)) {

                                indices[indexCount++] = v1;
                                indices[indexCount++] = v3;
                                indices[indexCount++] = v4;

                            }

                        }

                    } // increment only if a surface was used


                    surfCount++;

                }

            }

            this.setIndex(new THREE.BufferAttribute(indices, 1));
            this.setAttribute('position', new THREE.BufferAttribute(vertices, 3));
            this.setAttribute('normal', new THREE.BufferAttribute(normals, 3));
            this.setAttribute('uv', new THREE.BufferAttribute(uvs, 2));
            this.computeBoundingSphere();

        }

    }


    //   TeapotBufferGeometry.prototype = Object.create( THREE.BufferGeometry.prototype );
    //   TeapotBufferGeometry.prototype.constructor = THREE.TeapotBufferGeometry;

    return TeapotGeometry;
}