Add a component to display the list of models from gltf-Sample-Models…

… and let you load them (KhronosGroup#420)

* Add a component to display the list of sample models and let you load them at runtime.

* Some improvements to the model list loader and adding a main scene to host it

* Fix warning suppression

* Address pr feedback.  Remove commented line.  Give a nice error if the model list json fails to download.  Also improve orbit camera so that scrolling the other list doesn't cause it to zoom.

Examples/OrbitCameraController.cs

@@ -23,9 +23,6 @@ public class OrbitCameraController : MonoBehaviour
 		float x = 0.0f;
 		float y = 0.0f;
 
-		float prevMouseX;
-		float prevMouseY;
-
 		Quaternion rotation;
 
 		// Use this for initialization
@@ -59,7 +56,19 @@ void LateUpdate()
 					rotation = Quaternion.Euler(y, x, 0);
 				}
 
-				distance = Mathf.Clamp(distance * Mathf.Exp(-Input.GetAxis("Mouse ScrollWheel") * zoomSpeed), distanceMin, distanceMax);
+				var height = Display.main.renderingHeight;
+				var width = Display.main.renderingWidth;
+
+				var mouseOverRenderArea =
+					Input.mousePosition.x >= 0 &&
+					Input.mousePosition.x <= width &&
+					Input.mousePosition.y >= 0 &&
+					Input.mousePosition.y <= height;
+
+				if (Input.GetMouseButton(0) || mouseOverRenderArea)
+				{
+					distance = Mathf.Clamp(distance * Mathf.Exp(-Input.GetAxis("Mouse ScrollWheel") * zoomSpeed), distanceMin, distanceMax);
+				}
 
 				Vector3 negDistance = new Vector3(0.0f, 0.0f, -distance);
 				Vector3 position = rotation * negDistance + target.position;

Scripts/GLTFComponent.cs

@@ -35,6 +35,7 @@ public class GLTFComponent : MonoBehaviour
 		public int MaximumLod = 300;
 		public int Timeout = 8;
 		public GLTFSceneImporter.ColliderType Collider = GLTFSceneImporter.ColliderType.None;
+		public GameObject LastLoadedScene { get; private set; } = null;
 
 		private AsyncCoroutineHelper asyncCoroutineHelper;
 
@@ -137,6 +138,8 @@ public async Task Load()
 					}
 				}
 
+				LastLoadedScene = sceneImporter.LastLoadedScene;
+
 				if (PlayAnimationOnLoad)
 				{
 					Animation[] animations = sceneImporter.LastLoadedScene.GetComponents<Animation>();

