Volume Computation with BuildIT Construction

Tutorial Download

If you would like to download the file used in this article, download the accompanying Training Data and extract its contents to a folder on your PC.

Create a Reference Plane

Open the “Module 10 - volume analysis.buildit” file by selecting “File> Open” and navigating to where the file is saved.

• The command to calculate volume needs a plane of reference first. This plane can either be fit to the point cloud, or created based on a specified elevation. For this exercise, one will be created based on a specified elevation. There is a control point in the file to use as the base elevation.
  • Select “Construct > Plane”.
  • Name the plane “Reference Plane”.
  • For “Center”, use the “Point: Nominal” filter to select the control point.
  • For “Normal”, select Z. This will make the plane perfectly upright at the elevation we chose.
  • Enter values of 2500 inches for “Length” and 1600 for “Width”. This will make the plane visually larger and easier to select, as well as expand the analysis area.
  • Select Apply.
    

Cut and Fill Volume Analysis

• Now, the analysis will be performed.
  • Select “Evaluate > Cut and Fill Volume Analysis”.
  • Select the Cloud.
  • Select the “Reference Plane”.
  • Enter 0 for "Tolerance threshold"
    • The tolerance threshold represents a certain distance above or below the reference plane to ignore. For instance, entering 0.25 inch would represent a small area above or below the reference plane where the volume would not be calculated.
  • Specify a zone size. Use 4 inches for this exercise.
    • The zone size is the sampling distance on a grid for the analysis.
  • Select Cell average for "Height Evaluation".
    • Cell average will create an average reference point from all the points in a cell..
    • Low/High Point will create a point from the highest or lowest deviation from reference to represent the cell.
    • Center Point will create a point from the point closest to the middle of the cell.
  • Check “Detect walls”.
    • This feature detects a high distribution of points, indicating a wall or column and ignores those cells for the area and volume computation. It will also exclude those cells when interpolating values for adjacent cells with no measurements or identified debris. Wall height is the distance from the plane that it uses to detect walls, so for areas with lower partitions, a lower number is required.
  • Check “Clean up debris”.
    • This will use a few parameters to decide whether a cell has debris. If it is marked as debris, the cells around it will be used to interpolate a value for the analysis.
      • Clean-up height: If there are any points above this height in a cell, they are marked as debris.
  • Note: Units will be in cubic yards when imperial units are detected as user units. Units will be liters or cubic meters otherwise.
    
  • Select Apply.
  • Check the messages for area and volume calculations.