From dc8233c1d5559e98c2d83b70c6da62a5dd1b7d9e Mon Sep 17 00:00:00 2001
From: Robert Long <robert@robertlong.me>
Date: Tue, 17 Jul 2018 13:34:12 -0700
Subject: [PATCH 1/2] Add lazy option to GLTFLoader.

---
 docs/examples/loaders/GLTFLoader.html | 28 +++++++++++++++++++++++++++
 examples/js/loaders/GLTFLoader.js     | 16 +++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/docs/examples/loaders/GLTFLoader.html b/docs/examples/loaders/GLTFLoader.html
index dbb7988bf2b57d..f85d115fd48743 100644
--- a/docs/examples/loaders/GLTFLoader.html
+++ b/docs/examples/loaders/GLTFLoader.html
@@ -156,6 +156,34 @@ <h3>[method:null setDRACOLoader]( [param:DRACOLoader dracoLoader] )</h3>
 		Refer to this [link:https://github.com/mrdoob/three.js/tree/dev/examples/js/libs/draco#readme readme] for the details of Draco and its decoder.
 		</p>
 
+		<h3>[method:null setLazy]( [param:Boolean value] )</h3>
+		<p>
+		[page:String value] — When true, [page:Function parse] and [page:Function load] will return an object with the <em>parser</em> property set.
+		</p>
+		<p>
+			When lazy loading is enabled and the provided url points to a <em>.gltf</em> file [page:Function load] will only download the <em>.gltf</em> file. [page:Function parse] and [page:Function load] will not call <em>parser.parse()</em> or <em>parser.getDependency()</em>. Examples:
+		</p>
+		<code>
+		var loader = new THREE.GLTFLoader();
+
+		loader.setLazy(true);
+
+		loader.load('foo.gltf', function ( gltf ) {
+
+			var parser = gltf.parser;
+
+			// Modify the glTF before calling parse
+			parser.json.node[ 3 ].extensions = { EXT_foo: { bufferView: 3 } };
+
+			// Load part of the gltf 
+			parser.getDependency( "bufferView", 1 ).then( createNavMesh );
+
+			// Load the entire glTF
+			parser.parse( function ( scene, scenes, cameras, animations, json ) { } );
+
+		} );
+		</code>
+
 		<h3>[method:null parse]( [param:ArrayBuffer data], [param:String path], [param:Function onLoad], [param:Function onError] )</h3>
 		<p>
 		[page:ArrayBuffer data] — glTF asset to parse, as an ArrayBuffer or <em>JSON</em> string.<br />
diff --git a/examples/js/loaders/GLTFLoader.js b/examples/js/loaders/GLTFLoader.js
index 8946d295adebc2..9175cd47696f2e 100644
--- a/examples/js/loaders/GLTFLoader.js
+++ b/examples/js/loaders/GLTFLoader.js
@@ -12,6 +12,7 @@ THREE.GLTFLoader = ( function () {
 
 		this.manager = ( manager !== undefined ) ? manager : THREE.DefaultLoadingManager;
 		this.dracoLoader = null;
+		this.lazy = false;
 
 	}
 
@@ -76,6 +77,13 @@ THREE.GLTFLoader = ( function () {
 
 		},
 
+		setLazy: function ( lazy ) {
+
+			this.lazy = lazy;
+			return this;
+
+		},
+
 		parse: function ( data, path, onLoad, onError ) {
 
 			var content;
@@ -172,6 +180,14 @@ THREE.GLTFLoader = ( function () {
 
 			} );
 
+			if ( this.lazy ) {
+
+				onLoad( { parser: parser } );
+
+				return;
+
+			}
+
 			parser.parse( function ( scene, scenes, cameras, animations, json ) {
 
 				var glTF = {

From 77afa8cb776225332fcf24980b9fcc973387cb8f Mon Sep 17 00:00:00 2001
From: Robert Long <robert@robertlong.me>
Date: Wed, 25 Jul 2018 11:25:24 -0700
Subject: [PATCH 2/2] Call markDefs when using lazy flag.

---
 examples/js/loaders/GLTFLoader.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/examples/js/loaders/GLTFLoader.js b/examples/js/loaders/GLTFLoader.js
index 9175cd47696f2e..6e279560ae0d7e 100644
--- a/examples/js/loaders/GLTFLoader.js
+++ b/examples/js/loaders/GLTFLoader.js
@@ -182,6 +182,9 @@ THREE.GLTFLoader = ( function () {
 
 			if ( this.lazy ) {
 
+				// Mark the special nodes/meshes in json for efficient parse
+				this.markDefs();
+
 				onLoad( { parser: parser } );
 
 				return;