[USDU-275] Adds testcase for checking if export keeps the original data structure

Author: lee-aandrew

package/com.unity.formats.usd/Tests/Common/CustomAsserts/ExportAssert.cs

@@ -0,0 +1,34 @@
+using UnityEngine;
+using NUnit.Framework;
+
+namespace Unity.Formats.USD.Tests
+{
+    public static class ExportAssert
+    {
+        public static class Runtime
+        {
+            public static void IsDataStructureKeptInUsdz(GameObject importedObject, string expectedObjectName, string expectedRootPrimName, string expectedMaterialsName)
+            {
+                Assert.AreEqual(importedObject.name, expectedObjectName);
+
+                var rootPrim = importedObject.transform.Find(expectedRootPrimName);
+                var materials = importedObject.transform.Find(expectedMaterialsName);
+
+                Assert.IsNotNull(rootPrim, string.Format("Root Prim was not found under expected name '{0}'", expectedRootPrimName));
+                Assert.IsNotNull(materials, string.Format("Materials was not found under expected name '{0}'", expectedMaterialsName));
+
+                Assert.IsNotNull(rootPrim.GetComponent<UsdPrimSource>(), "Root Prim GameObject did not contain UsdPrimSource component");
+                Assert.IsNotNull(materials.GetComponent<UsdPrimSource>(), "Materials GameObject did not contain UsdPrimSource component");
+
+                var materialsData = materials.transform.Find(expectedObjectName);
+                var rootPrimData = rootPrim.transform.Find(expectedObjectName);
+
+                Assert.IsNotNull(rootPrimData, string.Format("Root Prim Data was not found under expected name '{0}'", expectedObjectName));
+                Assert.IsNotNull(materialsData, string.Format("Materials Data was not found under expected name '{0}'", expectedObjectName));
+
+                Assert.IsNotNull(rootPrimData.GetComponent<UsdPrimSource>(), "Root Prim Data GameObject did not contain UsdPrimSource component");
+                Assert.IsNotNull(materialsData.GetComponent<UsdPrimSource>(), "Materials Data GameObject did not contain UsdPrimSource component");
+            }
+        }
+    }
+}

package/com.unity.formats.usd/Tests/Common/CustomAsserts/ExportAssert.cs.meta

@@ -110,5 +110,42 @@ public void ExportGameObjects_SceneClosedAfterExport()
             ExportHelpers.ExportGameObjects(new[] { new GameObject("test") }, scene, BasisTransformation.SlowAndSafe);
             Assert.IsNull(scene.Stage);
         }
+
+        [Ignore("[USDU-275] | [USDU-279]")]
+        [Test]
+        public void ExportAsUsdz_DataStructureKept()
+        {
+            var scene = ImportHelpers.InitForOpen(GetTestAssetPath(TestAssetData.FileName.TexturedOpaque));
+            var importedUsdObject = ImportHelpers.ImportSceneAsGameObject(scene, importOptions:
+                new SceneImportOptions()
+                {
+                    materialImportMode = MaterialImportMode.ImportPreviewSurface
+                }
+            );
+
+            var usdzPath = GetUSDScenePath(importedUsdObject.name + ".usdz");
+            UsdzExporter.ExportUsdz(usdzPath, importedUsdObject);
+
+            var usdObjectRootPath = importedUsdObject.GetComponent<UsdAsset>().m_usdRootPath;
+
+            Assert.AreEqual(usdObjectRootPath, "/");
+
+            var usdzScene = ImportHelpers.InitForOpen(usdzPath);
+            var usdzObject = ImportHelpers.ImportSceneAsGameObject(usdzScene, importOptions:
+                new SceneImportOptions()
+                {
+                    materialImportMode = MaterialImportMode.ImportPreviewSurface
+                }
+            );
+
+            Assert.AreEqual(usdzObject.GetComponent<UsdAsset>().m_usdRootPath, usdObjectRootPath);
+
+            ExportAssert.Runtime.IsDataStructureKeptInUsdz(
+                usdzObject,
+                expectedMaterialsName: TestAssetData.ImportGameObjectName.Material,
+                expectedRootPrimName: TestAssetData.ImportGameObjectName.RootPrim,
+                expectedObjectName: TestAssetData.FileName.TexturedOpaque
+            );
+        }
     }
 }