From 038b59a70b2cb602a4ae276a9de990e5a421977e Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:03:39 -0800
Subject: [PATCH 1/8] Removed particle_emitter

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 src/systems/particle_emitter/CMakeLists.txt   |   9 -
 .../particle_emitter/ParticleEmitter.cc       | 352 ------------------
 .../particle_emitter/ParticleEmitter.hh       | 144 -------
 3 files changed, 505 deletions(-)
 delete mode 100644 src/systems/particle_emitter/CMakeLists.txt
 delete mode 100644 src/systems/particle_emitter/ParticleEmitter.cc
 delete mode 100644 src/systems/particle_emitter/ParticleEmitter.hh

diff --git a/src/systems/particle_emitter/CMakeLists.txt b/src/systems/particle_emitter/CMakeLists.txt
deleted file mode 100644
index 9e75a90abf9..00000000000
--- a/src/systems/particle_emitter/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-gz_add_system(particle-emitter
-  SOURCES
-    ParticleEmitter.cc
-  PUBLIC_LINK_LIBS
-    ignition-common${IGN_COMMON_VER}::ignition-common${IGN_COMMON_VER}
-    ignition-msgs${IGN_MSGS_VER}::ignition-msgs${IGN_MSGS_VER}
-    ignition-plugin${IGN_PLUGIN_VER}::ignition-plugin${IGN_PLUGIN_VER}
-    ignition-transport${IGN_TRANSPORT_VER}::ignition-transport${IGN_TRANSPORT_VER}
-)
diff --git a/src/systems/particle_emitter/ParticleEmitter.cc b/src/systems/particle_emitter/ParticleEmitter.cc
deleted file mode 100644
index db1aa6b924d..00000000000
--- a/src/systems/particle_emitter/ParticleEmitter.cc
+++ /dev/null
@@ -1,352 +0,0 @@
-/*
- * Copyright (C) 2021 Open Source Robotics Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include <ignition/msgs/particle_emitter.pb.h>
-
-#include <mutex>
-#include <set>
-#include <string>
-
-#include <ignition/common/Profiler.hh>
-#include <ignition/math/Color.hh>
-#include <ignition/math/Vector3.hh>
-#include <ignition/msgs/Utility.hh>
-#include <ignition/plugin/Register.hh>
-#include <ignition/transport/Node.hh>
-
-#include <ignition/gazebo/components/Name.hh>
-#include <ignition/gazebo/components/ParticleEmitter.hh>
-#include <ignition/gazebo/components/Pose.hh>
-#include <ignition/gazebo/components/SourceFilePath.hh>
-#include <ignition/gazebo/Conversions.hh>
-#include <ignition/gazebo/Model.hh>
-#include <ignition/gazebo/SdfEntityCreator.hh>
-#include <ignition/gazebo/Util.hh>
-#include <sdf/Material.hh>
-#include "ParticleEmitter.hh"
-
-using namespace ignition;
-using namespace gazebo;
-using namespace systems;
-
-// Private data class.
-class ignition::gazebo::systems::ParticleEmitterPrivate
-{
-  /// \brief Callback for receiving particle emitter commands.
-  /// \param[in] _msg Particle emitter message.
-  public: void OnCmd(const ignition::msgs::ParticleEmitter &_msg);
-
-  /// \brief The particle emitter parsed from SDF.
-  public: ignition::msgs::ParticleEmitter emitter;
-
-  /// \brief The transport node.
-  public: ignition::transport::Node node;
-
-  /// \brief Particle emitter entity.
-  public: Entity emitterEntity{kNullEntity};
-
-  /// \brief The particle emitter command requested externally.
-  public: ignition::msgs::ParticleEmitter userCmd;
-
-  public: bool newDataReceived = false;
-
-  /// \brief A mutex to protect the user command.
-  public: std::mutex mutex;
-};
-
-//////////////////////////////////////////////////
-void ParticleEmitterPrivate::OnCmd(const msgs::ParticleEmitter &_msg)
-{
-  std::lock_guard<std::mutex> lock(this->mutex);
-  this->userCmd = _msg;
-  this->newDataReceived = true;
-}
-
-//////////////////////////////////////////////////
-ParticleEmitter::ParticleEmitter()
-  : System(), dataPtr(std::make_unique<ParticleEmitterPrivate>())
-{
-}
-
-//////////////////////////////////////////////////
-void ParticleEmitter::Configure(const Entity &_entity,
-    const std::shared_ptr<const sdf::Element> &_sdf,
-    EntityComponentManager &_ecm,
-    EventManager &_eventMgr)
-{
-  Model model = Model(_entity);
-
-  if (!model.Valid(_ecm))
-  {
-    ignerr << "ParticleEmitter plugin should be attached to a model entity. "
-           << "Failed to initialize." << std::endl;
-    return;
-  }
-
-  // Create a particle emitter entity.
-  this->dataPtr->emitterEntity = _ecm.CreateEntity();
-  if (this->dataPtr->emitterEntity == kNullEntity)
-  {
-    ignerr << "Failed to create a particle emitter entity" << std::endl;
-    return;
-  }
-
-  // allow_renaming
-  bool allowRenaming = false;
-  if (_sdf->HasElement("allow_renaming"))
-    allowRenaming = _sdf->Get<bool>("allow_renaming");
-
-  // Name.
-  std::string name = "particle_emitter_entity_" +
-      std::to_string(this->dataPtr->emitterEntity);
-  if (_sdf->HasElement("emitter_name"))
-  {
-    std::set<std::string> emitterNames;
-    std::string emitterName = _sdf->Get<std::string>("emitter_name");
-
-    // check to see if name is already taken
-    _ecm.Each<components::Name, components::ParticleEmitter>(
-        [&emitterNames](const Entity &, const components::Name *_name,
-                      const components::ParticleEmitter *)
-        {
-          emitterNames.insert(_name->Data());
-          return true;
-        });
-
-    name = emitterName;
-
-    // rename emitter if needed
-    if (emitterNames.find(emitterName) != emitterNames.end())
-    {
-      if (!allowRenaming)
-      {
-        ignwarn << "Entity named [" << name
-                << "] already exists and "
-                << "[allow_renaming] is false. Entity not spawned."
-                << std::endl;
-        return;
-      }
-      int counter = 0;
-      while (emitterNames.find(name) != emitterNames.end())
-      {
-        name = emitterName + "_" + std::to_string(++counter);
-      }
-      ignmsg << "Entity named [" << emitterName
-             << "] already exists. Renaming it to " << name << std::endl;
-    }
-  }
-  this->dataPtr->emitter.set_name(name);
-
-  // Type. The default type is point.
-  this->dataPtr->emitter.set_type(
-      ignition::msgs::ParticleEmitter_EmitterType_POINT);
-  std::string type = _sdf->Get<std::string>("type", "point").first;
-  if (type == "box")
-  {
-    this->dataPtr->emitter.set_type(
-      ignition::msgs::ParticleEmitter_EmitterType_BOX);
-  }
-  else if (type == "cylinder")
-  {
-    this->dataPtr->emitter.set_type(
-      ignition::msgs::ParticleEmitter_EmitterType_CYLINDER);
-  }
-  else if (type == "ellipsoid")
-  {
-    this->dataPtr->emitter.set_type(
-      ignition::msgs::ParticleEmitter_EmitterType_ELLIPSOID);
-  }
-  else if (type != "point")
-  {
-    ignerr << "Unknown emitter type [" << type << "]. Using [point] instead"
