Sync out the anchor node, issue 2854 (#3398)

* Sync out anchor node to all connected clients

* Remove warning in case anchor node is nullptr

* Always sync out the anchor node to nodes

include/openspace/navigation/orbitalnavigator.h

@@ -38,6 +38,7 @@
 #include <openspace/properties/scalar/boolproperty.h>
 #include <openspace/properties/scalar/floatproperty.h>
 #include <openspace/properties/triggerproperty.h>
+#include <openspace/util/syncdata.h>
 #include <ghoul/glm.h>
 #include <glm/gtx/quaternion.hpp>
 #include <optional>
@@ -148,6 +149,9 @@ public:
      */
     glm::dvec3 pushToSurfaceOfAnchor(const glm::dvec3& cameraPosition) const;
 
+    void updateAnchor();
+    std::vector<Syncable*> syncables();
+
     /**
      * \return The Lua library that contains all Lua functions available to affect the
      *         OrbitalNavigator
@@ -244,6 +248,7 @@ private:
     WebsocketCameraStates _websocketStates;
     ScriptCameraStates _scriptStates;
 
+    SyncData<std::string> _syncedAnchorNode;
     const SceneGraphNode* _anchorNode = nullptr;
     const SceneGraphNode* _aimNode = nullptr;
 

src/engine/openspaceengine.cpp

@@ -831,6 +831,9 @@ void OpenSpaceEngine::loadAssets() {
     global::renderEngine->updateScene();
 
     global::syncEngine->addSyncables(global::timeManager->syncables());
+    global::syncEngine->addSyncables(
+        global::navigationHandler->orbitalNavigator().syncables()
+    );
     if (_scene && _scene->camera()) {
         global::syncEngine->addSyncables(_scene->camera()->syncables());
     }
@@ -1173,6 +1176,7 @@ void OpenSpaceEngine::postSynchronizationPreDraw() {
     global::luaConsole->update();
 
     if (!master) {
+        global::navigationHandler->orbitalNavigator().updateAnchor();
         _scene->camera()->invalidateCache();
     }
 
@@ -1309,7 +1313,6 @@ void OpenSpaceEngine::postDraw() {
     global::eventEngine->triggerActions();
     global::eventEngine->triggerTopics();
 
-
     global::eventEngine->postFrameCleanup();
     global::memoryManager->PersistentMemory.housekeeping();
 

src/navigation/orbitalnavigator.cpp

@@ -1109,6 +1109,7 @@ void OrbitalNavigator::setAnchorNode(const SceneGraphNode* anchorNode,
 
     const bool changedAnchor = _anchorNode != anchorNode;
     _anchorNode = anchorNode;
+    _syncedAnchorNode = anchorNode ? anchorNode->identifier() : "";
 
     // Need to reset velocities after the actual switch in anchor node,
     // since the reset behavior depends on the anchor node.
@@ -2084,6 +2085,19 @@ double OrbitalNavigator::rotationSpeedScaleFromCameraHeight(
         1.0;
 }
 
+// This should only be run on nodes and not on master
+void OrbitalNavigator::updateAnchor() {
+    ghoul_assert(!global::windowDelegate->isMaster());
+
+    if (!_syncedAnchorNode.data().empty()) {
+        setAnchorNode(_syncedAnchorNode);
+    }
+}
+
+std::vector<Syncable*> OrbitalNavigator::syncables() {
+    return { &_syncedAnchorNode };
+}
+
 scripting::LuaLibrary OrbitalNavigator::luaLibrary() {
     return {
         "orbitalnavigation",