feat: ability to export selected resources as glTF without scene

Author: hybridherbst

Editor/Scripts/GLTFExportMenu.cs

@@ -7,6 +7,7 @@
 using UnityEngine;
 using UnityEngine.SceneManagement;
 using UnityEngine.Serialization;
+using Object = UnityEngine.Object;
 
 namespace UnityGLTF
 {
@@ -31,69 +32,81 @@ public static string RetrieveTexturePath(UnityEngine.Texture texture)
 	        return path;
 	    }
 
-	    private static bool TryGetExportNameAndRootTransformsFromSelection(out string sceneName, out Transform[] rootTransforms)
+	    private static bool TryGetExportNameAndRootTransformsFromSelection(out string sceneName, out Transform[] rootTransforms, out Object[] rootResources)
 	    {
 		    if (Selection.transforms.Length > 1)
 		    {
 			    sceneName = SceneManager.GetActiveScene().name;
 			    rootTransforms = Selection.transforms;
+			    rootResources = null;
 			    return true;
 		    }
 		    if (Selection.transforms.Length == 1)
 		    {
 			    sceneName = Selection.activeGameObject.name;
 			    rootTransforms = Selection.transforms;
+			    rootResources = null;
 			    return true;
 		    }
 		    if (Selection.objects.Any() && Selection.objects.All(x => x is GameObject))
 		    {
 			    sceneName = Selection.objects.First().name;
 			    rootTransforms = Selection.objects.Select(x => (x as GameObject).transform).ToArray();
+			    rootResources = null;
+			    return true;
+		    }
+
+		    if (Selection.objects.Any() && Selection.objects.All(x => x is Material))
+		    {
+			    sceneName = "Material Library";
+			    rootTransforms = null;
+			    rootResources = Selection.objects;
 			    return true;
 		    }
 
 		    sceneName = null;
 		    rootTransforms = null;
+		    rootResources = null;
 		    return false;
 	    }
 
 	    [MenuItem(MenuPrefix + ExportGltf, true)]
 	    [MenuItem(MenuPrefixGameObject + ExportGltf, true)]
 	    private static bool ExportSelectedValidate()
 	    {
-		    return TryGetExportNameAndRootTransformsFromSelection(out _, out _);
+		    return TryGetExportNameAndRootTransformsFromSelection(out _, out _, out _);
 	    }
 
 	    [MenuItem(MenuPrefix + ExportGltf)]
 	    [MenuItem(MenuPrefixGameObject + ExportGltf, false, 33)]
 	    private static void ExportSelected()
 		{
-			if (!TryGetExportNameAndRootTransformsFromSelection(out var sceneName, out var rootTransforms))
+			if (!TryGetExportNameAndRootTransformsFromSelection(out var sceneName, out var rootTransforms, out var rootResources))
 			{
 				Debug.LogError("Can't export: selection is empty");
 				return;
 			}
 
-			Export(rootTransforms, false, sceneName);
+			Export(rootTransforms, rootResources, false, sceneName);
 		}
 
 		[MenuItem(MenuPrefix + ExportGlb, true)]
 		[MenuItem(MenuPrefixGameObject + ExportGlb, true)]
 		private static bool ExportGLBSelectedValidate()
 		{
-			return TryGetExportNameAndRootTransformsFromSelection(out _, out _);
+			return TryGetExportNameAndRootTransformsFromSelection(out _, out _, out _);
 		}
 
 		[MenuItem(MenuPrefix + ExportGlb)]
 		[MenuItem(MenuPrefixGameObject + ExportGlb, false, 34)]
 		private static void ExportGLBSelected()
 		{
-			if (!TryGetExportNameAndRootTransformsFromSelection(out var sceneName, out var rootTransforms))
+			if (!TryGetExportNameAndRootTransformsFromSelection(out var sceneName, out var rootTransforms, out var rootResources))
 			{
 				Debug.LogError("Can't export: selection is empty");
 				return;
 			}
-			Export(rootTransforms, true, sceneName);
+			Export(rootTransforms, rootResources, true, sceneName);
 		}
 
 		[MenuItem(MenuPrefix + "Export active scene as glTF")]
@@ -103,7 +116,7 @@ private static void ExportScene()
 			var gameObjects = scene.GetRootGameObjects();
 			var transforms = Array.ConvertAll(gameObjects, gameObject => gameObject.transform);
 
-			Export(transforms, false, scene.name);
+			Export(transforms, null, false, scene.name);
 		}
 
 		[MenuItem(MenuPrefix + "Export active scene as GLB")]
@@ -113,15 +126,31 @@ private static void ExportSceneGLB()
 			var gameObjects = scene.GetRootGameObjects();
 			var transforms = Array.ConvertAll(gameObjects, gameObject => gameObject.transform);
 
-			Export(transforms, true, scene.name);
+			Export(transforms, null, true, scene.name);
 		}
 
-		private static void Export(Transform[] transforms, bool binary, string sceneName)
+		private static void Export(Transform[] transforms, Object[] resources, bool binary, string sceneName)
 		{
 			var settings = GLTFSettings.GetOrCreateSettings();
 			var exportOptions = new ExportContext(settings) { TexturePathRetriever = RetrieveTexturePath };
 			var exporter = new GLTFSceneExporter(transforms, exportOptions);
 
+			if (resources != null)
+			{
+				exportOptions.AfterSceneExport += (sceneExporter, _) =>
+				{
+					foreach (var resource in resources)
+					{
+						if (resource is Material material)
+							sceneExporter.ExportMaterial(material);
+						if (resource is Texture2D texture)
+							sceneExporter.ExportTexture(texture, "unknown");
+						if (resource is Mesh mesh)
+							sceneExporter.ExportMesh(mesh);
+					}
+				};
+			}
+
 			var invokedByShortcut = Event.current?.type == EventType.KeyDown;
 			var path = settings.SaveFolderPath;
 			if (!invokedByShortcut || !Directory.Exists(path))
@@ -132,7 +161,8 @@ private static void Export(Transform[] transforms, bool binary, string sceneName
 				var ext = binary ? ".glb" : ".gltf";
 				var resultFile = GLTFSceneExporter.GetFileName(path, sceneName, ext);
 				settings.SaveFolderPath = path;
-				if(binary)
+				
+				if (binary)
 					exporter.SaveGLB(path, sceneName);
 				else
 					exporter.SaveGLTFandBin(path, sceneName);