-           << std::endl;
-  }
-
-  // Pose.
-  ignition::math::Pose3d pose =
-    _sdf->Get<ignition::math::Pose3d>("pose");
-  ignition::msgs::Set(this->dataPtr->emitter.mutable_pose(), pose);
-
-  // Size.
-  ignition::math::Vector3d size = ignition::math::Vector3d::One;
-  if (_sdf->HasElement("size"))
-    size = _sdf->Get<ignition::math::Vector3d>("size");
-  ignition::msgs::Set(this->dataPtr->emitter.mutable_size(), size);
-
-  // Rate.
-  this->dataPtr->emitter.mutable_rate()->set_data(
-      _sdf->Get<double>("rate", 10).first);
-
-  // Duration.
-  this->dataPtr->emitter.mutable_duration()->set_data(
-      _sdf->Get<double>("duration", 0).first);
-
-  // Emitting.
-  this->dataPtr->emitter.mutable_emitting()->set_data(
-      _sdf->Get<bool>("emitting", false).first);
-
-  // Particle size.
-  size = ignition::math::Vector3d::One;
-  if (_sdf->HasElement("particle_size"))
-    size = _sdf->Get<ignition::math::Vector3d>("particle_size");
-  ignition::msgs::Set(this->dataPtr->emitter.mutable_particle_size(), size);
-
-  // Lifetime.
-  this->dataPtr->emitter.mutable_lifetime()->set_data(
-      _sdf->Get<double>("lifetime", 5).first);
-
-  // Material.
-  if (_sdf->HasElement("material"))
-  {
-    auto materialElem = _sdf->GetElementImpl("material");
-    sdf::Material material;
-    material.Load(materialElem);
-    ignition::msgs::Material materialMsg = convert<msgs::Material>(material);
-    this->dataPtr->emitter.mutable_material()->CopyFrom(materialMsg);
-  }
-
-  // Min velocity.
-  this->dataPtr->emitter.mutable_min_velocity()->set_data(
-    _sdf->Get<double>("min_velocity", 1).first);
-
-  // Max velocity.
-  this->dataPtr->emitter.mutable_max_velocity()->set_data(
-    _sdf->Get<double>("max_velocity", 1).first);
-
-  // Color start.
-  ignition::math::Color color = ignition::math::Color::White;
-  if (_sdf->HasElement("color_start"))
-    color = _sdf->Get<ignition::math::Color>("color_start");
-  ignition::msgs::Set(this->dataPtr->emitter.mutable_color_start(), color);
-
-  // Color end.
-  color = ignition::math::Color::White;
-  if (_sdf->HasElement("color_end"))
-    color = _sdf->Get<ignition::math::Color>("color_end");
-  ignition::msgs::Set(this->dataPtr->emitter.mutable_color_end(), color);
-
-  // Scale rate.
-  this->dataPtr->emitter.mutable_scale_rate()->set_data(
-    _sdf->Get<double>("scale_rate", 1).first);
-
-  // Color range image.
-  if (_sdf->HasElement("color_range_image"))
-  {
-    auto modelPath = _ecm.ComponentData<components::SourceFilePath>(_entity);
-    auto colorRangeImagePath = _sdf->Get<std::string>("color_range_image");
-    auto path = asFullPath(colorRangeImagePath, modelPath.value());
-
-    common::SystemPaths systemPaths;
-    systemPaths.SetFilePathEnv(kResourcePathEnv);
-    auto absolutePath = systemPaths.FindFile(path);
-
-    this->dataPtr->emitter.mutable_color_range_image()->set_data(
-        absolutePath);
-  }
-
-  // particle scatter ratio
-  const std::string scatterRatioKey = "particle_scatter_ratio";
-  if (_sdf->HasElement(scatterRatioKey))
-  {
-    // todo(anyone) add particle_scatter_ratio field in next release of ign-msgs
-    auto data = this->dataPtr->emitter.mutable_header()->add_data();
-    data->set_key(scatterRatioKey);
-    std::string *value = data->add_value();
-    *value = _sdf->Get<std::string>(scatterRatioKey);
-  }
-
-  igndbg << "Loading particle emitter:" << std::endl
-         << this->dataPtr->emitter.DebugString() << std::endl;
-
-  // Create components.
-  SdfEntityCreator sdfEntityCreator(_ecm, _eventMgr);
-  sdfEntityCreator.SetParent(this->dataPtr->emitterEntity, _entity);
-
-  _ecm.CreateComponent(this->dataPtr->emitterEntity,
-    components::Name(this->dataPtr->emitter.name()));
-
-  _ecm.CreateComponent(this->dataPtr->emitterEntity,
-    components::ParticleEmitter(this->dataPtr->emitter));
-
-  _ecm.CreateComponent(this->dataPtr->emitterEntity, components::Pose(pose));
-
-  // Advertise the topic to receive particle emitter commands.
-  const std::string kDefaultTopic =
-    "/model/" + model.Name(_ecm) + "/particle_emitter/" + name;
-  std::string topic = _sdf->Get<std::string>("topic", kDefaultTopic).first;
-  if (!this->dataPtr->node.Subscribe(
-         topic, &ParticleEmitterPrivate::OnCmd, this->dataPtr.get()))
-  {
-    ignerr << "Error subscribing to topic [" << topic << "]. "
-        << "Particle emitter will not receive updates." << std::endl;
-    return;
-  }
-  igndbg << "Subscribed to " << topic << " for receiving particle emitter "
-         << "updates" << std::endl;
-}
-
-//////////////////////////////////////////////////
-void ParticleEmitter::PreUpdate(const ignition::gazebo::UpdateInfo &_info,
-    ignition::gazebo::EntityComponentManager &_ecm)
-{
-  IGN_PROFILE("ParticleEmitter::PreUpdate");
-
-  std::lock_guard<std::mutex> lock(this->dataPtr->mutex);
-
-  if (!this->dataPtr->newDataReceived)
-    return;
-
-  // Nothing left to do if paused.
-  if (_info.paused)
-    return;
-
-  this->dataPtr->newDataReceived = false;
-
-  // Create component.
-  auto emitterComp = _ecm.Component<components::ParticleEmitterCmd>(
-      this->dataPtr->emitterEntity);
-  if (!emitterComp)
-  {
-    _ecm.CreateComponent(
-        this->dataPtr->emitterEntity,
-        components::ParticleEmitterCmd(this->dataPtr->userCmd));
-  }
-  else
-  {
-    emitterComp->Data() = this->dataPtr->userCmd;
-
-    // Note: we process the cmd component in RenderUtil but if there is only
-    // rendering on the gui side, it will not be able to remove the cmd
-    // component from the ECM. It seems like adding OneTimeChange here will make
-    // sure the cmd component is found again in Each call on GUI side.
-    // todo(anyone) find a better way to process this cmd component in
-    // RenderUtil.cc
-    _ecm.SetChanged(this->dataPtr->emitterEntity,
-        components::ParticleEmitterCmd::typeId,
-        ComponentState::OneTimeChange);
-  }
-
-  igndbg << "New ParticleEmitterCmd component created" << std::endl;
-}
-
-IGNITION_ADD_PLUGIN(ParticleEmitter,
-                    ignition::gazebo::System,
-                    ParticleEmitter::ISystemConfigure,
-                    ParticleEmitter::ISystemPreUpdate)
-
-IGNITION_ADD_PLUGIN_ALIAS(ParticleEmitter,
-                          "ignition::gazebo::systems::ParticleEmitter")
diff --git a/src/systems/particle_emitter/ParticleEmitter.hh b/src/systems/particle_emitter/ParticleEmitter.hh
deleted file mode 100644
index 6a3da57d233..00000000000
--- a/src/systems/particle_emitter/ParticleEmitter.hh
