fix: Error when animation package is not enabled (fixes #267)

ChangeLog.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased] - 
+### Fixed
+- Error when animation package is not enabled (#267)
+
 ## [4.4.4] - 2021-10-28
 ### Fixed 
 - Build compiler error about missing variable (#265)

Runtime/Scripts/Schema/Root.cs

@@ -146,14 +146,16 @@ public void GltfSerialize(StreamWriter stream) {
                 writer.AddArrayProperty("extensionsUsed", extensionsUsed);
             }
 
+#if UNITY_ANIMATION
             if (animations!=null) {
                 writer.AddArray("animations");
                 foreach( var animation in animations) {
                     animation.GltfSerialize(writer);
                 }
                 writer.CloseArray();
             }
-
+#endif
+
             if (buffers!=null) {
                 writer.AddArray("buffers");
                 foreach( var buffer in buffers) {