Handle properly shared logical volumes

Previous to this commit, logical volumes reused between different scenes of the produced files were problematic.
All their usages were basically appearing in both scenes, even the ones where the associated logical volume was hidden.

This commit cleans up the generated scene again for these cases.

phoenixExport.js

@@ -44,7 +44,7 @@ function filterArrayInPlace(a, condition, thisArg) {
  */
 function cleanup_geometry(node, hidden_paths, max_level=999, level = 0) {
     if (node.fVolume.fNodes) {
-        // drop hidden nodes, and everything after level 4
+        // drop hidden nodes, and everything after level max_level
         filterArrayInPlace(node.fVolume.fNodes.arr, n=>level<max_level&&!matches(n.fName, hidden_paths));
         // recurse to children
         for (const snode of node.fVolume.fNodes.arr) {
@@ -186,6 +186,16 @@ function set_visible_recursively(node) {
         }
     }
 }
+// makes given node and all its children recursively invisible
+function set_invisible_recursively(node) {
+    setInvisible(node);
+    if (node.fVolume.fNodes) {
+        for (var j = 0; j < node.fVolume.fNodes.arr.length; j++) {
+            var snode = node.fVolume.fNodes.arr[j];
+            set_invisible_recursively(snode);
+        }
+    }
+}
 
 /**
  * make only the given paths visible in a geometry and returns
@@ -201,8 +211,7 @@ function keep_only_subpart(volume, paths) {
             set_visible_recursively(snode);
             anyfound=true;
         } else {
-            setInvisible(snode);
-            // only hide if no subpart is shown
+            // make daughers visible if a subpart is shown
             var subpartfound = keep_only_subpart(snode.fVolume, paths);
             if (subpartfound) {
                 setVisibleDaughter(snode);
@@ -213,6 +222,22 @@ function keep_only_subpart(volume, paths) {
     return anyfound;
 }
 
+/**
+ * Removes children nodes that are not matching paths
+ * these should never have been created, but jsRoot has limitations and may create
+ * unwanted children in cases where the smae logical volume is shared by several physical
+ * volumes out of which some should be visible and others not.
+ * Root is never checking the flags of the physical volumes, only of the logical one,
+ * creating this situation
+ */
+function cleanupChildren(child, paths) {
+    // check all children and call ourselves recursively when we keep one
+    filterArrayInPlace(child.children, n=>n.name==''||matches(n.name, paths));
+    for (var n = 0; n < child.children.length; n++) {
+        cleanupChildren(child.children[n], paths);
+    }
+}
+
 /**
  * Convert a given geometry to the gltf file
  * @parameter obj the input geometry
@@ -236,24 +261,29 @@ async function internal_convert_geometry(obj, filename, max_level, subparts, hid
     // for each geometry subpart, duplicate the geometry and keep only the subpart
     body.innerHTML += "<h2>Generating all scenes (one per subpart)</h2>"
     await forceDisplay()
+
     for (const [name, entry] of Object.entries(subparts)) {
         body.innerHTML += "  " + name + "</br>"
         await forceDisplay()
         // drop nodes we do not want to see at all (usually too detailed parts)
         cleanup_geometry(obj.fNodes.arr[0], hide_children, max_level);
         // dump to gltf, using one scene per subpart
-        // set nb of degrees per face for circles approximation (default 6)
-        // here 15 means circles are polygones with 24 faces (default 60)
+        // set nb of degrees per face for circles approximation to nFaces
         geo.geoCfg('GradPerSegm', 360/nFaces);
         const paths = entry[0];
         const visibility = entry[1];
         // extract subpart of ROOT geometry
+        // first reset visibility to be sure eveything is invisible
+        set_invisible_recursively(obj.fNodes.arr[0])
+        // make top node visible
         setVisible(obj.fNodes.arr[0]);
         keep_only_subpart(obj.fMasterVolume, paths);
         // convert to gltf
         var scene = new THREE.Scene();
         scene.name = name;
         var children = geo.build(obj, {dflt_colors: true, vislevel:10, numfaces: 10000000, numnodes: 500000});
+        // remove from children paths that should not be there
+        cleanupChildren(children, paths)
         scene.children.push( children );
         if (typeof visibility == "boolean") {
             scene.userData = {"visible" : visibility};