+++ /dev/null
@@ -1,144 +0,0 @@
-/*
- * Copyright (C) 2021 Open Source Robotics Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-#ifndef IGNITION_GAZEBO_SYSTEMS_PARTICLE_EMITTER_HH_
-#define IGNITION_GAZEBO_SYSTEMS_PARTICLE_EMITTER_HH_
-
-#include <memory>
-
-#include <ignition/gazebo/System.hh>
-
-namespace ignition
-{
-namespace gazebo
-{
-// Inline bracket to help doxygen filtering.
-inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
-namespace systems
-{
-  class ParticleEmitterPrivate;
-
-  /// \brief A system for creating a particle emitter.
-  ///
-  /// This system will be deprecated in Igition Fortress. Please consider
-  /// using the ParticleEmitter2 system.
-  ///
-  /// System parameters
-  ///
-  /// `<emitter_name>`: Unique name for the particle emitter. The name will be
-  ///                   automatically generated if this parameter is not set.
-  /// `<allow_renaming>`: Rename the particle emitter if one with the same name
-  ///                     already exists. Default is false.
-  /// `<type>`: The emitter type (point, box, cylinder, ellipsoid).
-  ///           Default value is point.
-  /// `<pose>`: The pose of the emitter. Default value is {0, 0, 0, 0, 0, 0}.
-  /// `<size>`: The size of the emitter where the particles are sampled.
-  ///           Default value is (1, 1, 1).
-  ///           Note that the interpretation of the emitter area varies
-  ///           depending on the emmiter type:
-  ///             - point: The area is ignored.
-  ///             - box: The area is interpreted as width X height X depth.
-  ///             - cylinder: The area is interpreted as the bounding box of the
-  ///                         cilinder. The cylinder is oriented along the
-  ///                         Z-axis.
-  ///             - ellipsoid: The area is interpreted as the bounding box of an
-  ///                          ellipsoid shaped area, i.e. a sphere or
-  ///                          squashed-sphere area. The parameters are again
-  ///                          identical to EM_BOX, except that the dimensions
-  ///                          describe the widest points along each of the
-  ///                          axes.
-  /// `<rate>`: How many particles per second should be emitted.
-  ///           Default value is 10.
-  /// `<duration`>: The number of seconds the emitter is active. A value of 0
-  ///               means infinite duration. Default value is 0.
-  /// `<emitting>`: This is used to turn on or off particle emission.
-  ///               Default value is false.
-  /// `<particle_size>`: Set the particle dimensions (width, height, depth).
-  ///                    Default value is {1, 1, 1}.
-  /// `<lifetime>`: Set the number of seconds each particle will ’live’ for
-  ///               before being destroyed. Default value is 5.
-  /// `<material>`: Sets the material which all particles in the emitter will
-  ///               use.
-  /// `<min_velocity>`: Sets a minimum velocity for each particle (m/s).
-  ///                   Default value is 1.
-  /// `<max_velocity>`: Sets a maximum velocity for each particle (m/s).
-  ///                   Default value is 1.
-  /// `<color_start>`: Sets the starting color for all particle emitted.
-  ///                  The actual color will be interpolated between this color
-  ///                  and the one set under <color_end>.
-  ///                  Color::White is the default color for the particles
-  ///                  unless a specific function is used.
-  ///                  To specify a color, RGB values should be passed in.
-  ///                  For example, to specify red, a user should enter:
-  ///                  <color_start>1 0 0</color_start>
-  ///                  Note that this function overrides the particle colors set
-  ///                  with <color_range_image>.
-  /// `<color_end>`: Sets the end color for all particle emitted.
-  ///                The actual color will be interpolated between this color
-  ///                and the one set under <color_start>.
-  ///                Color::White is the default color for the particles
-  ///                unless a specific function is used (see color_start for
-  ///                more information about defining custom colors with RGB
-  ///                values).
-  ///                Note that this function overrides the particle colors set
-  ///                with <color_range_image>.
-  /// `<scale_rate>`: Sets the amount by which to scale the particles in both x
-  ///                 and y direction per second. Default value is 1.
-  /// `<color_range_image>`: Sets the path to the color image used as an
-  ///                        affector. This affector modifies the color of
-  ///                        particles in flight. The colors are taken from a
-  ///                        specified image file. The range of color values
-  ///                        begins from the left side of the image and move to
-  ///                        the right over the lifetime of the particle,
-  ///                        therefore only the horizontal dimension of the
-  ///                        image is used.
-  ///                        Note that this function overrides the particle
-  ///                        colors set with <color_start> and <color_end>.
-  /// `<topic>`: Topic used to update particle emitter properties at runtime.
-  ///            The default topic is
-  ///            /model/<model_name>/particle_emitter/<emitter_name>
-  ///            Note that the emitter id and name may not be changed.
-  ///            See the examples/worlds/particle_emitter.sdf example world for
-  ///            example usage.
-  class ParticleEmitter
-      : public System,
-        public ISystemConfigure,
-        public ISystemPreUpdate
-  {
-    /// \brief Constructor
-    public: IGN_DEPRECATED(6) ParticleEmitter();
-
-    // Documentation inherited
-    public: void Configure(const Entity &_entity,
-                           const std::shared_ptr<const sdf::Element> &_sdf,
-                           EntityComponentManager &_ecm,
-                           EventManager &_eventMgr) override;
-
-    // Documentation inherited
-    public: void PreUpdate(
-                const ignition::gazebo::UpdateInfo &_info,
-                ignition::gazebo::EntityComponentManager &_ecm) override;
-
-    /// \brief Private data pointer
-    private: std::unique_ptr<ParticleEmitterPrivate> dataPtr;
-  };
-  }
-}
-}
-}
-
-#endif
-

