Define a comparison set for reference model change detection
Change detection in Tekla Structures compares different versions of the reference modelmodel which the designer can use as an aid when building another model
A reference model is created in Tekla Structures or in other software and can be inserted to Tekla Structures. The reference model appears together with the model but it is not modified by Tekla Structures. The user can snap to reference model points.
For example, an architectural model, a plant design model, or a heating, ventilating, and air-conditioning (HVAC) model can be a reference model.
based on a comparison setset of object properties that are used for detecting changes in reference models
Tekla Structures compares different versions of the reference model based on a comparison set, which tells if a change in a property is considered a change.
, which tells you whether Tekla Structures considers a change in a property a change or not. You can use the standard property comparison set, or define a comparison set of your own.
In the reference model, when change detection is active, the changes list shows all deleted, changed, new and not changed objects. The property details list only contains those properties that are defined by the current comparison set rules to be compared.
When you save a comparison file, both the standard file and a customized comparison set file are saved to the \attributes folder under model folderfolder that is used for storing files associated with a model
Tekla Structures stores all files associated with a model in a folder it creates with the same name as the model database (.db1).
In multi-user mode all users access the same model folder.
. The standard file can only be removed from model folder if it exists in another location. If saving or removing the standard fileproperty file that Tekla Structures uses by default
Standard file name is standard.* where the symbol * is the file name extension. For example, standard.clm file is used for column properties and standard.clm.more file is used for column user-defined attributes.
is not successful, you will get an error message.
Create a new comparison set
- Open two versions of the same reference model.
- In Change detection, click the Comparison sets button ... to open the Comparison sets dialog box.
- Enter a name for the comparison set.
- Add a new comparison rule by clicking the Add row button and typing or copying and pasting the property name.
- You can copy and paste property names directly from the property details list in change detection.
To include more properties within one rule, use asterisk (*), for example:
X* (all that starts with X)
*X (all that ends with X)
- If you want to compare only one property set property, clear the Property sets check box and create a separate rule for that property. If you want to compare all property sets but not one property, select the Property sets check box and create rule for that property and leave its check box empty.
- Note that comparison rules are case insensitive.
All rules in comparison set affect the comparison if the reference model version has a corresponding property.
- Add more rules in the same way as in step 2 and 3.
- To delete a rule, select the rule and click the Delete row button . You cannot delete fixed comparison rules, like Geometry, Location, Rotation, Materials, Profiles, Products, Common attributes or Property sets, but you can exclude those from comparison by leaving the check boxes next to them empty.
- Ensure that you have the check box selected next to all the comparison rules you want to include in the comparison set. If you do not want to include a rule, clear the check box. Tip:
You can also exclude attributes already included in a property set by adding a separate row for that specific attribute and then ensuring that you do not add a check mark in the check box next to that specific attribute.
- Click the Save button .
- Close the comparison set dialog box by clicking the Close button . If you have not saved your changes, you will be asked if you want to keep the changes when you close the dialog box.
- Click the Update view button.
Properties in comparison property set
- Free property set properties, such as BaseQuantities.NetVolume
- Fixed properties that always exist in the comparison set file, but can be excluded from the comparison
The fixed properties are listed below:
|Location||The coordinates of the object in the model|
|Rotation||The rotation coordinates of the object|
|Material||Material name and grade|
IfcProduct parameters that vary object type by type. Some properties are optional.
Below examples of product properties for IfcColumn:
Application full name
Is set last modified date
Last modified date
Below examples of common attributes for IfcColumn:
Whatever has been added to IFC properties.
Below examples of property set properties for IfcColumn:
Tekla Common.Bottom elevation
Tekla Common.Preliminary mark
Tekla Common.Top elevation
Tekla Quantity.Area per tons [m²]
Tekla Quantity.Gross footprint area [m²]
Tekla Quantity.Height [mm]
Tekla Quantity.Length [mm]
Tekla Quantity.Net surface area [m²]
Tekla Quantity.Weight [kg]
Tekla Quantity.Width [mm]
Tekla Quantity.Volume [mm³]
Define property comparison tolerances
In reference model version comparison, you can modify the property comparison tolerance settings to get relevant changes more easily. You need two versions from the same IFCfile format commonly used in BIM that facilitates software interoperability
IFC is an open specification developed by the IAI (International Alliance for Interoperability).
Model can be exported into an IFC file.
The changed row appears as light yellow if the tolerance is bigger than the difference.
- Open two versions of the same reference model.
- In the Reference Models pane, open the Change detection section and activate the change detection.
- Click the Property set comparison tolerances button .
- Change the tolerances by modifying the values.
- Apply the changes by closing the dialog box and clicking Update view.
The changed row appears as light yellow.
You can also save the tolerances in the Property set comparison tolerances dialog box.