Add support for importing and exporting GLB version 3 files

Editor/Scripts/GLTFExportMenu.cs

@@ -509,11 +509,14 @@ private static bool Export(ExportBatch batch, bool binary, bool askForLocation)
 			{
 				var sceneName = batch.sceneName;
 				var ext = binary ? ".glb" : ".gltf";
+				bool allowExporting64BitGLB = settings.AllowExporting64BitGLB;
 				var resultFile = GLTFSceneExporter.GetFileName(path, sceneName, ext);
 				settings.SaveFolderPath = path;
+				// Prefer saving as GLB version 2 for compatibility.
+				int glbVersion = allowExporting64BitGLB ? -1 : 2; // -1 means "auto".
 
 				if (binary)
-					exporter.SaveGLB(path, sceneName);
+					exporter.SaveGLB(path, sceneName, glbVersion);
 				else
 					exporter.SaveGLTFandBin(path, sceneName);
 

Editor/Scripts/GLTFImporter.cs

@@ -195,7 +195,7 @@ public class AnimationClipImportInfo
 	        // public float endTime;
 		}
 
-#if !UNIYT_2020_2_OR_NEWER
+#if !UNITY_2020_2_OR_NEWER
 	    private class NonReorderableAttribute : Attribute {}
 #endif
 
@@ -761,7 +761,7 @@ string GetUniqueName(string desiredName)
                         foreach (var mat in materials)
                         {
 	                        if (!mat) continue;
-	                        // ensure materials that are overriden aren't shown in the hierarchy.
+	                        // ensure materials that are overridden aren't shown in the hierarchy.
 	                        var si = new SourceAssetIdentifier(mat);
 	                        if (map.TryGetValue(si, out var remappedMaterial) && remappedMaterial)
 		                        mat.hideFlags = HideFlags.HideInHierarchy | HideFlags.HideInInspector;

Runtime/Plugins/GLTFSerialization/AttributeAccessor.cs

@@ -9,7 +9,7 @@ public class AttributeAccessor
 		public NumericArray AccessorContent { get; set; }
 
 		public NativeArray<byte> bufferData { get; set; }
-		public uint Offset { get; set; }
+		public long Offset { get; set; }
 
 		public AttributeAccessor()
 		{

Runtime/Plugins/GLTFSerialization/GLBObject.cs

@@ -4,6 +4,42 @@
 
 namespace GLTF
 {
+	public enum GLBChunkFormat : uint
+	{
+		JSON = 0x4e4f534a, // ASCII string "JSON" in little-endian order.
+		BIN = 0x004e4942 // ASCII string "BIN\0" in little-endian order.
+	}
+
+	/// <summary>
+	/// Information containing parsed GLB Header
+	/// </summary>
+	public struct GLBHeader
+	{
+		public uint Version { get; set; }
+		public long FileLength { get; set; }
+
+		public long GetFileHeaderSize() => Version == 2 ? 12 : 16;
+		public long GetChunkHeaderSize() => Version == 2 ? 8 : 16;
+		public long GetAlignment() => Version == 2 ? 4 : 8;
+		public long GetAlignmentBitmask() => Version == 2 ? 3 : 7;
+
+		/// <summary>
+		/// ASCII string "glTF" in little-endian order.
+		/// </summary>
+		public static readonly uint GLTF_MAGIC_NUMBER = 0x46546C67;
+	}
+
+	/// <summary>
+	/// Information that contains parsed chunk
+	/// </summary>
+	public struct GLBChunkInfo
+	{
+		public long StartPosition;
+		public long Length;
+		public GLBChunkFormat Type;
+		public uint Encoding;
+	}
+
 	/// <summary>
 	/// Objects containing GLB data and associated parsing information
 	/// </summary>
@@ -41,22 +77,22 @@ public GLBObject(GLBObject other)
 		/// <summary>
 		/// Information on JSON chunk
 		/// </summary>
-		public ChunkInfo JsonChunkInfo { get { return _jsonChunkInfo; } internal set { _jsonChunkInfo = value; } }
+		public GLBChunkInfo JsonChunkInfo { get { return _jsonChunkInfo; } internal set { _jsonChunkInfo = value; } }
 