From 84df8174c49cc707d51e2171e73b09d1f199156e Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:06:11 -0800
Subject: [PATCH 2/8] Copied particle_emitter2 to particle_emitter

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 src/systems/particle_emitter/CMakeLists.txt   |   9 +
 .../particle_emitter/ParticleEmitter.cc       | 255 ++++++++++++++++++
 .../particle_emitter/ParticleEmitter.hh       |  69 +++++
 3 files changed, 333 insertions(+)
 create mode 100644 src/systems/particle_emitter/CMakeLists.txt
 create mode 100644 src/systems/particle_emitter/ParticleEmitter.cc
 create mode 100644 src/systems/particle_emitter/ParticleEmitter.hh

diff --git a/src/systems/particle_emitter/CMakeLists.txt b/src/systems/particle_emitter/CMakeLists.txt
new file mode 100644
index 00000000000..9e75a90abf9
--- /dev/null
+++ b/src/systems/particle_emitter/CMakeLists.txt
@@ -0,0 +1,9 @@
+gz_add_system(particle-emitter
+  SOURCES
+    ParticleEmitter.cc
+  PUBLIC_LINK_LIBS
+    ignition-common${IGN_COMMON_VER}::ignition-common${IGN_COMMON_VER}
+    ignition-msgs${IGN_MSGS_VER}::ignition-msgs${IGN_MSGS_VER}
+    ignition-plugin${IGN_PLUGIN_VER}::ignition-plugin${IGN_PLUGIN_VER}
+    ignition-transport${IGN_TRANSPORT_VER}::ignition-transport${IGN_TRANSPORT_VER}
+)
diff --git a/src/systems/particle_emitter/ParticleEmitter.cc b/src/systems/particle_emitter/ParticleEmitter.cc
new file mode 100644
index 00000000000..5b455e11d72
--- /dev/null
+++ b/src/systems/particle_emitter/ParticleEmitter.cc
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2021 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <ignition/msgs/particle_emitter.pb.h>
+#include <ignition/msgs/particle_emitter_v.pb.h>
+
+#include <map>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include <ignition/common/Profiler.hh>
+#include <ignition/msgs/Utility.hh>
+#include <ignition/plugin/Register.hh>
+#include <ignition/transport/Node.hh>
+
+#include <ignition/gazebo/components/Name.hh>
+#include <ignition/gazebo/components/ParentEntity.hh>
+#include <ignition/gazebo/components/ParticleEmitter.hh>
+#include <ignition/gazebo/components/Pose.hh>
+#include <ignition/gazebo/Util.hh>
+#include "ParticleEmitter.hh"
+
+using namespace std::chrono_literals;
+
+using namespace ignition;
+using namespace gazebo;
+using namespace systems;
+
+// Private data class.
+class ignition::gazebo::systems::ParticleEmitterPrivate
+{
+  /// \brief Callback for receiving particle emitter commands.
+  /// \param[in] _msg Particle emitter message.
+  public: void OnCmd(const ignition::msgs::ParticleEmitter &_msg,
+              const transport::MessageInfo &_info);
+
+  public: bool EmittersService(ignition::msgs::ParticleEmitter_V &_res);
+
+  /// \brief The transport node.
+  public: ignition::transport::Node node;
+
+  /// \brief Map of topic name to particle emitter entity.
+  public: std::map<std::string, Entity> emitterTopicMap;
+
+  /// \brief Map of Entity to particle emitter command requested externally.
+  public: std::map<Entity, ignition::msgs::ParticleEmitter> userCmd;
+
+  /// \brief A mutex to protect the user command.
+  public: std::mutex mutex;
+
+  /// \brief Protects serviceMsg.
+  public: std::mutex serviceMutex;
+
+  /// \brief Filled on demand for the emitter service.
+  public: msgs::ParticleEmitter_V serviceMsg;
+};
+
+//////////////////////////////////////////////////
+void ParticleEmitterPrivate::OnCmd(const msgs::ParticleEmitter &_msg,
+    const transport::MessageInfo &_info)
+{
+  std::lock_guard<std::mutex> lock(this->mutex);
+  std::map<std::string, Entity>::const_iterator iter =
+    this->emitterTopicMap.find(_info.Topic());
+  if (iter != this->emitterTopicMap.end())
+  {
+    this->userCmd[iter->second].CopyFrom(_msg);
+  }
+  else
+  {
+    ignwarn << "Topic[" << _info.Topic() << "] is not known to the particle "
+      "emitter system. The requested command will be ignored.\n";
+  }
+}
+
+//////////////////////////////////////////////////
+bool ParticleEmitterPrivate::EmittersService(
+    ignition::msgs::ParticleEmitter_V &_res)
+{
+  _res.Clear();
+
+  std::scoped_lock<std::mutex> lock(this->serviceMutex);
+  _res.CopyFrom(this->serviceMsg);
+  return true;
+}
+
+//////////////////////////////////////////////////
+ParticleEmitter::ParticleEmitter()
+  : System(), dataPtr(std::make_unique<ParticleEmitterPrivate>())
+{
+}
+
+//////////////////////////////////////////////////
+void ParticleEmitter::Configure(const Entity &_entity,
+    const std::shared_ptr<const sdf::Element> & /*_sdf*/,
+    EntityComponentManager &_ecm,
+    EventManager & /*_eventMgr*/)
+{
+  // World
+  const components::Name *name = _ecm.Component<components::Name>(_entity);
+  if (name == nullptr)
+  {
+    ignerr << "World with id: " << _entity
+           << " has no name. ParticleEmitter cannot create transport topics\n";
+    return;
+  }
+
+  std::string emittersService = "/world/" + name->Data() + "/particle_emitters";
+  if (this->dataPtr->node.Advertise(emittersService,
+        &ParticleEmitterPrivate::EmittersService, this->dataPtr.get()))
+  {
+    ignmsg << "Serving particle emitter information on ["
+      << emittersService << "]" << std::endl;
+  }
+  else
+  {
+    ignerr << "Something went wrong, failed to advertise [" << emittersService
+           << "]" << std::endl;
+  }
+}
+
+//////////////////////////////////////////////////
+void ParticleEmitter::PreUpdate(const ignition::gazebo::UpdateInfo &_info,
+    ignition::gazebo::EntityComponentManager &_ecm)
+{
+  IGN_PROFILE("ParticleEmitter::PreUpdate");
+
+  std::lock_guard<std::mutex> lock(this->dataPtr->mutex);
+
+  // Create particle emitters
+  {
+    std::lock_guard<std::mutex> serviceLock(this->dataPtr->serviceMutex);
+    _ecm.EachNew<components::ParticleEmitter, components::ParentEntity,
+      components::Pose>(
+      [&](const Entity &_entity,
+          const components::ParticleEmitter *_emitter,
+          const components::ParentEntity *_parent,
+          const components::Pose *_pose)->bool
+        {
+          std::string topic;
+
+          // Get the topic information from the header, which is currently a
+          // hack to avoid breaking the particle_emitter.proto message.
+          if (_emitter->Data().has_header())
+          {
+            for (const auto data : _emitter->Data().header().data())
+            {
+              if (data.key() == "topic" && !data.value().empty())
+              {
+                topic = data.value(0);
+              }
+            }
+          }
+
+          // If a topic has not been specified, then generate topic based
+          // on the scoped name.
+          topic = !topic.empty() ? topic :
+            topicFromScopedName(_entity, _ecm) + "/cmd";
+
+          // Subscribe to the topic that receives particle emitter commands.
+          if (!this->dataPtr->node.Subscribe(
+                topic, &ParticleEmitterPrivate::OnCmd, this->dataPtr.get()))
+          {
+            ignerr << "Error subscribing to topic [" << topic << "]. "
+              << "Particle emitter will not receive updates." << std::endl;
+            return false;
+          }
+          ignmsg << "Particle emitter["
+            << scopedName(_entity, _ecm, "::", false) << "] subscribed "
+            << "to command messages on topic[" << topic << "]\n";
+
+          // Store the topic name so that we can apply user commands
+          // correctly.
+          this->dataPtr->emitterTopicMap[topic] = _entity;
+
+          // Store the emitter information in the service message, which
+          // can then be used in the particle_emitters service.
+          msgs::ParticleEmitter *emitterMsg =
+            this->dataPtr->serviceMsg.add_particle_emitter();
+          emitterMsg->CopyFrom(_emitter->Data());
+          msgs::Set(emitterMsg->mutable_pose(), _pose->Data());
+
+          // Set the topic information if it was not set via SDF.
+          if (!emitterMsg->has_header())
+          {
+            auto headerData = emitterMsg->mutable_header()->add_data();
+            headerData->set_key("topic");
+            headerData->add_value(topic);
+          }
+
+          // Set the particle emitter frame
+          auto frameData = emitterMsg->mutable_header()->add_data();
+          frameData->set_key("frame");
+          frameData->add_value(
+              removeParentScope(
+                scopedName(_parent->Data(), _ecm, "::", false), "::"));
+
+          return true;
+        });
+  }
+
+  if (this->dataPtr->userCmd.empty() || _info.paused)
+    return;
+
+  // Process each command
+  for (const auto cmd : this->dataPtr->userCmd)
+  {
+    // Create component.
+    auto emitterComp = _ecm.Component<components::ParticleEmitterCmd>(
+        cmd.first);
+    if (!emitterComp)
+    {
+      _ecm.CreateComponent(cmd.first,
+          components::ParticleEmitterCmd(cmd.second));
+    }
+    else
+    {
+      emitterComp->Data() = cmd.second;
+
+      // Note: we process the cmd component in RenderUtil but if there is only
+      // rendering on the gui side, it will not be able to remove the cmd
+      // component from the ECM. It seems like adding OneTimeChange here will
+      // make sure the cmd component is found again in Each call on GUI side.
+      // todo(anyone) find a better way to process this cmd component in
+      // RenderUtil.cc
+      _ecm.SetChanged(cmd.first,
+          components::ParticleEmitterCmd::typeId,
+          ComponentState::OneTimeChange);
+    }
+  }
+  this->dataPtr->userCmd.clear();
+}
+
+IGNITION_ADD_PLUGIN(ParticleEmitter,
+                    ignition::gazebo::System,
+                    ParticleEmitter::ISystemConfigure,
+                    ParticleEmitter::ISystemPreUpdate)
+
+IGNITION_ADD_PLUGIN_ALIAS(ParticleEmitter,
+                          "ignition::gazebo::systems::ParticleEmitter")
diff --git a/src/systems/particle_emitter/ParticleEmitter.hh b/src/systems/particle_emitter/ParticleEmitter.hh
new file mode 100644
index 00000000000..ed144dab4d0
--- /dev/null
+++ b/src/systems/particle_emitter/ParticleEmitter.hh
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2021 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#ifndef IGNITION_GAZEBO_SYSTEMS_PARTICLE_EMITTER_HH_
+#define IGNITION_GAZEBO_SYSTEMS_PARTICLE_EMITTER_HH_
+
+#include <memory>
+
+#include <ignition/gazebo/System.hh>
+
+namespace ignition
+{
+namespace gazebo
+{
+// Inline bracket to help doxygen filtering.
+inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
+namespace systems
+{
+  class ParticleEmitterPrivate;
+
+  /// \brief A system for running and managing particle emitters. A particle
+  /// emitter is defined using the <particle_emitter> SDF element.
+  ///
+  /// This system will create a transport subscriber for each
+  /// <particle_emitter> using the child <topic> name. If a <topic> is not
+  /// specified, the following topic naming scheme will be used:
+  /// `/model/{model_name}/link/{link_name}/particle_emitter/{emitter_name}/cmd`
+  class ParticleEmitter
+      : public System,
+        public ISystemConfigure,
+        public ISystemPreUpdate
+  {
+    /// \brief Constructor
+    public: ParticleEmitter();
+
+    // Documentation inherited
+    public: void Configure(const Entity &_entity,
+                           const std::shared_ptr<const sdf::Element> &_sdf,
+                           EntityComponentManager &_ecm,
+                           EventManager &_eventMgr) override;
+
+    // Documentation inherited
+    public: void PreUpdate(
+                const ignition::gazebo::UpdateInfo &_info,
+                ignition::gazebo::EntityComponentManager &_ecm) override;
+
+    /// \brief Private data pointer
+    private: std::unique_ptr<ParticleEmitterPrivate> dataPtr;
+  };
+  }
+}
+}
+}
+
+#endif
+

