Model Compare performs model comparison audit on geometry and/or properties. This tool can determine if an object has changed based on a nominated identifier.
Model Compare reads the geometry from 2 models and compares the models for differences. Objects are categorized into 4 sets:
- Matching – the object geometry is identical (Yellow)
- New – the items are in the second model, not the first (Cyan)
- Deleted – items in the first model which have no possible matches in the second (Red)
- Unmatched – items in the first model that have one or more possible matches (other items with the same centroid) but which after comparing have no exact matches (Magenta)
- Changed – if ‘Detect Changes Based on Unique Id’ is ticked, objects from New, Deleted and Unmatched that share the unique id will be moved into this set.
There are a few options for model comparison; the algorithm is biased towards false negatives rather than false positives, so objects that appear the same may be categorized as unmatched. This can be fine-tuned using the options. Due to the nature of floating-point operations, this is something than can be limited but not eradicated. The results should be interpreted accordingly.
