Base points

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.

Note the following:

Reference models should not have any additional lines to the origin.
Reference models should not include objects that are very far from each other because otherwise using the model may get difficult.
Tekla Structures native objects, including reference models, should not be inserted very far from the Tekla Structures model origin.

Define a base point

You can define base points in Project properties. In case you need to import or export a reference model, you need to know the coordinates of the reference model that you are importing, or the coordinates that you want to use in the resulting IFC export file.

Tip: You can inquire the point coordinates in Tekla Structures: On the ribbon, click the down arrow next to

, and then select Point coordinates. For more information, see Inquire object properties.

Open a Tekla Structures.
Click File > Project properties > Base points to open the Base point dialog.

Fill in the needed information:

You can load existing base point settings. To do this, copy your settings file <settings name>.basePoint.json from the \attributes folder under the model where you have the base point settings you want to use to the \attributes folder under the current model folder. In the Base point dialog, select the base point settings from the list.

Note that base point settings also work with project and firm folders: Copy the base point settings file to the \attributes folder under the firm and project folders.


Name, Description	Enter a name and a description for the base point. Giving a name is obligatory.
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. The Z value of the project base point coordinates sums with the Elevation value defined separately.
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 base point location in the model can have a maximum value of +/- 10 km from the model origin. Modeling is meant to be done near the model origin, and the offset is to be given with East coordinate and North coordinate values.
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 checkbox.

To save the base point settings, type a unique name for the settings and click Save.
To use the same base point settings in another model, copy your settings file <settings name>.basePoint.json from the \attributes folder under the current model folder to the \attributes folder under the model where you wish to use the same base point settings. The settings also work with project and firm folders: Copy the base point settings file to the \attributes folder under the firm and project folders.
To avoid unwanted changes by others working in the same model, lock the base point by clicking the Lock/Unlock button next to the base point name.
The button changes to . To unlock the base point, click the button again.
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 when you press Enter or click another input field, and there is no need to click Modify. Note that if the base point is locked, you cannot modify it.

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

Set a coordinate system as the project 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.

Do not change the project base point during a project.

Click File > Project properties.

You can see the current base point in the Location by box.
To select the project base point, click the Base points button, select a base point from the Location by list, and then select the Project base point checkbox.
Click Modify.

Insert a reference model using a base point

Before you can insert a reference at the base points, you need to create a base point in your model. To create the base point, you need to know the coordinates of the reference model that you are importing.

Open the Reference models list by clicking the Reference models button in the side pane .
In the Reference models list, click the Add model button.
In the Add model dialog, 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.
Browse for the reference model by clicking Browse....
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.
In Location by, select the base point you want to use.
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. For example, both IFC2x3 and IFC4 reference model inserting support base points.

Export an IFC model using a base point

Before you can export an IFC file using a base point, you need to create a base point in your model.

Click File > Export > IFC to open the Export to IFC dialog.
In Location by, select a base point that you have created.
Fill in other necessary IFC export information.
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.

Base points in drawings

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.

Base point data can be used on the drawing and drawing view level to set the coordinate system. The base point can be used instead of the datum offset.
When the base point is set, level attributes and template attributes in marks provide values in the specific base-point-defined coordinate system. Attributes with _BASEPOINT at the end give coordinates relative to the base point that has been selected in the view, and attributes with _PROJECT at the end give coordinates relative to the base point selected as the project base point.
When the base point is set at the drawing level, the _BASEPOINT template attributes can be used in drawing templates.

In the drawing view properties, you can set Location by to model origin, project base point, or any base point defined coordinate system. Location by uses the project base point as the default value.

If you have not set Location by to any base point, the _BASEPOINT attributes give the same result as the basic attributes. For example, COG_Z would give same result as COG_Z_BASEPOINT. However, COG_Z_PROJECT always gives the value according to the project base point.

The datum level in the view properties only affects the attributes TOP_LEVEL and TOP_LEVEL_UNFORMATTED when Location by is set to Model origin or to the project base point that is in the model origin.

To change the Location by value:

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

Example of base point usage in a drawing

In the following example, do the following:

Create a slab with a thickness of 200 mm with the slab's top at the level 0 in the model.
Create a new base point "Control point 1" with elevation 20000 mm.
Create a new base point "Project point 1" with elevation 10000 mm, and set is as project base point by selecting the Project base point checkbox.
Create a GA drawing in plan view.
Open the GA drawing, double-click the view frame to open the View Properties dialog.
On the Attributes 2 tab, set Location by to the new base point Project base point: Project point 1 and click Modify.
Add a level mark using the following template attributes:
- COG_Z
- COG_Z_PROJECT
- COG_Z_BASEPOINT
Reopen the drawing.

Note that changing the value does not update the template attribute automatically but after reopening the drawing.

Base points in Layout manager

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.

Base point in reports and templates

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

The following table lists the template attributes where you can use _PROJECT and _BASEPOINT at the end, for example, ASSEMBLY_BOTTOM_LEVEL_PROJECT or ASSEMBLY_BOTTOM_LEVEL_BASEPOINT. Attributes with _BASEPOINT at the end give coordinates relative to the base point selected in the view, and attributes with _PROJECT at the end give coordinates relative to the base point selected as the project base point. _BASEPOINT uses the current base point in the same way as the work plane uses the current work plane: If there is no current base point defined, _BASEPOINT provides values relative to model origin (Global).


Content type	Attributes
`ASSEMBLY`, `CAST_UNIT` and `PART`	ASSEMBLY_BOTTOM_LEVEL ASSEMBLY_BOTTOM_LEVEL_UNFORMATTED ASSEMBLY_TOP_LEVEL ASSEMBLY_TOP_LEVEL_UNFORMATTED BOTTOM_LEVEL BOTTOM_LEVEL_UNFORMATTED BOUNDING_BOX_MIN_X BOUNDING_BOX_MIN_Y BOUNDING_BOX_MIN_Z BOUNDING_BOX_MAX_X BOUNDING_BOX_MAX_Y BOUNDING_BOX_MAX_Z BOUNDING_BOX_X BOUNDING_BOX_Y BOUNDING_BOX_Z COG_X COG_Y COG_Z START_X START_Y START_Z END_X END_Y END_Z TOP_LEVEL TOP_LEVEL_UNFORMATTED `LOCATION_BREAKDOWN_STRUCTURE.LBS_FLOOR_ELEVATION` `ASSEMBLY.LOCATION_BREAKDOWN_STRUCTURE.LBS_FLOOR_ELEVATION`
`REFERENCE MODEL`, `REFERENCE OBJECT` and `REFERENCE_ ASSEMBLY`	BOUNDING_BOX_MIN_X BOUNDING_BOX_MIN_Y BOUNDING_BOX_MIN_Z BOUNDING_BOX_MAX_X BOUNDING_BOX_MAX_Y BOUNDING_BOX_MAX_Z `LOCATION_BREAKDOWN_STRUCTURE.LBS_FLOOR_ELEVATION`
`POUR OBJECT`	BOTTOM_LEVEL BOTTOM_LEVEL_UNFORMATTED TOP_LEVEL TOP_LEVEL_UNFORMATTED `LOCATION_BREAKDOWN_STRUCTURE.LBS_FLOOR_ELEVATION`
`CONNECTION`	ORIGIN_X ORIGIN_Y ORIGIN_Z
`HIERARCHIC OBJECT`	`LOCATION_BREAKDOWN_STRUCTURE.LBS_FLOOR_ELEVATION`