From 4e39df2d241d44886d80021e09b1f812634705d3 Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:08:15 -0800
Subject: [PATCH 3/8] remove particle_emitter example world and test files

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 examples/worlds/particle_emitter.sdf |  95 --------------
 test/integration/particle_emitter.cc | 178 ---------------------------
 test/worlds/particle_emitter.sdf     | 107 ----------------
 3 files changed, 380 deletions(-)
 delete mode 100644 examples/worlds/particle_emitter.sdf
 delete mode 100644 test/integration/particle_emitter.cc
 delete mode 100644 test/worlds/particle_emitter.sdf

diff --git a/examples/worlds/particle_emitter.sdf b/examples/worlds/particle_emitter.sdf
deleted file mode 100644
index bf372aeef24..00000000000
--- a/examples/worlds/particle_emitter.sdf
+++ /dev/null
@@ -1,95 +0,0 @@
-<?xml version="1.0" ?>
-
-<!-- NOTE: This world uses a particle emitter that is implemented as
-     a plugin. We recommend using particle emitters based on the SDF
-     specification. See the test/worlds/particle_emitter2.sdf example.
--->
-
-<!--
-  Launch this example with:
-
-      ign gazebo -r particle_emitter.sdf
-
-  Try modifying some parameters of the emitter:
-
-    To disable the particle emitter:
-
-      ign topic -t /model/smoke_generator/particle_emitter/smoke_generator -m ignition.msgs.ParticleEmitter -p 'name: "smoke_generator" pose { position { } orientation { w: 1 } } size { x: 1 y: 1 z: 1 } rate: 10 emitting: false particle_size { x: 1 y: 1 z: 1 } lifetime: 2 material { header { data { key: "double_sided" value: "0" } } ambient { a: 1 } diffuse { r: 0.7 g: 0.7 b: 0.7 a: 1 } specular { a: 1 } emissive { a: 1 } lighting: true pbr { type: METAL albedo_map: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smoke.png" metalness: 0.5 roughness: 0.5 } } min_velocity: 10 max_velocity: 20 color_start { r: 1 g: 1 b: 1 a: 1 } color_end { r: 1 g: 1 b: 1 a: 1 } scale_rate: 10 color_range_image: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smokecolors.png"'
-
-    Enable back the particle emitter:
-
-      ign topic -t /model/smoke_generator/particle_emitter/smoke_generator -m ignition.msgs.ParticleEmitter -p 'name: "smoke_generator" pose { position { } orientation { w: 1 } } size { x: 1 y: 1 z: 1 } rate: 10 emitting: true particle_size { x: 1 y: 1 z: 1 } lifetime: 2 material { header { data { key: "double_sided" value: "0" } } ambient { a: 1 } diffuse { r: 0.7 g: 0.7 b: 0.7 a: 1 } specular { a: 1 } emissive { a: 1 } lighting: true pbr { type: METAL albedo_map: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smoke.png" metalness: 0.5 roughness: 0.5 } } min_velocity: 10 max_velocity: 20 color_start { r: 1 g: 1 b: 1 a: 1 } color_end { r: 1 g: 1 b: 1 a: 1 } scale_rate: 10 color_range_image: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smokecolors.png"'
-
-    Then, change the particle rate:
-
-      ign topic -t /model/smoke_generator/particle_emitter/smoke_generator -m ignition.msgs.ParticleEmitter -p 'name: "smoke_generator" pose { position { } orientation { w: 1 } } size { x: 1 y: 1 z: 1 } rate: 100 emitting: true particle_size { x: 1 y: 1 z: 1 } lifetime: 2 material { header { data { key: "double_sided" value: "0" } } ambient { a: 1 } diffuse { r: 0.7 g: 0.7 b: 0.7 a: 1 } specular { a: 1 } emissive { a: 1 } lighting: true pbr { type: METAL albedo_map: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smoke.png" metalness: 0.5 roughness: 0.5 } } min_velocity: 10 max_velocity: 20 color_start { r: 1 g: 1 b: 1 a: 1 } color_end { r: 1 g: 1 b: 1 a: 1 } scale_rate: 10 color_range_image: "/home/caguero/.ignition/fuel/fuel.ignitionrobotics.org/caguero/models/smoke_generator/2/materials/textures/smokecolors.png"'
--->
-
-<sdf version="1.6">
-  <world name="particle_emitters">
-
-    <physics name="1ms" type="ode">
-      <max_step_size>0.001</max_step_size>
-      <real_time_factor>1.0</real_time_factor>
-    </physics>
-    <plugin
-      filename="ignition-gazebo-physics-system"
-      name="ignition::gazebo::systems::Physics">
-    </plugin>
-    <plugin
-      filename="ignition-gazebo-user-commands-system"
-      name="ignition::gazebo::systems::UserCommands">
-    </plugin>
-    <plugin
-      filename="ignition-gazebo-scene-broadcaster-system"
-      name="ignition::gazebo::systems::SceneBroadcaster">
-    </plugin>
-
-    <light type="directional" name="sun">
-      <cast_shadows>true</cast_shadows>
-      <pose>0 0 10 0 0 0</pose>
-      <diffuse>1 1 1 1</diffuse>
-      <specular>0.5 0.5 0.5 1</specular>
-      <attenuation>
-        <range>1000</range>
-        <constant>0.9</constant>
-        <linear>0.01</linear>
-        <quadratic>0.001</quadratic>
-      </attenuation>
-      <direction>-0.5 0.1 -0.9</direction>
-    </light>
-
-    <model name="ground_plane">
-      <static>true</static>
-      <link name="link">
-        <collision name="collision">
-          <geometry>
-            <plane>
-              <normal>0 0 1</normal>
-            </plane>
-          </geometry>
-        </collision>
-        <visual name="visual">
-          <geometry>
-            <plane>
-              <normal>0 0 1</normal>
-              <size>100 100</size>
-            </plane>
-          </geometry>
-          <material>
-            <ambient>0.8 0.8 0.8 1</ambient>
-            <diffuse>0.8 0.8 0.8 1</diffuse>
-            <specular>0.8 0.8 0.8 1</specular>
-          </material>
-        </visual>
-      </link>
-    </model>
-
-    <include>
-      <uri>https://fuel.ignitionrobotics.org/1.0/caguero/models/smoke_generator</uri>
-    </include>
-
-  </world>
-</sdf>
-
-
diff --git a/test/integration/particle_emitter.cc b/test/integration/particle_emitter.cc
deleted file mode 100644
index 0b95df94326..00000000000
--- a/test/integration/particle_emitter.cc
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright (C) 2021 Open Source Robotics Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include <gtest/gtest.h>
-
-#include <string>
-
-#include <ignition/common/Util.hh>
-
-#include <ignition/math/Color.hh>
-#include <ignition/msgs/Utility.hh>
-
-#include "ignition/gazebo/Entity.hh"
-#include "ignition/gazebo/Server.hh"
-#include "ignition/gazebo/SystemLoader.hh"
-#include "ignition/gazebo/components/Name.hh"
-#include "ignition/gazebo/components/ParticleEmitter.hh"
-#include "ignition/gazebo/components/Pose.hh"
-#include "ignition/gazebo/test_config.hh"
-
-#include "helpers/EnvTestFixture.hh"
-#include "helpers/Relay.hh"
-
-using namespace ignition;
-using namespace gazebo;
-
-class ParticleEmitterTest : public InternalFixture<::testing::Test>
-{
-  public: void LoadWorld(const std::string &_path, bool _useLevels = false)
-  {
-    this->serverConfig.SetSdfFile(
-        common::joinPaths(PROJECT_SOURCE_PATH, _path));
-    this->serverConfig.SetUseLevels(_useLevels);
-
-    this->server = std::make_unique<Server>(this->serverConfig);
-    EXPECT_FALSE(this->server->Running());
-    EXPECT_FALSE(*this->server->Running(0));
-    using namespace std::chrono_literals;
-    this->server->SetUpdatePeriod(1ns);
-  }
-
-  public: ServerConfig serverConfig;
-  public: std::unique_ptr<Server> server;
-};
-
-/////////////////////////////////////////////////
-// Load an SDF with a particle emitter and verify its properties.
-TEST_F(ParticleEmitterTest, SDFLoad)
-{
-  bool updateCustomChecked{false};
-  bool updateDefaultChecked{false};
-
-  this->LoadWorld("test/worlds/particle_emitter.sdf");
-
-  // Create a system that checks a particle emitter.
-  test::Relay testSystem;
-  testSystem.OnPostUpdate([&](const gazebo::UpdateInfo &,
-                              const gazebo::EntityComponentManager &_ecm)
-      {
-        _ecm.Each<components::ParticleEmitter,
-                  components::Name,
-                  components::Pose>(
-            [&](const ignition::gazebo::Entity &_entity,
-                const components::ParticleEmitter *_emitter,
-                const components::Name *_name,
-                const components::Pose *_pose) -> bool
-            {
-
-              if (_name->Data() == "smoke_emitter")
