As a basis for all Rule sets, the following describes creating a rule for a physical building element. It can be used as a 'one off' in the current session for the current model or project or incorporated into a BIMMeasure template. When the template is subsequently used, the rule can be copied and refined for the specific model / project.
The following descriptions refer to the use of .ifc files, but .dwf / dwfx and dwg files can also be used.
Note: .ifc files generally have a much greater range of BIM data to choose from.
Creating a rule involves the following steps:
1. Reset the session and create a new rule.
2. Specify the rule selection criteria.
3. Enter the properties to measure.
4. Save the rule and close the session
The following example considers a situation where the BIM Property data related to columns does not appear to have a property that can be used to measure the height of columns. There are no BaseQuantities in this particular ifc file.
Carrying out an initial review of the BIM Properties and associated data is strongly recommended in order to familiarise yourself with the information contained with the model.
Common Properties to all columns
The only common measurement value is Volume.
In checking through the Property Data for each of the column types it appears that there is height data for some column types, but not others.
Dimension Properties for column type H1C11_500x1300mm
For the H1C11_500x1300mm columns there is no height property.
Dimension Properties for column type H1C13 (700x1400)
For the H1C13 (700x1400) columns there is a Height Property called "_ACM_L" (which also applies to other column type in this particular model).
Rule Creation - Rule Name
Select the rule set, right-click and select New Rule.
In the tree node, edit default text with a Rule Name and add a description in the Details tab.
Rule Creation - Selection Criteria
The Selection Criteria is how the BIM Data is searched to create a selection set of BIM objects that are to be measured.
Expand Selection Criteria to display the selection criteria options.
Search Property
Click the Search Property entry to list drop-down list of all the properties that can be searched to create the selection set of objects to measure.
Multiple search properties can be entered if required. Start with the most specific properties and increase the generalisation with other properties if required
Having selected a search property, the condition will be automatically inserted.
Search Value
By clicking on the Search Value drop-down list, a list of all the possible values matching the search property. Select the one required to search on.
Multi Search Criteria
Click + to expand and enter further search criteria using the and/or option. i.e., add where the all the search criteria have to be met or, OR where items matching different criteria will be returned in the selection set. Enter more search criteria as required.
Note: Each criteria is displayed, in full, on the row above the search definitions for the criteria.
Rule Creation - Measurement Properties
For the measurement type to be measured click the appropriate label of Area, Length or Volume to display the Property definition options.
Based on the initial review of the BIM Properties that was carried out, select the Property from the drop down list from which the measured value is to be taken.
In the Property Set row select the Property Set Name in which the required Property can be found. Usually there should only be one option here unless the Property occurs in multiple Property Sets.
Note that the combination of Property Set and Property name for the Measurement Type is shown in first row of the definition options.
In this example the previously identified Property "_ACM_L" in the "Dimensions" Property Set is known to provide the height (i.e. the measured length) of the columns. Similarly the Volume Property in the Dimension is defined to get the Volume measurement value.
Measuring with Rules
If dragging and dropping from the Model Contents tree without a Rule being in place, the system would return a Length value of 0.000m
Drag and drop without a rule in place: Dragging and dropping with a Rule in place will return the value of the Next Measurement Type selected, if the object selected meet the Selection Criteria.
Drag and drop with rule in place: In the above screen shot the Selection Criteria for column type H1C11_500x1300mm did not meet the rule criteria and therefore returned a measured length value of 0.000m for measurement number 2.
However, for column type H1C13 (700x1400) the rule criteria was met and a length measurement value of 56.550m was returned for measurement number 3.