IFC Import Options
Explains IFC Import options when using IFC Import function
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Explains IFC Import options when using IFC Import function
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Import options update frequently as the tools are developed and improved. If there is an option that is not explained below, please please email support or post a query on the forum.
There a number of options which can be specified when importing or opening a IFC file. The below shows the options with explanations on each.
The co-ordinate reference allows the model to be imported into Revit with a transfomation relative to the Revit base point or origin.
Project: By selecting Project the IFC building or model will be inserted in relation to the Project base point in Revit. This is the default selection, but should only be used when only local coordinates are used in model placement in IFC.
Shared: If shared co-ordinates have been established in Revit, then this can be specified as the point for insertion of the model. The IFC model will be transformed relative from IFC placement to the project base point. Note the IFC placement can deviate from shared coordinates point.
When you are using the ImportIFC function (as opposed to the OpenIFC function), you will need to have your shared co-ordinate defined (this should include angle for true north) in Revit prior to importing or else you are likely to get import errors with elements being to far away from the origin.
When you nominate import on the basis of shared coordinates, the IFC model is transformed from it's own remote coordinates relative to the shared coordinate position.
Relative: Using the relative setting will import the IFC model into Revit relative to the Revit Origin.
The importer provides the ability to automatically create Revit Parameters that are defined in the IFC file being imported.
When checked/ticked (✔) the project parameters that are defined in the IFC file and not defined in Revit will be created as project parameter. The plug-in will also automatically search for existing project parameters prior to creating any new ones. If and existing parameter is found than the value will be updated as per the imported file. This is the default option.
If not checked/ticked new project parameters will not be created and only existing ones will be set from IFC data.
When checked/ticked (✔) Existing building Revit stories with the same Name as stories within the IFC file will be modified based on the elevation defined in the IFC, provided they differ if they differ.
You may want the Revit model levels to be the master of level height definitions. therefore, if you do not want the levels to update when importing uncheck this option.
The Source Mark option allows you to choose which IFC parameter you will use to define the Revit element Mark from. You can select the IFC object Name, Tag or choose to adopt none and leave this blank.
filter options allow for only specific items from an IFC model file to be imported into Revit. This give greater control for user where they have been provides a big model and only require some portion of that model for the import.
The inclusion option allows you to specify which IfcClasses are to be included in the Import. You can select multiple categories by comma delineation. i.e:
IfcBeam, IfcMember, IfcWindow
The inclusion option allows you to specify which IfcClasses are to be excluded in the Import. You can select multiple categories by comma delineation. eg:
IfcSpace, IfcFurnishingElement, IfcFastener, IfcMechanicalFastener
If the IFC global id is not consistent when importing revisions of the same model (i.e the authoring application is changing id values) the geometry gym importer provides some further options to update members as defined in the options below.
By using these options elements will be updated (rather than being replaced with updated information).
The deviation option allows the importer to search for members within a specified proximity of an existing member to select elements for update. Proximity should be defined in mm.
Revision Id Parameters
The parameter option allows you to set and search another unique parameter to search for a member update. You can also prescribe multiple parameters which need to be satisfied for the update.
For example: TeklaIDtag; Level
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When importing Revit framing elements you can allow Revit to automatically cutback framing families when joined to adjacent elements.
A framing family has two reference planes at each end, permitting members (say steel) to have an offset/cutback of the extrusion from the endpoint. This is on the family, not the instance.
Native modelling in Revit will try to automatically join framing elements together. This importer setting can prevent Revit from automatically joining structural framing elements. The default is ticked.
The coarse profile setting uses a beam section polyline with a coarse representation of aspects such as fillets on beams. this was more important in the early days of Revit (and computers) where resources for processing and graphics were limited.
If you are using your own reference framing families this setting will not be taken into account.
The importer will automatically build a Revit analytical model for defined structural elements if present in the IFC file. You can prevent analytic bys by checking/ticking (✔) this option.
Family precut is an Autodesk Revit parameter which has to do with the 2D representation of elements. Geometry Gym allow you to set this parameter on framing elements from our import. You can read more about this parameter here:
Degrees from Vertical to enforce Column:
Degrees from vertical to enforce IFC member elements to be defined as Revit column elements rather than framing elements. The default is 10 degrees.