-              {
-                updateCustomChecked = true;
-
-                EXPECT_EQ("smoke_emitter", _name->Data());
-                EXPECT_EQ(_name->Data(), _emitter->Data().name());
-                EXPECT_EQ(msgs::ParticleEmitter_EmitterType_BOX,
-                    _emitter->Data().type());
-                EXPECT_EQ(math::Pose3d(0, 1, 0, 0, 0, 0), _pose->Data());
-                EXPECT_EQ(_pose->Data(),
-                    msgs::Convert(_emitter->Data().pose()));
-                EXPECT_EQ(math::Vector3d(2, 2, 2),
-                    msgs::Convert(_emitter->Data().size()));
-                EXPECT_DOUBLE_EQ(5.0, _emitter->Data().rate().data());
-                EXPECT_DOUBLE_EQ(1.0, _emitter->Data().duration().data());
-                EXPECT_TRUE(_emitter->Data().emitting().data());
-                EXPECT_EQ(math::Vector3d(3, 3, 3),
-                    msgs::Convert(_emitter->Data().particle_size()));
-                EXPECT_DOUBLE_EQ(2.0, _emitter->Data().lifetime().data());
-                // TODO(anyone) add material check here
-                EXPECT_DOUBLE_EQ(10.0,
-                    _emitter->Data().min_velocity().data());
-                EXPECT_DOUBLE_EQ(20.0,
-                    _emitter->Data().max_velocity().data());
-                EXPECT_EQ(math::Color::Blue,
-                    msgs::Convert(_emitter->Data().color_start()));
-                EXPECT_EQ(math::Color::Green,
-                    msgs::Convert(_emitter->Data().color_end()));
-                EXPECT_DOUBLE_EQ(10.0, _emitter->Data().scale_rate().data());
-
-                // color range image is empty because the emitter system
-                // will not be able to find a file that does not exist
-                // TODO(anyone) this should return  "/path/to/dummy_image.png"
-                // and let rendering do the findFile instead
-                EXPECT_EQ(std::string(),
-                    _emitter->Data().color_range_image().data());
-
-                // particle scatter ratio is temporarily stored in header
-                bool hasParticleScatterRatio = false;
-                for (int i = 0; i < _emitter->Data().header().data_size(); ++i)
-                {
-                  for (int j = 0;
-                      j < _emitter->Data().header().data(i).value_size(); ++j)
-                  {
-                    if (_emitter->Data().header().data(i).key() ==
-                        "particle_scatter_ratio")
-                    {
-                      EXPECT_DOUBLE_EQ(0.01, math::parseFloat(
-                          _emitter->Data().header().data(i).value(0)));
-                      hasParticleScatterRatio = true;
-                    }
-                  }
-                }
-                EXPECT_TRUE(hasParticleScatterRatio);
-              }
-              else
-              {
-                updateDefaultChecked = true;
-
-                EXPECT_TRUE(_name->Data().find(std::to_string(_entity))
-                    != std::string::npos);
-                EXPECT_EQ(_name->Data(), _emitter->Data().name());
-                EXPECT_EQ(msgs::ParticleEmitter_EmitterType_POINT,
-                    _emitter->Data().type());
-                EXPECT_EQ(math::Pose3d(0, 0, 0, 0, 0, 0), _pose->Data());
-                EXPECT_EQ(_pose->Data(),
-                    msgs::Convert(_emitter->Data().pose()));
-                EXPECT_EQ(math::Vector3d(1, 1, 1),
-                    msgs::Convert(_emitter->Data().size()));
-                EXPECT_DOUBLE_EQ(10.0, _emitter->Data().rate().data());
-                EXPECT_DOUBLE_EQ(0.0, _emitter->Data().duration().data());
-                EXPECT_FALSE(_emitter->Data().emitting().data());
-                EXPECT_EQ(math::Vector3d(1, 1, 1),
-                    msgs::Convert(_emitter->Data().particle_size()));
-                EXPECT_DOUBLE_EQ(5.0, _emitter->Data().lifetime().data());
-                // TODO(anyone) add material check here
-                EXPECT_DOUBLE_EQ(1.0, _emitter->Data().min_velocity().data());
-                EXPECT_DOUBLE_EQ(1.0, _emitter->Data().max_velocity().data());
-                EXPECT_EQ(math::Color::White,
-                    msgs::Convert(_emitter->Data().color_start()));
-                EXPECT_EQ(math::Color::White,
-                    msgs::Convert(_emitter->Data().color_end()));
-                EXPECT_DOUBLE_EQ(1.0, _emitter->Data().scale_rate().data());
-                EXPECT_EQ("", _emitter->Data().color_range_image().data());
-              }
-
-              return true;
-            });
-      });
-
-  this->server->AddSystem(testSystem.systemPtr);
-  this->server->Run(true, 1, false);
-
-  EXPECT_TRUE(updateCustomChecked);
-  EXPECT_TRUE(updateDefaultChecked);
-}
diff --git a/test/worlds/particle_emitter.sdf b/test/worlds/particle_emitter.sdf
deleted file mode 100644
index 0d15a8c2dc0..00000000000
--- a/test/worlds/particle_emitter.sdf
+++ /dev/null
@@ -1,107 +0,0 @@
-<?xml version="1.0" ?>
-<sdf version="1.6">
-  <world name="particle_emitters">
-
-    <physics name="1ms" type="ode">
-      <max_step_size>0.001</max_step_size>
-      <real_time_factor>1.0</real_time_factor>
-    </physics>
-
-    <light type="directional" name="sun">
-      <cast_shadows>true</cast_shadows>
-      <pose>0 0 10 0 0 0</pose>
-      <diffuse>1 1 1 1</diffuse>
-      <specular>0.5 0.5 0.5 1</specular>
-      <attenuation>
-        <range>1000</range>
-        <constant>0.9</constant>
-        <linear>0.01</linear>
-        <quadratic>0.001</quadratic>
-      </attenuation>
-      <direction>-0.5 0.1 -0.9</direction>
-    </light>
-
-    <model name="ground_plane">
-      <static>true</static>
-      <link name="link">
-        <collision name="collision">
-          <geometry>
-            <plane>
-              <normal>0 0 1</normal>
-            </plane>
-          </geometry>
-        </collision>
-        <visual name="visual">
-          <geometry>
-            <plane>
-              <normal>0 0 1</normal>
-              <size>100 100</size>
-            </plane>
-          </geometry>
-          <material>
-            <ambient>0.8 0.8 0.8 1</ambient>
-            <diffuse>0.8 0.8 0.8 1</diffuse>
-            <specular>0.8 0.8 0.8 1</specular>
-          </material>
-        </visual>
-      </link>
-    </model>
-
-    <!-- test custom parameters -->
-    <model name="smoke_generator_demo_model">
-      <pose>0 0 0 0 0 0</pose>
-      <static>true</static>
-      <link name="link">
-        <visual name="visual">
-          <geometry>
-            <box>
-              <size>1 1 1</size>
-            </box>
-          </geometry>
-        </visual>
-      </link>
-
-      <plugin filename="ignition-gazebo-particle-emitter-system"
-        name="ignition::gazebo::systems::ParticleEmitter">
-        <emitter_name>smoke_emitter</emitter_name>
-        <type>box</type>
-        <pose>0 1 0 0 0 0</pose>
-        <size>2 2 2</size>
-        <rate>5</rate>
-        <duration>1</duration>
-        <emitting>true</emitting>
-        <particle_size>3 3 3</particle_size>
-        <lifetime>2</lifetime>
-        <!-- TODO(anyone) add <material> once other PRs are merged -->
-        <min_velocity>10</min_velocity>
-        <max_velocity>20</max_velocity>
-        <color_start>0 0 1</color_start>
-        <color_end>0 1 0</color_end>
-        <scale_rate>10</scale_rate>
-        <color_range_image>/path/to/dummy_image.png</color_range_image>
-        <particle_scatter_ratio>0.01</particle_scatter_ratio>
-      </plugin>
-    </model>
-
-    <!-- test default parameters -->
-    <model name="smoke_generator_demo_model_2">
-      <pose>5 5 0 0 0 0</pose>
-      <static>true</static>
-      <link name="link">
-        <visual name="visual">
-          <geometry>
-            <box>
-              <size>1 1 1</size>
-            </box>
-          </geometry>
-        </visual>
-      </link>
-
-      <plugin filename="ignition-gazebo-particle-emitter-system"
-        name="ignition::gazebo::systems::ParticleEmitter">
-      </plugin>
-    </model>
-  </world>
-</sdf>
-
-

