Objects in IFC have GUIDs (Global Unique Identifier). This is a unique identifier of the object. Whenever a new object is created in the model author tool, it will get a unique identifier, which is also exported to IFC. The same applies in Simplebim.
Let's say you have a dataflow, that splits objects or creates derived objects. Whenever an object is split or a derived object is created, the new object will get a unique identifier. This is all fine. However, what happens when you get a model update and run your dataflow again? The objects are split again, or derived objects are created again, and by default, they will get a new unique identifier. Not the same one as on the previous run.
This might not be a problem if you don't use the unique identifier in your downstream solutions. But if you do, then you need to make sure that the GUIDs stay the same from one model update to another.
This is where the GUID mapping comes in. It makes sure that every time you split an object or recreate a derived object, the new objects will get the same unique identifiers as the previous time.
The process is relatively straightforward. You can include it in your dataflows, so it is done automatically every time. The first time you run your dataflow, a guid map is created. Every time after that, the GUIDs are read from the map, instead of regenerating them from scratch.
To make this work, there needs to be a logic to identify the new objects as being the same as the previous time. When splitting objects, this is usually done based on a combination of the parent object's GUID (the original object that is split) and the identifier of the location where the split object is assigned to.
When creating derived objects, for example, based on the quantities, then the mapping can be done based on the combination of the parent object's GUID and an identifier you assign to the derived objects.
Settings
Objects
Select Object Class, Group, Group Category, Top Most, or Part-level objects. The GUIDs are processed for the objects you set here.
Guid Map File Full Name
The name and location (full path) of the file where the GUID map is stored.
If the file doesn't yet exist, it is created. This will happen the first time you run your dataflow. If the file already exists, then the guids are read from it, and possible new mappings are added. This also means that you don't have to create a new guid map file for each data processing operation you run. However, it is recommended to have one file per model, instead of sharing the mappings between different models from different disciplines or even models from different projects.
PropertySet Name
The property set name of the mapping property.
Mapping Property
The mapping property's value is used together with the parent GUID to find the matching objects for finding and setting the GUID. Note that the system handles the parent GUID in the back ground.
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Comments
5 comments
Hello and thank you! 🙂
I need to know whether installing the Prototype Add-on is necessary. Do we need the “Write GUID Map File (new – to be used with the Split Geometries tool)” feature in order to use GUID mapping?
Hello, thank you for the question!
Which version of Simplebim are you using?
The new Map Guids tool is included in the basic installation package of Simplebim 11. So, you don't have to install the Prototypes addon for that. Note however that the new tool is only available for Simplebim 11, not the earlier versions.
The new Split Objects tool (introduced in Simplebim 11) does not have guid mapping build in, like the old version did. So, yes in order to use Guid mapping with the Split Objects in Simplebim 11 you need to use the Map Guids tool.
Thanks!
Hello again, and thank you!
OK, your answer is clear to me now. So, in Version 11 there is the Map GUIDs feature, and I don’t need the Prototypes add-on anymore.
However, as you can see in the picture below, I’m not getting the Map GUIDs Report in the folder. I’d like to know if there is any other step in between that I might be missing.
First, I imported my prisms, then I split the objects, and then I ran Map GUIDs. You can also see the settings I’m using for Map GUIDs in the screenshot. If I’m missing something which is obvious from pictures, please let me know here. Otherwise, I can send an email to the support team and explain my issue there in more detail 🙂
Hello,
Do you mean that the mapping file is not created?
The dataflow looks correct. Have you checked that the Location property was created to the My Property Set after running the Split Objects tool?
Thanks again, please let us know, if you have any further question! It would great, if you can send more details to the support team.
Hello Sakari,
Thank you again! Yes, I checked and saw that in the setting it was set to Location instead of Basic. After correcting it, I was also able to generate the .mpf file. Thank you! 😊
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