Volume Between Surfaces

You need to create at least two point cloud projects.

Steps

1. Select the Volume Between Surfacesbutton in Tools page, Open the Volume Between Surfaces dialog box.

Parameter dialog box

Parameter setting

• Data Setting: Select the pre-phase and post-phase data
  • Before Source: The pre-phase data at the same location serves as the baseline data.
  • After Source: The post-phase data at the same location.
  • Exchange: Quickly swap pre-phase and post-phase data.
• Region Settings: Methods for creating regions
  • Create Regions: Manually select points in the point cloud using the left mouse button to generate a polygonal region
  • Select Regions: Manually select an existing polygonal region
  • Read from Files: Load polygon vector regions from SHP or DXF vector files
  • All Points: Use the bounding box of all points in the point cloud as the region
• Cell Setting: Use a uniform grid for volume measurement. Here, you can configure the grid cell settings.

Data example.

• Empty Cells: Data often contains voids, which can result in empty cells in the grid. Here, you can configure how to handle these empty cells.

  Volume calculations are performed only within grid cells where both pre-phase and post-phase data are present. No calculations are performed in cells lacking data from either phase. Please configure empty cell handling accordingly based on the actual data.

  • Leave Empty: No action is taken for empty cells.
  • Interpolation: Perform triangular mesh interpolation on both pre-phase and post-phase data separately to fill in all data voids.
  • Mininum Height: Calculate the maximum and minimum heights of the data separately and write the empty cell locations into the minimum height.
  • Maxinum Height: Calculate the maximum and minimum heights of the data separately and write the empty cell locations into the maximum height.
  • Average Height: Calculate the maximum and minimum heights of the data separately and write the empty cell locations into the average height.
  • Usr Defined: After selecting this option, the pre-phase Z and post-phase Z buttons below become active, allowing you to set the Z-values for empty cell locations separately.

• Before Z, After Z: Combine with user-defined options for empty cells.

• Cell Size: Set the size of individual grid cells.

  The default is 0.1, and it should be set based on the point density of the point cloud data. It is recommended to use the default value. If the point density is low, you can consider increasing it accordingly.

  A larger size leads to faster calculations and coarser results, while a smaller size results in slower calculations but relatively more accurate results. However, setting a size smaller than the point spacing can lead to loss of accuracy, so it's not recommended to set it too small.

• Cell Height: Set the basis for cell height calculation.

  • Maxinum Height: Use the highest Z-value from the point set that falls within the current cell as the cell height. (Default)
  • Mininum Height: Use the lowest Z-value from the point set that falls within the current cell as the cell height.
  • Average Height: Use the average Z-value from the point set that falls within the current cell as the cell height.

• Polygon Select: Define the calculation region by manually creating a polygon area.

• All Points: Define the calculation region by using the entire data area. (Default, suitable for scenarios with relatively small data volumes)

• Project Area:

  • Befor, After: Display the calculated projection areas for both pre-phase and post-phase separately.

• Surface Area:

  • Befor, After: Display the calculated surface areas for both pre-phase and post-phase separately.

• Cut: Display the calculated fill volume

At the same cell location, if the height of the post-phase data in that cell is lower than the height of the pre-phase data in the same cell, it's considered as excavation or cut volume.

• Fill: Display the calculated fill volume.

At the same cell location, if the height of the post-phase data in that cell is higher than the height of the pre-phase data in the same cell, it's considered as fill volume.

• Compute All: After setting the parameters, click the calculate button with the mouse to start the calculation of all regions.
• Clear: Clear the result display box.
• Cancel: Exit the function.
• Export: The report export function is not available by default. It becomes available only after completing a calculation without making any parameter changes.

2.Following the manual provided above, configure the parameters, and then click 'Compute All'.

Example of the results

Example of the results

Excavation is displayed in blue, fill is displayed in red, and green represents no change between pre-phase and post-phase data.

Report

1.Click the Export button to open the report information settings interface

Report Setting Dialog

Parameter setting

• Descriptive Information: The text content information of the report.
• Measurement Information: You can set the density to calculate the mass of cut and fill, as well as the total change in mass.

Report example