Familie Performance
Families have an impact on three different kinds of performance in Revit that you need to consider. Every modeling decision revolves around performance, functionality, and the ability to achieve an intended BIM use.
The three types of performance are:
- Load Performance
- View Regeneration Performance
- Editing Performance
Category
Categories are useful for organizing and sorting families in the DAQS Assist.
Instances
The number of times a family type is placed in the Revit model determines whether it’s worth investing effort into optimizing it. High instance counts typically have a greater impact on performance.
Faces
The number of faces in a family is a key indicator of whether it warrants further investigation, especially when combined with the number of solids. A high face count doesn’t necessarily mean a poorly designed family, but it increases the likelihood of finding areas for optimization.
Solids
Similar to faces, the number of solids in a family can indicate potential optimization opportunities. While a high solid count doesn’t inherently mean a family is inefficient, it’s worth reviewing such families for possible improvements.
Graphic Styles / Subcategories
If a solid lacks a subcategory, it doesn’t directly affect performance, but it limits control over what is displayed in a view. Properly assigned subcategories can significantly enhance performance by enabling finer control over visibility settings.
GS N
GS N represents the number of solids without a graphic style (subcategory). Ideally, this should be zero, and the assigned graphic styles should comply with company or country standards.
GS Y
GS Y represents the number of solids with a graphic style (subcategory). Ideally, this should match the total number of solids, with all graphic styles adhering to relevant standards.
Visibility
Not 4
The number of solids not visible at all four detail levels. A higher number is preferable, provided it’s done correctly.
Is 4
The number of solids visible at all four detail levels. A lower number is preferable, provided it’s done correctly.
Detail Level Recommendations
Coarse
Minimize the geometry displayed at the coarse detail level to maximize performance. Show only the essential elements.
Medium
The medium detail level should vary by category but typically include only practical, simplified 3D solids.
Fine
Use the fine detail level to display solids necessary to convey detailed design intent. Remember, you’re communicating design intent, not creating a video game.
TAX
TAX is a simplified metric to help identify families with the most significant potential for performance improvements. It’s calculated as:
TAX = Number of Faces × Number of Instances
A higher TAX value indicates families where optimization efforts could yield the greatest benefit to view performance.
DAQS Assist Column headers
| Column header | Explanation |
|---|---|
| Type | Family Type |
| Category | Revit Category |
| Inst. | # of Instances |
| Faces | # of Faces of all Solids |
| Solids | # of Solids |
| Sub no | # of Solids without a sub-category |
| Sub yes | # of Solids with a sub-category |
| Not 4 | # of Solids NOT visible on all 4 detail levels |
| Is 4 | # of Solids visible on all 4 detail levels |
| U | # of Solids visibility undefined |
| C | # of Solids visible on Coarse detail level |
| M | # of Solids visible on Medium detail level |
| F | # of Solids visible on Fine detail level |
| TAX | # of instances * # of faces to give a impact value |