The base points (control points) allow you to use a coordinate system based on the civil origin or other coordinate system for interoperability and collaboration. For example, you can use base points when inserting reference models, exporting IFC models, in drawings, in Layout manager , and in reports and templates.

Civil origin is the datum point or fundamental benchmark point of the national land survey network.

When you use base points, you can keep the coordinates small and locate the model wherever needed. You can create as many base points as you need, and select one of those to be the project base point.

1. Open a Tekla Structures.
2. Click File > Project properties > Base points to open the Base point dialog box.
3. Fill in the needed information:

   

   Name , Description	Enter a name and a description for the base point.
   Coordinate System	Enter the name of the coordinate system you are using.
   East coordinate (E)	Enter the East coordinate (E) that represents the X coordinate related to the civil origin.
   North coordinate (N)	Enter the North coordinate (N) that represents the Y coordinate related to the civil origin.
   Elevation	Enter the Elevation that represents the Z coordinate related to the civil origin.
   Latitude , Longitude	Enter the Latitude and Longitude of the base point to be used in the IFC export. Latitude and Longitude is additional information, which some software can use. In the IFC file, this is written to IFCSITE information. If the total number of digits in Longitude is more than 15, the value is rounded up to the nearest if it is > 99.999999999999999999. To convert Latitude and Longitude information between decimal format and degree/minute/second (DMS) format, see Convert Latitude/Longitude to decimal.
   Location in the model	Pick or enter a location for the base point in the Tekla Structures model. The distance is measured from the model origin. The location needs to be near the model origin, preferably less than 1000 m from the origin.
   Angle to North	Pick or enter the Angle to North , which is the angle between Y and North directions. The maximum number of decimals for the angle is 13.
   Project base point	If you want to set a coordinate system as the project base point, select a base point from the list at the top and then select the Project base point check box.

4. Click Modify to save the base point.

   A blue symbol is added in the model.

   If you later on make changes to the base point, the base point location in the model changes according to the location or rotation changes you make in the Base point dialog box when you press Enter or click another input field, and there is no need to click Modify.

   

   Now you can insert a reference model, or export an IFC model using the defined base point.

One base point can be set to be as the project base point. Model origin is the default project base point value if the model does not contain any base points, or if none of the existing base points has been set to be the project base point. You can check and change the current project base point through File > Project properties > Location by.

1. Click File > Project properties.

   You can see the current project base point in the Location by box.

2. To change the project base point, click Edit , and select a new project base point from the Location by list.
3. Click Apply.

1. Open the Reference Models list by clicking the Reference Models button in the side pane.
2. In the Reference Models list, click the Add model button.
3. In the Add model dialog box, if you have any previously created reference model properties files, load the desired file by selecting the file from the properties file list at the top.
4. Browse for the reference model by clicking Browse....
5. In Group , select a group for the reference model, or enter a name for a new group.

   If you do not enter a name for the group, the reference model is inserted in the Default group.

6. In Location by , select the base point you want to use.
7. Click the Add model button. Tekla Structures inserts the reference model relative to the selected base point by using the coordinate system values, elevation and angle in the base point definition in the model Project properties.

1. Click File > Export > IFC to open the Export to IFC dialog box.
2. In Location by , select a base point that you have created.
3. Fill in other necessary IFC export information.
4. Click Export. The base point option exports the IFC model relative to the base point using the coordinate system values, elevation, latitude, longitude and angle in the base point definition in the model Project properties.

It is possible to use base-point-defined coordinate system values in drawings. If you change the project base point Z or the elevation value, the level value will change accordingly when a drawing is opened.

1. In an open drawing, double-click the drawing view frame to open the View Properties dialog box.
2. On the Attributes 2 tab, set Location by to a new base point, or to the model origin.
3. Click Modify.

You can use base points in Layout manager when defining the location of layout points.

• You can use base points as location coordinates when exporting and importing layout points.

• When you add, modify or delete base points, you need to reopen or refresh Layout manager to make the changed base point data available in Layout manager.

You can inquire project base point and current base point value in reports and templates.