 		/// <summary>
 		/// Information on Binary chunk
 		/// </summary>
-		public ChunkInfo BinaryChunkInfo { get { return _binaryChunkInfo; } internal set { _binaryChunkInfo = value; } }
+		public GLBChunkInfo BinaryChunkInfo { get { return _binaryChunkInfo; } internal set { _binaryChunkInfo = value; } }
 
 		private GLBHeader _glbHeader;
-		private ChunkInfo _jsonChunkInfo;
-		private ChunkInfo _binaryChunkInfo;
+		private GLBChunkInfo _jsonChunkInfo;
+		private GLBChunkInfo _binaryChunkInfo;
 
 		internal GLBObject()
 		{
 		}
 
-		internal void SetFileLength(uint newHeaderLength)
+		internal void SetFileLength(long newHeaderLength)
 		{
 			_glbHeader.FileLength = newHeaderLength;
 		}
@@ -66,7 +102,7 @@ internal void SetJsonChunkStartPosition(long startPosition)
 			_jsonChunkInfo.StartPosition = startPosition;
 		}
 
-		internal void SetJsonChunkLength(uint jsonChunkLength)
+		internal void SetJsonChunkLength(long jsonChunkLength)
 		{
 			_jsonChunkInfo.Length = jsonChunkLength;
 		}
@@ -76,7 +112,7 @@ internal void SetBinaryChunkStartPosition(long startPosition)
 			_binaryChunkInfo.StartPosition = startPosition;
 		}
 
-		internal void SetBinaryChunkLength(uint binaryChunkLength)
+		internal void SetBinaryChunkLength(long binaryChunkLength)
 		{
 			_binaryChunkInfo.Length = binaryChunkLength;
 			if (Root.Buffers == null)

Runtime/Plugins/GLTFSerialization/GLTFHelpers.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
 using System.Text.RegularExpressions;
 using GLTF.Schema;
@@ -442,7 +442,7 @@ public static void BuildAnimationSamplers(ref Dictionary<string, List<AttributeA
 
 		/// <summary>
 		/// Merges the right root into the left root
-		/// This function combines all of the lists of objects on each glTF root together and updates the relative indicies
+		/// This function combines all of the lists of objects on each glTF root together and updates the relative indices
 		/// All properties all merged except Asset and Default, which will stay "mergeToRoot"'s value
 		/// </summary>
 		/// <param name="mergeToRoot">The node to merge into</param>
@@ -475,7 +475,7 @@ public static void MergeGLTF(GLTFRoot mergeToRoot, GLTFRoot mergeFromRoot)
 			// merge extensions
 			MergeExtensions(mergeToRoot, mergeFromRootCopy);
 
-			// merge accessors, buffers, and bufferviews
+			// merge accessors, buffers, and buffer views
 			MergeAccessorsBufferViewsAndBuffers(mergeToRoot, mergeFromRootCopy, previousGLTFSize);
 
 			// merge materials, samplers, images, and textures
@@ -522,7 +522,7 @@ private static void LoadBufferView(AttributeAccessor attributeAccessor, out Nati
 			LoadBufferView(attributeAccessor.AccessorId.Value.BufferView?.Value, attributeAccessor.Offset, attributeAccessor.bufferData, out bufferViewCache);
 		}
 
-		internal static void LoadBufferView(BufferView bufferView, uint Offset, NativeArray<byte> nativeBuffer, out NativeArray<byte> bufferViewCache)
+		internal static void LoadBufferView(BufferView bufferView, long Offset, NativeArray<byte> nativeBuffer, out NativeArray<byte> bufferViewCache)
 		{
 			// The bufferView can be null for sparse buffers with just a count.
 			// In that case, this is a buffer padded with zeros, so we can just return the nativeBuffer.
@@ -532,7 +532,7 @@ internal static void LoadBufferView(BufferView bufferView, uint Offset, NativeAr
 				return;
 			}
 
-			uint totalOffset = bufferView.ByteOffset + Offset;
+			long totalOffset = bufferView.ByteOffset + Offset;
 			bufferViewCache = nativeBuffer.GetSubArray((int)totalOffset, (int)bufferView.ByteLength);
 		}