Scripts/Tests/Editor/SampleModelListInspector.cs

@@ -0,0 +1,111 @@
+using Newtonsoft.Json;
+using System.Collections.Generic;
+using System.IO;
+using System.Net.Http;
+using UnityEditor;
+using UnityEngine;
+using UnityGLTF.Loader;
+
+[CustomEditor(typeof(SampleModelList))]
+public class SampleModelListInspector : Editor
+{
+	private List<SampleModel> models = null;
+	private bool requestedModelList = false;
+	private Vector2 scroll = Vector2.zero;
+	private SampleModel currentModel = null;
+
+	public override void OnInspectorGUI()
+	{
+		EditorGUILayout.PropertyField(serializedObject.FindProperty(SampleModelList.LoaderFieldName));
+		EditorGUILayout.PropertyField(serializedObject.FindProperty(SampleModelList.PathRootFieldName));
+		EditorGUILayout.PropertyField(serializedObject.FindProperty(SampleModelList.ManifestRelativePathFieldName));
+		EditorGUILayout.PropertyField(serializedObject.FindProperty(SampleModelList.ModelRelativePathFieldName));
+		EditorGUILayout.PropertyField(serializedObject.FindProperty(SampleModelList.LoadThisFrameFieldName));
+
+		serializedObject.ApplyModifiedProperties();
+
+		if (!Application.isPlaying)
+		{
+			models = null;
+			requestedModelList = false;
+			scroll = Vector2.zero;
+		}
+		else
+		{
+			if (!requestedModelList)
+			{
+				requestedModelList = true;
+
+				DownloadSampleModelList();
+			}
+
+			EditorGUILayout.LabelField("Models:");
+
+			if (models != null)
+			{
+				scroll = EditorGUILayout.BeginScrollView(scroll);
+
+				foreach (var model in models)
+				{
+					EditorGUILayout.BeginHorizontal();
+					GUIStyle style = new GUIStyle(GUI.skin.label);
+					if (model == currentModel)
+					{
+						style.fontStyle = FontStyle.Bold;
+					}
+					GUILayout.Label(model.Name, style);
+
+					foreach (var variant in model.Variants)
+					{
+						var buttonPressed = GUILayout.Button(variant.Type);
+
+						if (buttonPressed)
+						{
+							currentModel = model;
+							LoadModel(model.Name, variant.Type, variant.FileName);
+						}
+					}
+
+					EditorGUILayout.EndHorizontal();
+				}
+
+				EditorGUILayout.EndScrollView();
+			}
+		}
+	}
+
+	private void LoadModel(string modelName, string variantType, string variantName)
+	{
+		string relativePath = $"{modelName}/{variantType}/{variantName}";
+
+		serializedObject.FindProperty(SampleModelList.ModelRelativePathFieldName).stringValue = relativePath;
+		serializedObject.FindProperty(SampleModelList.LoadThisFrameFieldName).boolValue = true;
+		serializedObject.ApplyModifiedProperties();
+	}
+
+	private async void DownloadSampleModelList()
+	{
+		var pathRoot = serializedObject.FindProperty(SampleModelList.PathRootFieldName).stringValue;
+		var manifestRelativePath = serializedObject.FindProperty(SampleModelList.ManifestRelativePathFieldName).stringValue;
+
+		var loader = new WebRequestLoader(pathRoot);
+		try
+		{
+			await loader.LoadStream(manifestRelativePath);
+		}
+		catch (HttpRequestException)
+		{
+			Debug.LogError($"Failed to download sample model list manifest from: {pathRoot}{manifestRelativePath}", serializedObject.targetObject);
+			throw;
+		}
+
+		loader.LoadedStream.Seek(0, SeekOrigin.Begin);
+
+		var streamReader = new StreamReader(loader.LoadedStream);
+
+		var reader = new JsonTextReader(streamReader);
+
+		reader.Read();
+		models = SampleModelListParser.ParseSampleModels(reader);
+	}
+}

