qt_pi/gazebo_sim/models/path/materials/scripts/path.material

    material path/Image
    {
      technique
      {
        pass
        {
          ambient 0.5 0.5 0.5 1.0
          diffuse 1.0 1.0 1.0 1.0
          specular 0.0 0.0 0.0 1.0 0.5
          texture_unit
          {
            texture path.png
          }
        }
      }
    }