Add existing to tracked

node_modules/@cesium/engine/Source/Scene/VoxelMetadataOrder.js

@@ -0,0 +1,29 @@
+// @ts-check
+
+/**
+ * Metadata ordering for voxel content.
+ * In all cases, x data is contiguous in strides along the y axis,
+ * and each group of y strides represents a z slice.
+ * However, the orientation of the axes follows different conventions.
+ *
+ * @enum {number}
+ * @private
+ */
+const VoxelMetadataOrder = {
+  /**
+   * The default ordering following the 3D Tiles convention. Z-axis points upward.
+   * @type {number}
+   * @constant
+   */
+  Z_UP: 0,
+  /**
+   * The ordering following the glTF convention. Y-axis points upward.
+   * @type {number}
+   * @constant
+   */
+  Y_UP: 1,
+};
+
+Object.freeze(VoxelMetadataOrder);
+
+export default VoxelMetadataOrder;