added animation support for KHR_node_visibility

Author: robertdorn83

Runtime/Scripts/SceneExporter/ExporterAnimationPointer.cs

@@ -113,6 +113,36 @@ public void AddAnimationData(Object animatedObject, string propertyName, GLTFAni
 
 			switch (animatedObject)
 			{
+				case GameObject gameObject:
+					if (propertyName == "activeSelf")
+					{
+						if (!UseAnimationPointer)
+						{
+							Debug.LogWarning(null, $"GLTFExporter error: Cannot export GameObject.activeSelf animation without KHR_animation_pointer. Skipping", animatedObject);
+							return;
+						}
+						
+						var transformIndex = GetTransformIndex(gameObject.transform);
+						if (transformIndex == -1)
+						{
+							Debug.LogError(null, $"GLTFExporter error: Could not find transform for animated GameObject \"{gameObject}\". Skipping", animatedObject);
+							return;
+						}
+
+						var node = _root.Nodes[transformIndex];
+						if (node.Extensions == null || !node.Extensions.ContainsKey(KHR_node_visibility_Factory.EXTENSION_NAME))
+						{
+							var newExtension = new KHR_node_visibility();
+							newExtension.visible = true;
+							
+							node.AddExtension(KHR_node_visibility_Factory.EXTENSION_NAME, newExtension);
+							DeclareExtensionUsage(KHR_node_visibility_Factory.EXTENSION_NAME, false);
+						}
+
+						propertyName = $"extensions/{KHR_node_visibility_Factory.EXTENSION_NAME}/{nameof(KHR_node_visibility.visible)}";
+						extensionName = KHR_node_visibility_Factory.EXTENSION_NAME;
+					}
+					break;
 				case Material material:
 					// Debug.Log("material: " + material + ", propertyName: " + propertyName);
 					// mapping from known Unity property names to glTF property names

Runtime/Scripts/SceneImporter/ImporterAnimation.cs

@@ -358,6 +358,27 @@ AttributeAccessor FindSecondaryChannel(string animationPointerPath)
 							switch (rootType)
 							{
 								case "nodes":
+									var nodeExtension = pointerHierarchy.FindNext(PointerPath.PathElement.Extension);
+									if (nodeExtension != null)
+									{
+										var extensionPath = nodeExtension.ExtractPath();
+										if (extensionPath == "extensions/KHR_node_visibility/visible")
+										{
+											pointerData = new AnimationPointerData();
+											pointerData.targetNodeIds = new int[] {rootIndex.index};
+											nodeIds = pointerData.targetNodeIds;
+											pointerData.unityPropertyNames = new string[1] { "m_IsActive" };
+											pointerData.targetType = typeof(GameObject);
+											pointerData.primaryData = samplerCache.Output; 
+											pointerData.importAccessorContentConversion = (data, frame) =>
+											{
+												var v = data.primaryData.AccessorContent.AsFloats[frame];
+												return new float[] { v };
+											};
+											break;
+										}
+									}
+
 									var pointerPropertyElement = pointerHierarchy.FindNext(PointerPath.PathElement.Property);
 									if (pointerPropertyElement == null)
 										continue;