Short Answer
In almost all cases the cause lies in the IFC structure, not in vyzn. vyzn processes the model via Deep Model Processing (DMP) and recognizes building elements by their IFC type and nesting. If elements are stored incorrectly in the IFC, they are not recognized as separate model elements and can then neither be grouped nor assigned a material.
Issue Description
After importing an IFC model, individual building elements (for example stairs or slabs) do not appear as separate model elements. As a result, you cannot assign them to a group or a material.
Signs of This Issue
- Expected building elements such as stairs or slabs are missing from the list of model elements.
- Several building elements are shown merged as a single element.
- The affected elements cannot be selected, grouped or assigned a material.
Root Cause
- Incorrect nesting in the IFC: The element is attached to the wrong parent type in the IFC. Example: stairs stored under a generic element type (IfcBuildingElementPart) instead of the stair type (IfcStair).
- Stored under a site element: Building elements (for example sloped slabs created with another tool) are stored in the IFC under a single site element (IfcSite, often named «Terrain»). IfcSite is treated as surroundings and ignored in the calculation, so the elements stored within it are not processed as model elements.
Step-by-Step Solution
- In your authoring tool (for example Archicad or Revit), check that the affected element is exported with the correct IFC type (for example IfcStair for stairs).
- Export the model again with the corrected structure.
- If a correction in the authoring tool is not possible, contact vyzn Support (support@vyzn.tech). We correct the model and re-import it into your variant via «Replay», so that your existing groups and material assignments are preserved.
Common Mistakes
- The element is exported from the authoring tool without the proper IFC type or as pure geometry.
- Building elements are stored under a site element (IfcSite) instead of under the building or storey.
If the Problem Persists
Send us the IFC file or the link to the variant. We check the structure, correct the model and re-import it via «Replay». vyzn also continuously extends Deep Model Processing, so that such IFC structures will be recognized automatically in the future.