04. Brief Insight and Control of the Application - VUKOZ-OEL/3d-forest-classic GitHub Wiki

The control toolbars and menus are on the top of the application window. Toolbars are divided into logical sections – project bar with opening, creating new, importing of projects, etc. The next toolbar affects the view of the clouds in the visualization area. Six icons represent six predefined views of displayed clouds. These are followed by two icons representing the change of the view – orthogonal and perspective projection. The tree and crown toolbar serves for displaying computed attributes. There is a list of all clouds imported into the project on the left side of the application. The biggest part of the application win\sdow is the visualization area where selected clouds and tree/crow variables are visualized. There is a status bar where information about selected methods or clouds is displayed. In the right bottom corner is displayed progress bar when some action takes place.

Figure 1: The application window and description of its parts.

Basic control

• Mouse button configuration in the visualization area:
• Left-click: draw to rotate the view
• Middle-click: draw to zoom the view
• Middle rotate: zoom the view
• Right-click: draw to move the view
• Shift + left click: information about trees at the selected point
• Ctrl + left click: clockwise or counter-clockwise rotation

Context menu on cloud list (right-click on cloud name):

• Delete: delete cloud from the project and if needed from the disk
• Color: change the color of a cloud
• Color by field: set the color of points in the cloud by selected field (axis x, y, z, and intensity)
• Point size: change the size of points in the cloud
• All Clouds ON: all clouds in the project are visible
• All clouds OFF: all clouds in the project are invisible

Keyboard

• p, P: switch to a point-based representation
• w, W: switch to a wireframe-based representation (where available)
• s, S: switch to a surface-based representation (where available)
• +/ -: increase/decrease overall point size
• g, G: display scale grid (on/off)
• u, U: display lookup table (on/off)
• r, R: reset the camera
• f, F: focus on the point
• x, X: selection (in selection mode)
• o, O: perspective (on/off) Alt +: show and allow quick access keys in the menu (underlined character)

Tips: Switching between wireframe and point-based representation does not affect the point clouds. The correct values of the scale grid are shown only when the perspective is off. The display lookup table shows values extent and color range if Color by field is used.

Cloud type description

All data imported into the 3D Forest are stored in the PCD file format (binary compressed PointCloudData). PCD file contains coordinates of all points with intensity value. These four variables of the point representation are being used for the moment. Additional information such as color or path to the transformation matrix file can be found in the MyProject.3df file. There are different point cloud representations during 3D Forest data processing:

Base cloud:

Represents raw data imported into the 3D Forest. The data should be preprocessed in some other software (usually provided with the scanner), where cloud fitting and registering are made. The base cloud is not differentiated. It embodies points of all objects such as terrain, vegetation, buildings, etc.

Figure 2: Example of the base cloud before any segmentation – all points contain just X, Y, Z, and intensity values; no objects or surface types are differentiated.

Terrain cloud:

Using Terrain analysis the base cloud can be divided into vegetation and terrain – two main parts of the forest ecosystem. The terrain cloud represents ground surface and can be used for better calculation of tree position or exported into GIS software for detailed (micro)topography analysis.

Figure 3: Visualization of Terrain cloud (brown) and Vegetation cloud (green) after ground/vegetation separation.

Vegetation cloud:

The part of the base cloud which is not terrain is labeled as vegetation. From this point cloud, the individual trees can be segmented automatically or manually selected so to create another cloud type – tree cloud. Tree cloud: This cloud represents a single tree after manual segmentation. Only for tree clouds, it's possible to compute basic tree variables like DBH, height, position, etc.

Figure 4: Visualization of Tree clouds after tree segmentation – individual trees are displayed in different colors.

Other:

Clouds that represent unclassifiable points or points which do not belong to any other cloud type. These clouds can be displayed or used as vegetation for tree selection/segmentation.