Modify albedo map with a plugin. What am I missing?

1

I would like to implement a plugin that switches back and forth between two albedo map files. In addition, I am closely following the command actor plugin tutorial from the repository (gz-sim/examples/plugin/command_actor/CommandActor.cc at gz-sim8 · gazebosim/gz-sim · GitHub)

// SatelliteGround.hh

namespace ros_gz_example_gazebo
{
  class SatelliteGround:
    public gz::sim::System,
    public gz::sim::ISystemConfigure,
    public gz::sim::ISystemPreUpdate
  {
    public:
      void Configure(
        const gz::sim::Entity &_entity,
        const std::shared_ptr<const sdf::Element> &_sdf,
        gz::sim::EntityComponentManager &_ecm,
        gz::sim::EventManager &_eventManager
      ) override;
      
      void PreUpdate(
        const gz::sim::UpdateInfo &_info,
        gz::sim::EntityComponentManager &_ecm
      ) override;

    private:
      gz::sim::Entity entity;
      gz::sim::Entity visualEntity{gz::sim::kNullEntity};
      gz::common::Timer timer;
      bool toggle{false};
      std::chrono::steady_clock::time_point lastUpdateTime;
      const std::chrono::seconds updateInterval{2};

      std::string texture1{"materials/textures/charuco_board_pattern.png"};
      std::string texture2{"materials/textures/circles_pattern.png"};
  };

}

// SatelliteGround.cc

#include <iostream>
#include <gz/plugin/Register.hh>
#include <gz/sim/components/Material.hh>
#include <gz/sim/components/Name.hh>
#include <gz/sim/EntityComponentManager.hh>
#include <gz/sim/EventManager.hh>
#include <gz/sim/System.hh>
#include <gz/rendering/RenderingIface.hh>
#include <gz/rendering/RenderEngine.hh>
#include <gz/sim/rendering/Events.hh>
#include <sdf/Pbr.hh>
#include <gz/rendering/Material.hh>
#include <gz/rendering/RenderTypes.hh>
#include "ros_gz_example_gazebo/SatelliteGround.hh"

using namespace ros_gz_example_gazebo;

void SatelliteGround::Configure(
    const gz::sim::Entity &_entity,
    const std::shared_ptr<const sdf::Element> &_sdf,
    gz::sim::EntityComponentManager &_ecm,
    gz::sim::EventManager &_eventManager
)
{
    std::cout << "ros_gz_example_gazebo::SatelliteGround::Configure on entity: " << _entity << std::endl;

    this->entity = _entity;
    // Find the visual entity by its name
    this->visualEntity = _ecm.EntityByComponents(
        gz::sim::components::Name("ground_plane_visual"));

    if (this->visualEntity == gz::sim::kNullEntity)
    {
        std::cerr << "Error: Visual entity not found." << std::endl;
        return;
    }

    // Initialize the last update time
    this->lastUpdateTime = std::chrono::steady_clock::now();
}

void SatelliteGround::PreUpdate(
    const gz::sim::UpdateInfo &_info,
    gz::sim::EntityComponentManager &_ecm)
{
    auto currentTime = std::chrono::steady_clock::now();
    if (currentTime - this->lastUpdateTime >= this->updateInterval)
    {
        // Retrieve the material component
        auto materialComp = _ecm.Component<gz::sim::components::Material>(this->visualEntity);

        if (!materialComp)
        {
            std::cerr << "Error: Material component not found." << std::endl;
            return;
        }

        sdf::Material newMaterial;
        sdf::Pbr pbr;
        sdf::PbrWorkflow pbrWorkflow;

        std::string texturePath;
        if (this->toggle)
        {
            texturePath = this->texture1;
        }
        else
        {
            texturePath = this->texture2;
        }
        pbrWorkflow.SetAlbedoMap(texturePath);
        pbrWorkflow.SetRoughness(0.6);
        pbrWorkflow.SetMetalness(0.0);
        pbr.SetWorkflow(sdf::PbrWorkflowType::METAL, pbrWorkflow);
        

        newMaterial.SetAmbient(gz::math::Color(0.8, 0.8, 0.8, 1));
        newMaterial.SetDiffuse(gz::math::Color(0.8, 0.8, 0.8, 1));
        newMaterial.SetSpecular(gz::math::Color(0.8, 0.8, 0.8, 1));
        newMaterial.SetPbrMaterial(pbr);

        *materialComp = gz::sim::components::Material(newMaterial);

        _ecm.SetChanged(
            this->entity,
            gz::sim::components::Material::typeId,
            gz::sim::ComponentState::OneTimeChange
        );

        this->lastUpdateTime = currentTime;
    }
}

GZ_ADD_PLUGIN(
    ros_gz_example_gazebo::SatelliteGround,
    gz::sim::System,
    ros_gz_example_gazebo::SatelliteGround::ISystemConfigure,
    ros_gz_example_gazebo::SatelliteGround::ISystemPreUpdate
)

It compiles and runs but the changes are not reflected visually on the simulation. What am I missing?

2

Hello @soutvie,
Did you found a solution?

3

Yes I did! Would you like to hop on a call so I explain you? Send me a PM if interested