Ignore Member Axis:
Advanced feature to allow importer to ignore the member axis in IFC to define framing axis. It will be computed from the extrusion when this option is checked/ticked. Rarely will a user require this option.
The ****Space**** import option allows you to choose how to import IfcSpaces into the Revit project. You select to bring spaces in as Rooms, Space, Room Boundary, Space Boundary or ignore spaces by selecting None.
Walls Bound Rooms
Setting ****the Revit wall parameter for wall bounding or not. When checked/ticked (✔) this will be set true for all imported walls. ****
Enable Wall Joins
When modelling in Revit, it will automatically attempt to join wall elements together. This importer settings allows the user to restricts Revit from automatically joining wall elements on import. The default is checked/ticked (✔).
The geometric representation of a site within an IFC file can be brought into Revit as either as a topography element, or as direct shape. You also have the option to select none which will ignore any geometric site representation within the IFC model being imported.
The generate shafts option provides an option to automatically generate Revit shaft elements within floor and wall elements or whether to define openings as simple floor void openings. When checked Revit shafts are created when an opening is present within a slab or wall in the imported IFC model. If the item is unchecked a simple floor or wall void opening will be created within the element.
The IFC importer allows for you to map specific IFC class items to Revit Category's. This is explained more here:
Update Existing Family Symbols:
Revise existing family types that have been or are modified in the IFC model to be imported. You may want the Revit model to be the master of families and you just want to update the instances. This is typically the case therefore the default is unchecked.
Create Assemblies
You can create Revit groups from defined IFC Assemblies by enabling the create assemblies option. By default, this is checked/ticked (✔).
Disable existing elements update/replace/removal
You can manually manage existing element updates independently of the update element options above. If this item is ticked click this item it will create a duplicate (not remove or check to update any of the existing elements). The detection of previous import (or existing element) is determined by the IFC GlobalId.
This is generally a last resort option to the other import options available above as it can be time consuming and provides room for error by duplicating Revit elements.
Prioritize Parametric over precision
Some IFC models will utilize parametric geometry that is not compatible with Revit. If this option is not checked/ticked, the importer may revert to a direct shape if it encounters an error and parametric is not preferred over precision.
Use Direct Shapes
Direct shapes are objects that the user can not edit within Revit, for reference only. They may generally be more accurate for complex geometry. It is the default that complex shapes are inserted as direct shapes. If this item unchecked the importer will attempt to create shapes which are editable within Revit (but the import process will take longer). Resultant revit file size may be larger for direct shape dominant models.
Direct Shape Material from Styling
IFC geometry can be associated with a style to nominate surface coloring, transparency etc which displayed in a viewer. If this option is ticked, the direct shape will be associated with a material representing the style, rather than a semantic material association (ie concrete, steel etc).
Native Structural Elements
If the importer is not generating accurate and precise native structural elements, you can force the use of direct shapes by checking/ticking this option. Particularly where advanced construction solid geometry is nominated for advanced steel detailing.
Purge Ineffective Cuts
Some IFC exports have clipping cuts (ie mitres or member shortening) nominated that do not intersect with the extrusion body. This option will instruct the importer to remove ineffective cuts when detected (else an orphaned cut persists in Revit).
Remove degenerate edges/faces
Revit has a short line limit, of about 0.7mm. Any mesh edge shorter than this (or coincident points within this tolerance) will generate a direct shape that will not display. If you are observing missing tessellated/meshed elements after import, toggle this setting on. Detection process of short edges (and coincident points) will slow down the import significantly to detect this, particularly on models with large face count tessellations (ie terrain models particularly on infrastructure models).
Explode CAD to Freeform:
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Delete SAT/DWG Files defining Type Geometry:
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Deviation tolerance for smoothing FacetedBreps
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Angle (degrees) threshold to mask faceted crease edges
Removing crease edges from a Revit model by allowing a deviation or setting an angle face deviation to mask edges. This provides a more desirable looking 3d model when importing complex faceted geometric object.