From c4995167b882e51e91d7d0c14da2226c697f9b3b Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:09:33 -0800
Subject: [PATCH 4/8] Moved particle_emitter2 example world and test files to
 particle_emitter

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 examples/worlds/{particle_emitter2.sdf => particle_emitter.sdf} | 0
 test/integration/{particle_emitter2.cc => particle_emitter.cc}  | 0
 test/worlds/{particle_emitter2.sdf => particle_emitter.sdf}     | 0
 3 files changed, 0 insertions(+), 0 deletions(-)
 rename examples/worlds/{particle_emitter2.sdf => particle_emitter.sdf} (100%)
 rename test/integration/{particle_emitter2.cc => particle_emitter.cc} (100%)
 rename test/worlds/{particle_emitter2.sdf => particle_emitter.sdf} (100%)

diff --git a/examples/worlds/particle_emitter2.sdf b/examples/worlds/particle_emitter.sdf
similarity index 100%
rename from examples/worlds/particle_emitter2.sdf
rename to examples/worlds/particle_emitter.sdf
diff --git a/test/integration/particle_emitter2.cc b/test/integration/particle_emitter.cc
similarity index 100%
rename from test/integration/particle_emitter2.cc
rename to test/integration/particle_emitter.cc
diff --git a/test/worlds/particle_emitter2.sdf b/test/worlds/particle_emitter.sdf
similarity index 100%
rename from test/worlds/particle_emitter2.sdf
rename to test/worlds/particle_emitter.sdf

From cc6765190cda4c7ef01756752b971953774feacc Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:12:19 -0800
Subject: [PATCH 5/8] renamed emitter2 to emitter in example world and tests

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 examples/worlds/particle_emitter.sdf |  4 ++--
 test/integration/particle_emitter.cc |  6 +++---
 test/worlds/particle_emitter.sdf     | 10 ++++------
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/examples/worlds/particle_emitter.sdf b/examples/worlds/particle_emitter.sdf
index 8995d3fe464..36fae35919d 100644
--- a/examples/worlds/particle_emitter.sdf
+++ b/examples/worlds/particle_emitter.sdf
@@ -42,8 +42,8 @@
       name="ignition::gazebo::systems::SceneBroadcaster">
     </plugin>
     <plugin
-      filename="ignition-gazebo-particle-emitter2-system"
-      name="ignition::gazebo::systems::ParticleEmitter2">
+      filename="ignition-gazebo-particle-emitter-system"
+      name="ignition::gazebo::systems::ParticleEmitter">
     </plugin>
 
     <light type="directional" name="sun">
diff --git a/test/integration/particle_emitter.cc b/test/integration/particle_emitter.cc
index d8b4922c7bc..24ddbc1c82c 100644
--- a/test/integration/particle_emitter.cc
+++ b/test/integration/particle_emitter.cc
@@ -37,7 +37,7 @@
 using namespace ignition;
 using namespace gazebo;
 
-class ParticleEmitter2Test : public InternalFixture<::testing::Test>
+class ParticleEmitterTest : public InternalFixture<::testing::Test>
 {
   public: void LoadWorld(const std::string &_path, bool _useLevels = false)
   {
@@ -58,12 +58,12 @@ class ParticleEmitter2Test : public InternalFixture<::testing::Test>
 
 /////////////////////////////////////////////////
 // Load an SDF with a particle emitter and verify its properties.
-TEST_F(ParticleEmitter2Test, SDFLoad)
+TEST_F(ParticleEmitterTest, SDFLoad)
 {
   bool updateCustomChecked{false};
   bool updateDefaultChecked{false};
 
-  this->LoadWorld("test/worlds/particle_emitter2.sdf");
+  this->LoadWorld("test/worlds/particle_emitter.sdf");
 
   // Create a system that checks a particle emitter.
   test::Relay testSystem;
diff --git a/test/worlds/particle_emitter.sdf b/test/worlds/particle_emitter.sdf
index 4b32c57574d..9408144425c 100644
--- a/test/worlds/particle_emitter.sdf
+++ b/test/worlds/particle_emitter.sdf
@@ -8,8 +8,8 @@
     </physics>
 
     <plugin
-      filename="ignition-gazebo-particle-emitter2-system"
-      name="ignition::gazebo::systems::ParticleEmitter2">
+      filename="ignition-gazebo-particle-emitter-system"
+      name="ignition::gazebo::systems::ParticleEmitter">
     </plugin>
 
     <light type="directional" name="sun">
@@ -97,11 +97,9 @@
             </box>
           </geometry>
         </visual>
+        <particle_emitter name="smoke_generator" type="point">
+        </particle_emitter>
       </link>
-
-      <plugin filename="ignition-gazebo-particle-emitter-system"
-        name="ignition::gazebo::systems::ParticleEmitter">
-      </plugin>
     </model>
   </world>
 </sdf>

From 3038fe0de95db9f30c3540c8a060822e7cbd671d Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:14:48 -0800
Subject: [PATCH 6/8] Fix integration test

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 test/integration/CMakeLists.txt      |  1 -
 test/integration/particle_emitter.cc | 10 ++++------
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/test/integration/CMakeLists.txt b/test/integration/CMakeLists.txt
index e09452bbad5..d5378a979ad 100644
--- a/test/integration/CMakeLists.txt
+++ b/test/integration/CMakeLists.txt
@@ -42,7 +42,6 @@ set(tests
   network_handshake.cc
   odometry_publisher.cc
   particle_emitter.cc
-  particle_emitter2.cc
   performer_detector.cc
   physics_system.cc
   play_pause.cc
diff --git a/test/integration/particle_emitter.cc b/test/integration/particle_emitter.cc
index 24ddbc1c82c..ada18c5f7b4 100644
--- a/test/integration/particle_emitter.cc
+++ b/test/integration/particle_emitter.cc
@@ -73,7 +73,7 @@ TEST_F(ParticleEmitterTest, SDFLoad)
         _ecm.Each<components::ParticleEmitter,
                   components::Name,
                   components::Pose>(
-            [&](const ignition::gazebo::Entity &_entity,
+            [&](const ignition::gazebo::Entity &,
                 const components::ParticleEmitter *_emitter,
                 const components::Name *_name,
                 const components::Pose *_pose) -> bool
@@ -121,9 +121,7 @@ TEST_F(ParticleEmitterTest, SDFLoad)
               {
                 updateDefaultChecked = true;
 
