Fix Ogre2 assertions during ray queries

include/ignition/rendering/RayQuery.hh

@@ -89,8 +89,23 @@ namespace ignition
                 const math::Vector2d &_coord) = 0;
 
       /// \brief Compute intersections
+      /// \param[in] _forceSceneUpdate Performance optimization hint
+      /// When true Ogre2 will update all derived transforms to their
+      /// latest to get correct results.
+      ///
+      /// When false, that step is skipped. It is only safe to
+      /// set it to false when nothing has changed since the last
+      /// update (i.e. nothing moved, no new objects created).
+      ///
+      /// Ogre will assert if built in Debug mode if this value
+      /// is set to false when it shouldn't be.
+      ///
+      /// See https://ogrecave.github.io/ogre-next/api/2.2/
+      /// _ogre20_changes.html#AssersionCachedOutOfDate
+      /// for more info
       /// \return A vector of intersection results
-      public: virtual RayQueryResult ClosestPoint() = 0;
+      public: virtual RayQueryResult ClosestPoint(
+            bool _forceSceneUpdate = true) = 0;
     };
     }
   }

include/ignition/rendering/base/BaseRayQuery.hh

@@ -60,7 +60,8 @@ namespace ignition
                 const math::Vector2d &_coord) override;
 
       // Documentation inherited
-      public: virtual RayQueryResult ClosestPoint() override;
+      public: virtual RayQueryResult ClosestPoint(
+            bool _forceSceneUpdate = true) override;
 
       /// \brief Ray origin
       protected: math::Vector3d origin;
@@ -142,7 +143,8 @@ namespace ignition
 
     //////////////////////////////////////////////////
     template <class T>
-    RayQueryResult BaseRayQuery<T>::ClosestPoint()
+    RayQueryResult BaseRayQuery<T>::ClosestPoint(
+        bool /*_forceSceneUpdate*/)  // NOLINT
     {
       // TODO(anyone): implement a generic ray query here?
       RayQueryResult result;

ogre/include/ignition/rendering/ogre/OgreRayQuery.hh

@@ -50,7 +50,8 @@ namespace ignition
                 const math::Vector2d &_coord);
 
       // Documentation inherited
-      public: virtual RayQueryResult ClosestPoint();
+      public: virtual RayQueryResult ClosestPoint(
+            bool _forceSceneUpdate = true);
 
       /// \brief Get the mesh information for the given mesh.
       /// \param[in] _mesh Mesh to get info about.

ogre/src/OgreRayQuery.cc

@@ -71,7 +71,7 @@ void OgreRayQuery::SetFromCamera(const CameraPtr &_camera,
 }
 
 //////////////////////////////////////////////////
-RayQueryResult OgreRayQuery::ClosestPoint()
+RayQueryResult OgreRayQuery::ClosestPoint(bool /*_forceSceneUpdate*/) // NOLINT
 {
   RayQueryResult result;
   OgreScenePtr ogreScene = std::dynamic_pointer_cast<OgreScene>(this->Scene());

ogre2/include/ignition/rendering/ogre2/Ogre2RayQuery.hh

@@ -49,15 +49,17 @@ namespace ignition
                 const math::Vector2d &_coord);
 
       // Documentation inherited
-      public: virtual RayQueryResult ClosestPoint();
+      public: virtual RayQueryResult ClosestPoint(
+            bool _forceSceneUpdate = true);
 
       /// \brief Get closest point by selection buffer.
       /// This is executed on the GPU.
       private: RayQueryResult ClosestPointBySelectionBuffer();
 
       /// \brief Get closest point by ray triangle intersection test.
       /// This is executed on the CPU.
-      private: RayQueryResult ClosestPointByIntersection();
+      private: RayQueryResult ClosestPointByIntersection(
+            bool _forceSceneUpdate);
 
       /// \brief Private data pointer
       private: std::unique_ptr<Ogre2RayQueryPrivate> dataPtr;

ogre2/src/Ogre2RayQuery.cc

@@ -107,17 +107,17 @@ void Ogre2RayQuery::SetFromCamera(const CameraPtr &_camera,
 }
 
 //////////////////////////////////////////////////
-RayQueryResult Ogre2RayQuery::ClosestPoint()
+RayQueryResult Ogre2RayQuery::ClosestPoint(bool _forceSceneUpdate)
 {
   RayQueryResult result;
 
   // ray query using selection buffer does not seem to work on some machines
   // using cpu based ray-triangle intersection method
   // \todo remove this line if selection buffer is working again
-  return this->ClosestPointByIntersection();
+  return this->ClosestPointByIntersection(_forceSceneUpdate);
 
 #ifdef __APPLE__
-  return this->ClosestPointByIntersection();
+  return this->ClosestPointByIntersection(_forceSceneUpdate);
 #else
   if (!this->dataPtr->camera ||
       !this->dataPtr->camera->Parent() ||
@@ -126,7 +126,7 @@ RayQueryResult Ogre2RayQuery::ClosestPoint()
     // use legacy method for backward compatibility if no camera is set or
     // camera is not attached in the scene tree or
     // this function is called from non-rendering thread
-    return this->ClosestPointByIntersection();
+    return this->ClosestPointByIntersection(_forceSceneUpdate);
   }
   else
   {
@@ -172,14 +172,19 @@ RayQueryResult Ogre2RayQuery::ClosestPointBySelectionBuffer()
 }
 
 //////////////////////////////////////////////////
-RayQueryResult Ogre2RayQuery::ClosestPointByIntersection()
+RayQueryResult Ogre2RayQuery::ClosestPointByIntersection(bool _forceSceneUpdate)
 {
   RayQueryResult result;
   Ogre2ScenePtr ogreScene =
       std::dynamic_pointer_cast<Ogre2Scene>(this->Scene());
   if (!ogreScene)
     return result;
 
+  if (_forceSceneUpdate)
+  {
+    ogreScene->OgreSceneManager()->updateSceneGraph();
+  }
+
   Ogre::Ray mouseRay(Ogre2Conversions::Convert(this->origin),
       Ogre2Conversions::Convert(this->direction));