Create iterator for custom height field in pointcloud.

nav2_collision_monitor/include/nav2_collision_monitor/pointcloud.hpp

@@ -113,6 +113,10 @@ class PointCloud : public Source
   double min_height_, max_height_;
   // Minimum range from sensor origin to filter out close points
   double min_range_;
+  /**Changes height check from "z" field to "height" field for pipelines utilizing
+   * ground contouring
+   */
+  bool use_global_height_;
 
   /// @brief Latest data obtained from pointcloud
   sensor_msgs::msg::PointCloud2::ConstSharedPtr data_;

nav2_collision_monitor/params/collision_detector_params.yaml

@@ -26,4 +26,5 @@ collision_detector:
       transport_type: "raw" # Options: raw, zlib, draco, zstd
       min_height: 0.1
       max_height: 0.5
+      use_global_height: False
       enabled: True

nav2_collision_monitor/params/collision_monitor_params.yaml

@@ -100,4 +100,5 @@ collision_monitor:
       transport_type: "raw" # Options: raw, zlib, draco, zstd
       min_height: 0.1
       max_height: 0.5
+      use_global_height: False
       enabled: True

nav2_collision_monitor/src/pointcloud.cpp

@@ -106,21 +106,43 @@ bool PointCloud::getData(
   sensor_msgs::PointCloud2ConstIterator<float> iter_y(*data_, "y");
   sensor_msgs::PointCloud2ConstIterator<float> iter_z(*data_, "z");
 
+  bool height_present = false;
+  for(const auto & field : data_->fields) {
+    if (field.name == "height") {
+      height_present = true;
+    }
+  }
+
+// Reference height field
+  std::string height_field{"z"};
+  if (use_global_height_ && height_present) {
+    height_field = "height";
+  } else if (use_global_height_) {
+    RCLCPP_ERROR(logger_, "[%s]: 'use_global_height' parameter true but height field not in cloud",
+    source_name_.c_str());
+    return false;
+  }
+  sensor_msgs::PointCloud2ConstIterator<float> iter_height(*data_, height_field);
+
   // Refill data array with PointCloud points in base frame
   for (; iter_x != iter_x.end(); ++iter_x, ++iter_y, ++iter_z) {
     // Transform point coordinates from source frame -> to base frame
     tf2::Vector3 p_v3_s(*iter_x, *iter_y, *iter_z);
 
+    double data_height = *iter_z;
+    if (use_global_height_) {
+      data_height = *iter_height;
+      ++iter_height;
+    }
+
     // Check range from sensor origin before transformation
     double range = p_v3_s.length();
     if (range < min_range_) {
       continue;
     }
-
     tf2::Vector3 p_v3_b = tf_transform * p_v3_s;
-
     // Refill data array
-    if (p_v3_b.z() >= min_height_ && p_v3_b.z() <= max_height_) {
+    if (data_height >= min_height_ && data_height <= max_height_) {
       data.push_back({p_v3_b.x(), p_v3_b.y()});
     }
   }
@@ -148,6 +170,9 @@ void PointCloud::getParameters(std::string & source_topic)
   nav2::declare_parameter_if_not_declared(
     node, source_name_ + ".transport_type", rclcpp::ParameterValue(std::string("raw")));
   transport_type_ = node->get_parameter(source_name_ + ".transport_type").as_string();
+  nav2::declare_parameter_if_not_declared(
+    node, source_name_ + ".use_global_height", rclcpp::ParameterValue(false));
+  use_global_height_ = node->get_parameter(source_name_ + ".use_global_height").as_bool();
 }
 
 void PointCloud::dataCallback(sensor_msgs::msg::PointCloud2::ConstSharedPtr msg)
@@ -178,6 +203,8 @@ PointCloud::dynamicParametersCallback(
     } else if (param_type == rcl_interfaces::msg::ParameterType::PARAMETER_BOOL) {
       if (param_name == source_name_ + "." + "enabled") {
         enabled_ = parameter.as_bool();
+      } else if (param_name == source_name_ + "." + "use_global_height") {
+        use_global_height_ = parameter.as_bool();
       }
     }
   }