-                EXPECT_TRUE(_name->Data().find(std::to_string(_entity))
-                    != std::string::npos);
-                EXPECT_EQ(_name->Data(), _emitter->Data().name());
+                EXPECT_EQ("smoke_generator", _name->Data());
                 EXPECT_EQ(msgs::ParticleEmitter_EmitterType_POINT,
                     _emitter->Data().type());
                 EXPECT_EQ(math::Pose3d(0, 0, 0, 0, 0, 0), _pose->Data());
@@ -133,7 +131,7 @@ TEST_F(ParticleEmitterTest, SDFLoad)
                     msgs::Convert(_emitter->Data().size()));
                 EXPECT_DOUBLE_EQ(10.0, _emitter->Data().rate().data());
                 EXPECT_DOUBLE_EQ(0.0, _emitter->Data().duration().data());
-                EXPECT_FALSE(_emitter->Data().emitting().data());
+                EXPECT_TRUE(_emitter->Data().emitting().data());
                 EXPECT_EQ(math::Vector3d(1, 1, 1),
                     msgs::Convert(_emitter->Data().particle_size()));
                 EXPECT_DOUBLE_EQ(5.0, _emitter->Data().lifetime().data());
@@ -144,7 +142,7 @@ TEST_F(ParticleEmitterTest, SDFLoad)
                     msgs::Convert(_emitter->Data().color_start()));
                 EXPECT_EQ(math::Color::White,
                     msgs::Convert(_emitter->Data().color_end()));
-                EXPECT_DOUBLE_EQ(1.0, _emitter->Data().scale_rate().data());
+                EXPECT_DOUBLE_EQ(0.0, _emitter->Data().scale_rate().data());
                 EXPECT_EQ("", _emitter->Data().color_range_image().data());
               }
 

From deaf1b1a7d11721c67b50411a49ee3e31736fa73 Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Wed, 12 Jan 2022 11:23:29 -0800
Subject: [PATCH 7/8] Update tutorial and example world

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 examples/worlds/multi_lrauv_race.sdf | 10 ++--------
 tutorials/particle_tutorial.md       | 10 +++++-----
 2 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/examples/worlds/multi_lrauv_race.sdf b/examples/worlds/multi_lrauv_race.sdf
index 717bf861802..a936210dd97 100644
--- a/examples/worlds/multi_lrauv_race.sdf
+++ b/examples/worlds/multi_lrauv_race.sdf
@@ -38,12 +38,9 @@
       <uniform_fluid_density>1000</uniform_fluid_density>
     </plugin>
 
-    <!-- Requires ParticleEmitter2 in ign-gazebo 4.8.0, which will be copied
-      to ParticleEmitter in Ignition G.
-      See https://github.com/ignitionrobotics/ign-gazebo/pull/730 -->
     <plugin
-      filename="ignition-gazebo-particle-emitter2-system"
-      name="ignition::gazebo::systems::ParticleEmitter2">
+      filename="ignition-gazebo-particle-emitter-system"
+      name="ignition::gazebo::systems::ParticleEmitter">
     </plugin>
 
     <light type="directional" name="sun">
@@ -60,9 +57,6 @@
       <direction>-0.5 0.1 -0.9</direction>
     </light>
 
-    <!-- Requires ParticleEmitter2 in ign-gazebo 4.8.0, which will be copied
-      to ParticleEmitter in Ignition G.
-      See https://github.com/ignitionrobotics/ign-gazebo/pull/730 -->
     <include>
       <pose>-5 0 0 0 0 0</pose>
       <uri>https://fuel.ignitionrobotics.org/1.0/mabel/models/Turquoise turbidity generator</uri>
diff --git a/tutorials/particle_tutorial.md b/tutorials/particle_tutorial.md
index d15049b9fff..dc6ab9f28eb 100644
--- a/tutorials/particle_tutorial.md
+++ b/tutorials/particle_tutorial.md
@@ -4,15 +4,15 @@ This tutorial shows how to use the particle emitter system to add and configure
 
 ## Particle Emitter System
 
-We will demonstrate the particle emitter system by using the [examples/worlds/particle_emitter2.sdf](
-https://github.com/ignitionrobotics/ign-gazebo/blob/ign-gazebo4/examples/worlds/particle_emitter2.sdf) world.
+We will demonstrate the particle emitter system by using the [examples/worlds/particle_emitter.sdf](
+https://github.com/ignitionrobotics/ign-gazebo/blob/main/examples/worlds/particle_emitter.sdf) world.
 
 To be able to spawn particle emitters,  first you will need to include the particle emitter system as a plugin to the world in your SDF. The system does not take any arguments.
 
 ```xml
     <plugin
-      filename="ignition-gazebo-particle-emitter2-system"
-      name="ignition::gazebo::systems::ParticleEmitter2">
+      filename="ignition-gazebo-particle-emitter-system"
+      name="ignition::gazebo::systems::ParticleEmitter">
     </plugin>
 ```
 
@@ -60,7 +60,7 @@ The SDF 1.6+ specification supports having a `<particle_emitter>` SDF element as
 Let's launch the example world to see what it looks like.
 
 ```bash
-ign gazebo -v 4 -r particle_emitter2.sdf
+ign gazebo -v 4 -r particle_emitter.sdf
 ```
 
 You should see the fog slowly starting to appear from the ground plane in the world:

From 9f7648aa3ca5c497045f45d42339e0b0618fe455 Mon Sep 17 00:00:00 2001
From: Nate Koenig <nate@openrobotics.org>
Date: Mon, 14 Feb 2022 09:10:13 -0800
Subject: [PATCH 8/8] Updated migration guide, and deprecated ParticleEmitter2

Signed-off-by: Nate Koenig <nate@openrobotics.org>
---
 Migration.md                                      | 7 +++++++
 src/systems/particle_emitter2/ParticleEmitter2.hh | 5 +++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Migration.md b/Migration.md
index 4fbe67cda46..1bf5bf5286d 100644
--- a/Migration.md
+++ b/Migration.md
@@ -5,6 +5,13 @@ Deprecated code produces compile-time warnings. These warning serve as
 notification to users that their code should be upgraded. The next major
 release will remove the deprecated code.
 
+## Ignition Gazebo 6.x to 7.0 
+
+* **Deprecated**
+  + The `ParticleEmitter2` system was renamed to `ParticleEmitter`. The
+  `ParticleEmitter2` system is now deprecated. Please use the
+  `ParticleEmitter` system. 
+
 ## Ignition Gazebo 6.1 to 6.2
 
 * If no `<namespace>` is given to the `Thruster` plugin, the namespace now
diff --git a/src/systems/particle_emitter2/ParticleEmitter2.hh b/src/systems/particle_emitter2/ParticleEmitter2.hh
index a52d39f65ff..e9dd359d004 100644
--- a/src/systems/particle_emitter2/ParticleEmitter2.hh
+++ b/src/systems/particle_emitter2/ParticleEmitter2.hh
@@ -31,7 +31,8 @@ namespace systems
 {
   class ParticleEmitter2Private;
 
-  /// \brief A system for running and managing particle emitters. A particle
+  /// \brief This is deprecated, please use the ParticleEmitter system.
+  /// A system for running and managing particle emitters. A particle
   /// emitter is defined using the <particle_emitter> SDF element.
   ///
   /// This system will create a transport subscriber for each
@@ -51,7 +52,7 @@ namespace systems
         public ISystemPreUpdate
   {
     /// \brief Constructor
-    public: ParticleEmitter2();
+    public: IGN_DEPRECATED(7) ParticleEmitter2();
 
     // Documentation inherited
     public: void Configure(const Entity &_entity,