Categories and Elements Feature Overview
The Categories tab in the NextGen viewer groups model elements by their IFC entity type.
Categories exist so you can apply color and transparency to a whole group of elements at once, making it easier to tell element types apart at a glance in the 3D model.
You can also override a category-wide color or transparency setting for an individual element when needed.
Categories are generated automatically from IFC entity data already present in the model, so no manual setup is required.
How It Works
Category-Level and Element-Level Settings
You can apply color and transparency at two levels: the category level, which affects every element that shares that category, and the individual element level, which affects only the selected element.
When both are set, the element-level setting takes priority over the category-level setting. Resetting an element’s override returns it to whatever value is currently set at the category level. For example, if you set a category to green and one of its elements to blue, resetting that element’s color turns it green, matching its category’s color.
Where Category Values Come From
Category values come from the IFC entity data in the model, typically set in a BIM authoring tool such as Revit. These values don’t change based on anything you configure in the viewer.
To change an element’s category or add a new category, update the IFC entity data in the BIM authoring tool and upload a new version of the model. The category values will reflect the new IFC entity data.
Filtering by Active Models
Categories can be filtered to show only models currently open in the viewer, or expanded to show every available category regardless of which models are open.
Permissions and Prerequisites
- Access to the NextGen viewer in the Viewer activity center.
- The model must be uploaded as an IFC file with entity type data intact.
Expected Behaviors
- Color and transparency configurations are session-based. They reset when you exit the activity center, refresh the browser, or reopen the model, unless the configuration is saved as a saved view.
- Color and transparency do not appear in viewpoints in the Issues activity center. Viewpoints open in their default color and transparency settings in model view.
- Certain IFC entities, such as spaces, have a category in the viewer but can’t be colored or have a transparency setting applied.
While a Reader can set and modify category and element colors, they can’t save these configurations as a saved view.