Make Grid

Use this function for the following:

Run the function from:

MOUS_ICO Menu: Terrain > Volume Calculations > Make Grid

MOUS_ICO Toolbar: Volume Calculation: Make Grid

MOUS_ICO Menu: Novapoint > Terrain Model > Grid Model

MOUS_ICO Toolbar: Terrain Model: Grid Model

When this function is activated, Command prompts for:

First corner for DTM View:

MOUS_ICO Pick the lower left corner for the boundary of the data, for which grid model is to be generated.

To generate the grid model, the area, for which the grid model is to be generated, must be defined. A grid model can be generated for the entire data (all groups) available in the database.

Command prompts for:

Other corner for DTM View:

MOUS_ICO Pick the upper right corner for the boundary of the data, for which grid model is to be generated.

Correct corners can be selected if the data, for which grid model is to be generated, is available on the current drawing. Desired data (available in the database) can be drawn to the current drawing using the function 'Draw Map from Terrain Model' of the menu Novapoint Map. Command prompts for:

Draw frame (Yes/No) <No>:

A frame can be drawn to the current drawing to represent the DTM view with the option 'Yes'.

The lower left and upper right corners of the DTM view can also be defined in the dialog box 'Grid Model', which will pop up in this function.

The dialog 'Create Grid Surface Model' will pop up.

Grid Model from Current Terrain Model

Generate a grid surface model

Use these steps to generate a grid surface model from the data active in the current terrain model.


All active groups (layers) are calculated at the same time and stored in the same grid file. All calculated levels are physically put one after another in the grid file.


Border Coordinates

An area of terrain data in the database must be indicated for which grid model is to be generated (when a new grid file is established).

When supplementing i.e. grid file the sections will be locked to the values of the grid file.


Starts grid generation. The program will first generate grids along the x-axis and then along the y-axis. Grid generation can take some time if there is a large amount of data (large terrain models or small grid size). The program will advise of the number of grid squares and which level is being calculated.

Boundary lines in grid model

Using boundary lines to create holes in the grid model - only grid outside of boundary line (s):

You can use more the one boundary line, but the following must be defined:

The boundary line can be created using either the create line (Define as Boundary line) function in View / Edit or by creating a polyline in AutoCAD and using the function 'Save Boundary Line to Terrain Model'.

Using boundary line to limit the grid model - only grid inside of boundary line


Interpolation Method

For grid modeling, either the point grid (P) OR terrain line (L) method must be selected. If one Level is to be grid modeled on point grid and another on lines, this may be carried out in two stages. The methods cannot be mixed within one and the same Level.

Figure: Method L. Points 1 to 7 are interpolated heights in terrain lines. Points Z1 to Z4 are calculated heights based on grid intersections.

In method L, intersections are sought between terrain lines in both X and Y directions. The height of grid intersections is found by weighting the interpolated terrain line heights with the inverse distance from the grid intersection, e.g. Z3 (1,4), Z2 (5,6,7), Z1 (1,2,3,4). If only one (Z4) or no terrain lines coincide(s), the height will remain undefined.

Figure: Method P. Points 1 to 5 are survey points, Points Z1 to Z3 are calculated grid heights.

In method P, the calculation is done in 2 phases. In the first phase, all points nearer the grid intersection than the grid size are weighted with the inverse distance to the grid intersection. There is no limit on the number of points being used, but there must be at least one. Point Z3 will therefore not be assigned a height in the first phase.

In phase 2, lines between two neighboring grid intersections with heights calculated from phase 1 are considered to be terrain lines. The same technique as in method T is used on these “terrain lines”, in this way “islands” of non-defined grid points will later be assigned a calculated height.

Grid Model from Laser Scan Data

The method of this function: Laser scanned data in XYZ format (text file with Northing, Easting, and Elevation coordinates) or Binary LAS - the format is analyzed, converted, and saved as grid files.

Other Terrain Model functions that can use the Laser Scan data

The 'View/Edit' function can be used to view the grid boundaries. Use this link for an example.

To generate a grid surface model from Laser Scan Data, run the function 'Grid Model', select 'Laser Scan Data' as source data on the dialog 'Create Grid Surface Model', and confirm the selection with 'OK'. A new dialog 'Create Grid Surface Model' will pop up.

Data format

Laser scan data available in the ASCII format or in the Binary LAS format can be selected source data for generating the grid surface model. Select the suitable format.

Default values

The default values for grid size, group number of the boundary line of each grid file being saved to the active terrain model, and feature code of boundary line being saved to the active terrain model are to be defined here. The same values will be displayed in the main dialog and can be changed if necessary.

Confirm the details defined in the above dialog using 'OK' to select the source data files. The dialog 'Open' will pop up, select the format at the field 'Files of Type', browse the source file location, select the source file(s) and confirm the selection using 'Open'. Multiple files can be selected using 'Control' and/or 'Shift' keys. The dialog 'Create Grid Surface model' will pop up.


Use this option to simplify the process of defining the parameters in the main dialog. The dialog 'Dialog' will pop up with the button 'Autofill' or the shortcut menu option 'Autofill'. In this dialog, one can automatically fill the grid size, feature code, and group number.


Use the button in this column to start the analysis. The analysis will be done based on the specified grid size. After the analysis is complete the analysis result will be displayed in a log file (Analysis.LOG). Use this link to view an example.

The information here is mainly a status of the source file analyzed with Filename, the extent of coordinates X, Y, and Z as well as grid size and the number of points in the file.

The connection between grid cells with > 1 point and empty grid cells

Experience from projects using this method indicates that Grid cells with > 1 point should be 10-15%. At the same time, the value of empty grid cells should not exceed 50-60%. This means that several grid sizes are to be analyzed to find the optimal grid size.


Use the button of this column for a preview of the contents of the grid file.



Use this button to start generating the grid files. The status will be displayed in the dialog 'Calculation'.

Mark the check box 'Launch Report' and click 'OK' to obtain the log file (as shown below) and exit the function. Use this link to view the dialog 'Calculation' and the log file of generation grid files.


The 'View/Edit' function can be used to view the grid boundaries. Use this link for an example. Use the shortcut menu option 'Object report' on this boundary line to obtain a report on the grid data within the boundary line.