Merge pull request #18728 from Mugen87/dev43

Utils: Move converters to modules.

utils/converters/README.md

 Utilities for converting model files to the Three.js JSON format.
+It's necessary to install the [esm](https://www.npmjs.com/package/esm) npm package before you can use the converters.
 
 ## obj2three.js
 
 Usage:
 
 ```
-node obj2three.js model.obj
+node -r esm obj2three.js model.obj
 ```
 
 ## fbx2three.js
@@ -13,5 +14,5 @@ node obj2three.js model.obj
 Usage:
 
 ```
-node fbx2three.js model.fbx
+node -r esm fbx2three.js model.fbx
 ```

utils/converters/fbx2three.js

-var fs = require( 'fs' );
-var path = require( 'path' );
+import fs from 'fs';
+import path from 'path';
+
+import { FBXLoader } from '../../examples/jsm/loaders/FBXLoader.js';
+import { ImageLoader, ImageUtils, LoaderUtils } from '../../build/three.module.js';
 
 if ( process.argv.length <= 2 ) {
 
@@ -10,7 +13,7 @@ if ( process.argv.length <= 2 ) {
 
 //
 
-var PRECISION = 6;
+const PRECISION = 6;
 
 function parseNumber( key, value ) {
 
@@ -18,12 +21,6 @@ function parseNumber( key, value ) {
 
 }
 
-THREE = require( '../../build/three.js' );
-require( '../../examples/js/curves/NURBSCurve.js' );
-require( '../../examples/js/curves/NURBSUtils.js' );
-require( '../../examples/js/loaders/FBXLoader.js' );
-global.Zlib = require( '../../examples/js/libs/inflate.min.js' ).Zlib;
-
 global.window = {
 	innerWidth: 1024,
 	innerHeight: 768,
@@ -39,7 +36,7 @@ global.window = {
 };
 
 // HTML Images are not available, so use a Buffer instead.
-THREE.ImageLoader.prototype.load = function ( url, onLoad ) {
+ImageLoader.prototype.load = function ( url, onLoad ) {
 
 	if ( this.path !== undefined ) url = this.path + url;
 
@@ -56,7 +53,7 @@ THREE.ImageLoader.prototype.load = function ( url, onLoad ) {
 };
 
 // Convert image buffer to data URL.
-THREE.ImageUtils.getDataURL = function ( image ) {
+ImageUtils.getDataURL = function ( image ) {
 
 	if ( ! ( image instanceof Buffer ) ) {
 
@@ -64,7 +61,7 @@ THREE.ImageUtils.getDataURL = function ( image ) {
 
 	}
 
-	var dataURL = 'data:';
+	let dataURL = 'data:';
 	dataURL += this.format === THREE.RGBAFormat ? 'image/png' : 'image/jpeg';
 	dataURL += ';base64,';
 	dataURL += image.toString( 'base64' );
@@ -74,11 +71,11 @@ THREE.ImageUtils.getDataURL = function ( image ) {
 
 //
 
-var file = process.argv[ 2 ];
-var resourceDirectory = THREE.LoaderUtils.extractUrlBase( file );
-var loader = new THREE.FBXLoader();
+const file = process.argv[ 2 ];
+const resourceDirectory = LoaderUtils.extractUrlBase( file );
+const loader = new FBXLoader();
 
-var arraybuffer = fs.readFileSync( file ).buffer;
-var object = loader.parse( arraybuffer, resourceDirectory );
-var content = JSON.stringify( object.toJSON(), parseNumber );
+const arraybuffer = fs.readFileSync( file ).buffer;
+const object = loader.parse( arraybuffer, resourceDirectory );
+const content = JSON.stringify( object.toJSON(), parseNumber );
 fs.writeFileSync( path.basename( file, '.fbx' ) + '.json', content, 'utf8' );

utils/converters/obj2three.js

-var fs = require( 'fs' );
-var path = require( 'path' );
+import fs from 'fs';
+import path from 'path';
+
+import { OBJLoader } from '../../examples/jsm/loaders/OBJLoader.js';
 
 if ( process.argv.length <= 2 ) {
 
@@ -10,7 +12,7 @@ if ( process.argv.length <= 2 ) {
 
 //
 
-var PRECISION = 6;
+const PRECISION = 6;
 
 function parseNumber( key, value ) {
 
@@ -18,13 +20,10 @@ function parseNumber( key, value ) {
 
 }
 
-THREE = require( '../../build/three.js' );
-require( '../../examples/js/loaders/OBJLoader.js' );
-
-var file = process.argv[ 2 ];
-var loader = new THREE.OBJLoader();
+const file = process.argv[ 2 ];
+const loader = new OBJLoader();
 
-var text = fs.readFileSync( file, 'utf8' );
+const text = fs.readFileSync( file, 'utf8' );
 
-var content = JSON.stringify( loader.parse( text ).toJSON(), parseNumber );
+const content = JSON.stringify( loader.parse( text ).toJSON(), parseNumber );
 fs.writeFileSync( path.basename( file, '.obj' ) + '.json', content, 'utf8' );