Modifying the Grow Window

About the Grow Window

The Grow Window parameter is a moving window size used to group points based on the Boundary Trace Class. The moving window will be a square with length and width twice the value. This moving window is fit around an initial point, and a surface growing process occurs grouping points with the same classification and within a distance specified by grow window parameters. The grow window value should approximate the ground sample distance or be slightly larger.

Effects of Increasing or Decreasing the Grow Window

• Increasing Value: Increasing the grow window value above the point spacing could result in grouping adjacent objects into single objects (e.g., adjacent buildings traced into one building).
• Decreasing Value: Decreasing the grow window value below the maximum point spacing could result in splitting of a single object into multiple objects (e.g., a single building into more than one building). There is a trade-off between grouping adjacent objects into one object and splitting one object into multiple objects that is a function of the point density of the point cloud data.

To facilitate the estimation of point spacings, you can use the point lasso or dropper tool . After clicking this button, you will prompted to draw a polygon (i.e., click to define vertices, and double click to complete) over a set of points in the map you wish to calculate a point spacing for. The estimated point spacing will be populated in the grow window, and trace window text boxes.

How to Modify the Grow Window

Grow Window Text Box

1. On the Point Group Tracing and Squaring property page, type a new Grow Window value into the Grow Window Text Box.
2. Press Apply to commit the change.