Using PCMaster

Tips and Tricks on how to use the software and explanations of what each function does

PCMaster has a very simple user interface with a near zero learning curve. The main window is shown below.

Create Project

The main window shows:

  • Workflow control panel with
    • buttons to perform actions on the current project, creating a new project, opening an existing one, saving it, changing filters and producing LAS files
    • button to toggle display of different path segments on and off
    • button to toggle display of different lasers on and off, and to adjust calibration of each laser
    • buttons to adjust offsets
  • Status bar showing the local plane position of the cursor and the dimensions of the measurement box
  • Main 3D view showing current trajectory, currently enabled path segments and their point clouds from currently enabled lasers, the local plane axes, the cursor focused on the current position and the measurement box if measurements are currently being taken

The main 3D view can be controlled with as few as two mouse buttons, two keyboard keys and the mouse wheel.

To look at the focus from different directions press and hold Left mouse button and move the mouse.

To rotate the camera around its axis, press and hold Shift and Left mouse button and move the mouse.

To move the focus horizontally, press and hold Ctrl and Left mouse button and move the mouse.

To move the focus up and down, press and hold Ctrl, Shift and Left mouse button and move the mouse.

To move the camera closer to the focus, scroll the mouse wheel forward.

To move the camera away from the focus, scroll the mouse wheel back.

To make perspective smaller (telephoto view) press and hold Shift and scroll the mouse wheel forward.

To make perspective wider (wide-angle view) press and hold Shift and scroll the mouse wheel back.

These field of view changes are useful when a long plane is looked at from its side. When the camera is in the telephoto mode, all parts of the plane have the same visible thickness with no perspective. This is very useful for laser calibration and offset adjustment. In this mode trackball rotations are also slowed down for fine adjustments.

Right mouse button – when it is clicked, it opens the context menu with actions:

  • Start, restart, or finish new path segment selection at the point where the mouse is now;
  • Start, restart measurement at the current focus point or stop measurement;
  • Switch point cloud coloring between by-segment and by-laser.

Mouse buttons and wheel work the same way on touchpads, including multi-touch ones with mouse wheel modeled by zoom-in multi-touch pattern.

Workflow Control Panel

Workflow control buttons are:

  • New Project – clears the current data if any and asks for the new trajectory and new scan files. New data are loaded, and the trajectory is displayed. Calibration values and offsets are taken from the ROCK LiDAR scan files; filters are cleared.
  • Open Project – clears the current data and loads the trajectory and the scans from the selected project. The paths and the lasers are selected for display and export as specified in the project. Calibration values, offsets, and filters are loaded from the project file as well.
  • Paths – opens the list of currently selected trajectory segments with their display colors. Each can be checked and unchecked for display and for export, and each can be removed using the Remove action button.
  • Lasers – opens the list of lasers in the scan files and their calibration values. Each can be checked and unchecked for display or export, and each calibration value can be adjusted. Adjusted values are immediately applied to the point clouds in the main view.
  • Linear Offset – opens the panel showing the linear offset of the LiDAR reference point from the IMU reference point in the LiDAR reference frame. The changes immediately apply to the cloud.
  • Angular Offset – opens the panel showing the alignment between the LiDAR and the LiDAR reference frame. The changes immediately apply to the cloud.
  • ROCK LiDAR Orientation – opens the panel showing the ROCK LIDAR orientation in the vehicle reference frame. This should match the orientation entered in the LiDAR settings; it is recorded in the scan files and should not normally be changed unless the orientation was set incorrectly by mistake and had to be corrected in the trajectory generation software.
  • Cloud Filter – opens the panel where filters can be enabled and configured. The filters are discussed in the next section. Changes in the configuration apply immediately to the cloud.
  • Save Project – saves the current state of the project to a project file.
  • Produce LAS – produces the LAS file for every selected path checked for export, using points from every laser checked for export. Points are filtered through currently enabled filters. Project is automatically saved before production. The LAS files are saved in the "clouds" sub-folder in the folder where the project file is saved.

Cloud Filters

Cloud filters allow users to clean up the point cloud by eliminating points produced by reflections and some distortion points caused by high angular rates of the vehicle.

The filters are:

  • Rotation angle filter restricts the cloud to points obtained from lidar when its reported rotation angle is between the minimum and the maximum value. For example, when a UAV flies above the ground, only points from the sector below the UAV make sense. Thus, the range can be limited to some 120-150 degrees around the nadir. If the range around 360 degrees is desired, the left value should be set larger than the right value. That way, the range will be limited from the left value to 360 degrees plus from 0 degrees to the right value.
  • Distance filter restricts the cloud to points within a certain distance range from the LiDAR in meters. This is useful for filtering out reflections from the car roof by setting the left value to some 2 meters and the right to some insanely large value.
  • Reflectivity filter restricts the clouds to points within certain reflectivity range.
  • Angular rate filter restricts the clouds to points taken when the ROCK LiDAR was turning slower than the set value in degrees per second.
  • Easting, Northing, and Altitude filters simply reject points that are outside the set boundaries in meters.