Load PCD

To first load up one of the car’s recorded pcd files, you will want to create a new point processor, similar to the one we created before in the simpleHighway function. This time however you will be using the pcl PointXYZI type, the "I" stands for intensity, which will now be an additional feature for each point in the cloud.
In environment.cpp you should create a new function called CityBlock that will be the same layout as the simpleHighway function. The arguments for CityBlock will be the same as simpleHighway , a reference to the pcl viewer.
Inside the new CityBlock function you will create a new point processor using a PointXYZI template argument. You will use the point processor to load one of the car’s point clouds and then use the renderPointCloud function to view it. Don't forget to call cityBlock now instead of simpleHighway in the main function. Check out the code below for reference.
All of the car’s pcd files are located in src/sensors/data/pcd/data_1/

void cityBlock(pcl::visualization::PCLVisualizer::Ptr& viewer)
{
  // ----------------------------------------------------
  // -----Open 3D viewer and display City Block     -----
  // ----------------------------------------------------

  ProcessPointClouds<pcl::PointXYZI>* pointProcessorI = new ProcessPointClouds<pcl::PointXYZI>();
  pcl::PointCloud<pcl::PointXYZI>::Ptr inputCloud = pointProcessorI->loadPcd("../src/sensors/data/pcd/data_1/0000000000.pcd");
  renderPointCloud(viewer,inputCloud,"inputCloud");
}

The image below is what the results of loading and running this look like, if the color is not specified in the renderPointCloud function argument, it will default to using the intensity color coding.
Looking around the pcd, you can see several cars parked along the sides of the road and a truck approaching to pass the ego car on the left side. Your goal will be to fit bounding boxes around these cars and the passing truck, so then your system could later use that information in its path planner, trying to avoid any collisions with those obstacles.

Instructions

• Create cityBlock function as shown above
• Replace the simpleHighway call in main with cityBlock
• Compile/Run, The output will look like the image above
• Orbit and Zoom around the point cloud