diff --git a/js/scene.js b/js/scene.js
index bc1860b..86da6b2 100644
--- a/js/scene.js
+++ b/js/scene.js
@@ -282,6 +282,10 @@ Scene.loadNodes = function (nodes) {
             AppState.clipping.boundingSphere = node.getBound();
         }
 
+        if (!AppState.clipping.boundingSphere) {
+            console.error("There is no computed bounding sphere, clipping will fail. Missing main node?");
+        }
+
         AppState.nodes.push({id: n.label, active: true});
     });
 }
diff --git a/js/state.js b/js/state.js
index 6f46dae..7300779 100644
--- a/js/state.js
+++ b/js/state.js
@@ -1,6 +1,17 @@
 /**
  * @namespace AppState
  */
+
+/**
+ * @typedef {Object} NormalizedSceneNode
+ * @property {String} label Required
+ * @property {String} id
+ * @property {String} model
+ * @property {Boolean} isMain
+ * @property {Number|null} opacity
+ * @property {Boolean} active
+ */
+
 let AppState = {
     // The Leaflet map object
     map : null,
@@ -8,6 +19,9 @@ let AppState = {
     root: null,
     // {id: String, active: Boolean}
     nodes: [],
+    /**
+     * @property {NormalizedSceneNode[]} normalizedNodes
+     */
     normalizedNodes: [],
     mainNodeId: null,
     currentScene: null,
diff --git a/js/utils/nodeUtils.js b/js/utils/nodeUtils.js
index 20a19cf..2158066 100644
--- a/js/utils/nodeUtils.js
+++ b/js/utils/nodeUtils.js
@@ -1,18 +1,42 @@
 /**
- * @module
+ * @module nodeUtils
+ * Utilities to process scene nodes.
+ */
+
+/**
+ * @typedef {Object} SceneNode
+ * @property {String} label Required
+ * @property {String} model
+ * @property {Boolean} isMain
+ * @property {Number|null} opacity
+ * @property {SceneNode[]|null} children
+ */
+
+/**
+ * @typedef {Object} NormalizedSceneNode
+ * @property {String} label Required
+ * @property {String} id
+ * @property {String} model
+ * @property {Boolean} isMain
+ * @property {Number|null} opacity
+ * @property {Boolean} active
  */
 
 /**
  * 
- * @param {Object} node 
- * @param {Object[]} flatList 
+ * @param {SceneNode} node 
+ * @param {Array} flatList 
  * @param {Number} depth
  */
 function traverse(node, flatList, depth = 1) {
+    if (!node.label) {
+        console.error("Node missing label:", node);
+        return;
+    }
+
     const normNode = {
-        id: node.label,
-        label: node.label,
-        opacity: node.opacity ?? null,
+        ...node,
+        id: node.id ?? node.label,
         isMain: node.isMain ?? false,
         active: true,
     };
@@ -23,7 +47,7 @@ function traverse(node, flatList, depth = 1) {
         ...normNode,
         depth
     });
-    if (node.children) {
+    if (node.children && Array.isArray(node.children)) {
         for(let child of node.children) {
             traverse(child, flatList, depth + 1);
         }
@@ -34,7 +58,7 @@ function traverse(node, flatList, depth = 1) {
  * Create a flat list of nodes from
  * the nested structure in config
  * @param {Array} nodes
- * @returns {Object[]} A flat list of nodes
+ * @returns {NormalizedSceneNode[]} A flat list of nodes
 **/
 export function normalizeNodes (nodes) {
     let flatList = [];