Added service to set camera's follow offset

src/gui/plugins/scene3d/Scene3D.cc

@@ -244,12 +244,15 @@ inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
  /// \brief Wait for follow target
  public: bool followTargetWait = false;
 
- /// \brief Offset of camera from taget being followed
+ /// \brief Offset of camera from target being followed
  public: math::Vector3d followOffset = math::Vector3d(-5, 0, 3);
 
  /// \brief Flag to indicate the follow offset needs to be updated
  public: bool followOffsetDirty = false;
 
+ /// \brief Flag to indicate the follow offset has been updated
+ public: bool newFollowOffset = true;
+
  /// \brief Follow P gain
  public: double followPGain = 0.01;
 
@@ -405,6 +408,9 @@ inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
  /// \brief Follow service
  public: std::string followService;
 
+ /// \brief Follow offset service
+ public: std::string followOffsetService;
+
  /// \brief View angle service
  public: std::string viewAngleService;
 
@@ -693,7 +699,8 @@ void IgnRenderer::Render()
  this->dataPtr->followTarget);
  if (target)
  {
- if (!followTarget || target != followTarget)
+ if (!followTarget || target != followTarget
+ || this->dataPtr->newFollowOffset)
  {
  this->dataPtr->camera->SetFollowTarget(target,
  this->dataPtr->followOffset,
@@ -703,6 +710,7 @@ void IgnRenderer::Render()
  this->dataPtr->camera->SetTrackTarget(target);
  // found target, no need to wait anymore
  this->dataPtr->followTargetWait = false;
+ this->dataPtr->newFollowOffset = false;
  }
  else if (this->dataPtr->followOffsetDirty)
  {
@@ -2000,6 +2008,9 @@ void IgnRenderer::SetFollowOffset(const math::Vector3d &_offset)
 {
  std::lock_guard<std::mutex> lock(this->dataPtr->mutex);
  this->dataPtr->followOffset = _offset;
+
+ if (!this->dataPtr->followTarget.empty())
+ this->dataPtr->newFollowOffset = true;
 }
 
 /////////////////////////////////////////////////
@@ -2663,6 +2674,13 @@ void Scene3D::LoadConfig(const tinyxml2::XMLElement *_pluginElem)
  ignmsg << "Follow service on ["
  << this->dataPtr->followService << "]" << std::endl;
 
+ // follow offset
+ this->dataPtr->followOffsetService = "/gui/follow/offset";
+ this->dataPtr->node.Advertise(this->dataPtr->followOffsetService,
+ &Scene3D::OnFollowOffset, this);
+ ignmsg << "Follow offset service on ["
+ << this->dataPtr->followOffsetService << "]" << std::endl;
+
  // view angle
  this->dataPtr->viewAngleService =
  "/gui/view_angle";
@@ -2809,6 +2827,19 @@ bool Scene3D::OnFollow(const msgs::StringMsg &_msg,
  return true;
 }
 
+/////////////////////////////////////////////////
+bool Scene3D::OnFollowOffset(const msgs::Vector3d &_msg,
+ msgs::Boolean &_res)
+{
+ auto renderWindow = this->PluginItem()->findChild<RenderWindowItem *>();
+
+ math::Vector3d offset = msgs::Convert(_msg);
+ renderWindow->SetFollowOffset(offset);
+
+ _res.set_data(true);
+ return true;
+}
+
 /////////////////////////////////////////////////
 bool Scene3D::OnViewAngle(const msgs::Vector3d &_msg,
  msgs::Boolean &_res)

src/gui/plugins/scene3d/Scene3D.hh

@@ -140,6 +140,13 @@ inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
  private: bool OnFollow(const msgs::StringMsg &_msg,
  msgs::Boolean &_res);
 
+ /// \brief Callback for a follow offset request
+ /// \param[in] _msg Request message to set the camera's follow offset.
+ /// \param[in] _res Response data
+ /// \return True if the request is received
+ private: bool OnFollowOffset(const msgs::Vector3d &_msg,
+ msgs::Boolean &_res);
+
  /// \brief Callback for a view angle request
  /// \param[in] _msg Request message to set the camera to.
  /// \param[in] _res Response data