Added additional pose offset for the performer detector

Changelog.md

@@ -6,6 +6,9 @@
  JointStatePublisher.
  * [Pull Request 222](https:/ignitionrobotics/ign-gazebo/pull/222)
 
+1. Added an additional pose offset for the performer detector plugin.
+ * [Pull Request 235](https:/ignitionrobotics/ign-gazebo/pull/235)
+
 ### Ignition Gazebo 2.20.1 (2020-06-18)
 
 1. Properly add new models into the scenegraph. With this fix, when a model is spawned it will be added into the graph and resulting calls to the `scene/info` service will return a correct `msgs::Scene`.

src/systems/performer_detector/PerformerDetector.cc

@@ -77,6 +77,11 @@ void PerformerDetector::Configure(const Entity &_entity,
  return;
  }
 
+ if (sdfClone->HasElement("pose"))
+ {
+ this->poseOffset = sdfClone->Get<math::Pose3d>("pose");
+ }
+
  std::string defaultTopic{"/model/" + this->model.Name(_ecm) +
  "/performer_detector/status"};
  auto topic = _sdf->Get<std::string>("topic", defaultTopic).first;
@@ -109,7 +114,8 @@ void PerformerDetector::PostUpdate(
 
  // Double negative because AxisAlignedBox does not currently have operator+
  // that takes a position
- auto region = this->detectorGeometry - (-modelPose.Pos());
+ auto region = this->detectorGeometry -
+ (-(modelPose.Pos() + this->poseOffset.Pos()));
 
  _ecm.Each<components::Performer, components::Geometry,
  components::ParentEntity>(

src/systems/performer_detector/PerformerDetector.hh

@@ -67,6 +67,8 @@ namespace systems
  /// `<geometry>`: Detection region. Currently, only the `<box>` geometry is
  /// supported. The position of the geometry is derived from the pose of the
  /// containing model.
+ /// `<pose>`: Additional pose offset. This pose is added to the parent
+ /// model pose when computing the detection region.
 
  class IGNITION_GAZEBO_VISIBLE PerformerDetector
  : public System,
@@ -128,6 +130,9 @@ namespace systems
 
  /// \brief Whether the system has been initialized
  private: bool initialized{false};
+
+ /// \brief Additional pose offset for the plugin.
+ private: math::Pose3d poseOffset;
  };
 
  }