Scripts/Tests/Editor/SampleModelListParser.cs

@@ -0,0 +1,155 @@
+using Newtonsoft.Json;
+using System;
+using System.Collections.Generic;
+
+public class SampleModelVariant
+{
+	public string Type;
+	public string FileName;
+}
+
+public class SampleModel
+{
+	public string Name;
+	public string ScreenshotPath;
+	public List<SampleModelVariant> Variants;
+}
+
+public static class SampleModelListParser
+{
+	public static List<SampleModel> ParseSampleModels(JsonReader reader)
+	{
+		var models = new List<SampleModel>();
+
+		ParseStartArray(reader, "models");
+
+		while (reader.TokenType != JsonToken.EndArray)
+		{
+			models.Add(ParseSampleModel(reader));
+		}
+
+		ParseEndArray(reader, "models");
+
+		return models;
+	}
+
+	private static SampleModel ParseSampleModel(JsonReader reader)
+	{
+		var result = new SampleModel();
+
+		ParseStartObject(reader, "model");
+
+		while (reader.TokenType != JsonToken.EndObject)
+		{
+			if (reader.TokenType != JsonToken.PropertyName)
+			{
+				throw new Exception("Failed to parse model name property");
+			}
+			var propertyName = reader.Value.ToString().ToLowerInvariant();
+			reader.Read();
+
+			switch (propertyName)
+			{
+				case "name":
+					result.Name = ParsePropertyValueAsString(reader, propertyName);
+					break;
+				case "screenshot":
+					result.ScreenshotPath = ParsePropertyValueAsString(reader, propertyName);
+					break;
+				case "variants":
+					result.Variants = ParseVariants(reader);
+					break;
+			}
+		}
+
+		ParseEndObject(reader, "model");
+
+		return result;
+	}
+
+	private static string ParsePropertyValueAsString(JsonReader reader, string propertyName)
+	{
+		if (reader.TokenType != JsonToken.String)
+		{
+			throw new Exception($"Failed to parse string value for {propertyName}");
+		}
+		var result = reader.Value.ToString();
+
+		reader.Read();
+
+		return result;
+	}
+
+	private static List<SampleModelVariant> ParseVariants(JsonReader reader)
+	{
+		var variants = new List<SampleModelVariant>();
+
+		ParseStartObject(reader, "variants");
+
+		while (reader.TokenType != JsonToken.EndObject)
+		{
+			variants.Add(ParseVariant(reader));
+		}
+
+		ParseEndObject(reader, "variants");
+
+		return variants;
+	}
+
+	private static SampleModelVariant ParseVariant(JsonReader reader)
+	{
+		var result = new SampleModelVariant();
+
+		if (reader.TokenType != JsonToken.PropertyName)
+		{
+			throw new Exception("Failed to parse model variant name");
+		}
+		result.Type = reader.Value.ToString();
+		reader.Read();
+
+		if (reader.TokenType != JsonToken.String)
+		{
+			throw new Exception("Failed to parse model variant filename");
+		}
+		result.FileName = reader.Value.ToString();
+		reader.Read();
+
+		return result;
+	}
+
+	private static void ParseStartObject(JsonReader reader, string objectName)
+	{
+		if (reader.TokenType != JsonToken.StartObject)
+		{
+			throw new Exception($"Failed to parse {objectName} start");
+		}
+		reader.Read();
+	}
+
+	private static void ParseEndObject(JsonReader reader, string objectName)
+	{
+		if (reader.TokenType != JsonToken.EndObject)
+		{
+			throw new Exception($"Failed to parse {objectName} end");
+		}
+		reader.Read();
+	}
+
+	private static void ParseStartArray(JsonReader reader, string objectName)
+	{
+		if (reader.TokenType != JsonToken.StartArray)
+		{
+			throw new Exception($"Failed to parse {objectName} start");
+		}
+		reader.Read();
+	}
+
+	private static void ParseEndArray(JsonReader reader, string objectName)
+	{
+		if (reader.TokenType != JsonToken.EndArray)
+		{
+			throw new Exception($"Failed to parse {objectName} end");
+		}
+		reader.Read();
+	}
+}

Scripts/Tests/SampleModelList.cs

@@ -0,0 +1,45 @@
+using UnityEngine;
+using UnityGLTF;
+
+public class SampleModelList : MonoBehaviour
+{
+	public static string LoaderFieldName => nameof(loader);
+	public static string PathRootFieldName => nameof(pathRoot);
+	public static string ManifestRelativePathFieldName => nameof(manifestRelativePath);
+	public static string ModelRelativePathFieldName => nameof(modelRelativePath);
+	public static string LoadThisFrameFieldName => nameof(loadThisFrame);
+
+	[SerializeField]
+	private GLTFComponent loader = null;
+
+	[SerializeField]
+	private string pathRoot = "http://localhost:8080/glTF-Sample-Models/2.0/";
+
+// Disable "unused private field" because it is accessed by SampleModelListInspector using serialization.
+#pragma warning disable 414
+	[SerializeField]
+	private string manifestRelativePath = "model-index.json";
+#pragma warning restore 414
+
+	[SerializeField]
+	private string modelRelativePath = null;
+
+	[SerializeField]
+	private bool loadThisFrame = false;
+
+	private async void Update()
+	{
+		if (loadThisFrame)
+		{
+			loadThisFrame = false;
+
+			var path = pathRoot + modelRelativePath;
+			if (loader.LastLoadedScene != null)
+			{
+				Destroy(loader.LastLoadedScene);
+			}
+			loader.GLTFUri = path;
+			await loader.Load();
+		}
+	}
+}