Trimble Connect Product Update

New Clash Detection Engine

What’s New

We have now deployed a renewed version of the Trimble Connect cloud based clash detection engine. The new clash detection engine is based on new algorithms and new technologies and it targets to generate more meaningful and accurate results. The Trimble Connect for Windows and the Trimble Connect for Browser 3D Viewer applications start automatically using the new clash check engine. 

Differences Compared to the Previous BSQ Clash Detection and Known Limitations

1. The model file names in the clash set must contain only upper- and lower-case English alphabets and numbers (a - z, A-Z, 0-9)
2. The clash detection engine supports a limited number of geometry types. Currently, it supports only polygonal geometries (more specifically: faceted brep geometry representation). Clashes and clearances between other geometry representations will not be detected. Typical examples of 3D model content that uses non-supported geometry types are: road alignments and surfaces, pipe networks and rebars.  Clashes or clearances between these types of 3D model content will not be detected.
3. Rebars are not handled (clashes or clearances are not considered at all with rebars). This is the same in the previous BSQ-based clash detection. This is a known limitation resulting from the limited geometry type support.
4. The “distance” that is calculated in case of clashes by the TrimBIM engine reflects a different concept compared to the “distance” calculated by the BSQ engine.
   
   
   1. In case of the TrimBIM engine the calculated clash “distance” is the penetration depth, defined as “how much the two geometries have to be moved apart from each other so that they don’t intersect anymore”:
      
      
   2. In case of the BSQ engine the calculated clash “distance” is the length of the shortest intersection edge:
      
      
      
      Note that the “distance” calculated in case of clearances is the same in case of the TrimBIM and BSQ engines and it is the distance between the closest pair of points of the two geometries.
5. The clash geometries (intersection lines) are different when generated by the TrimBIM engine and when generated by the BSQ engine.
   
   
   1. The TrimBIM engine only generates intersection lines which are inside faces (inner intersection):
      
      
   2. The BSQ engine also generates intersection lines which are on the edges of faces (inner intersection + touching intersection):
      
      
   3. TRB:
      
      
   4. BSQ:
      
      
6. Touching geometries (which do not penetrate each other, but also have no distance between them, they touch exactly at 0 distance) are not detected as clashes by the TrimBIM engine but are detected as clashes by the BSQ engine. Both engines can detect them as clearances, though, with 0 distance.
   
   
   1. TRB:
      
   2. BSQ:
      
7. In the edge case when a model is split up and saved into multiple “sub-models” and some entities are accidentally saved into more than just one “sub-model” and a clash-detection is performed between these “sub-models” (in other words in the case when the detection is run against models which contain entities with identical GUIDs), the BSQ clash detection finds clashes between the entities with identical GUID, the TrimBIM clash detection does not (so clashes between the element and itself will not be detected by the TrimBIM clash detection). This is an edge case because in normal circumstances the clash set should never include entities with identical ID. However, one possible scenario where this could happen is running a clash check between the same model’s two different versions but this has not been identified as a valid scenario.
8. The BSQ clash detection and TrimBIM clash detection algorithms work with different distance tolerances. Clashes between geometries which barely penetrate each other (somewhere between 1/1000 mm and and 1/10 mm) are detected by the BSQ clash detection, but not by the TrimBIM clash detection. The TrimBIM variant will only find clashes which have a “noticeable” penetration depth (at least 1/10 mm).
9. The TrimBIM clash detection returns a clean result list, where each result (clash between the same entity pair) is only present once. This is different compared to the previous BSQ clash detection where the same result could be listed multiple times.
10. The TrimBIM clash detection does not detect when one geometry is completely inside the other. The algorithm classifies such cases as clearances instead of as clashes because there is no actual intersection on polygon level and polygon-level intersections are what the algorithm is looking for.
    
11. When the clashing geometries are complex, the TrimBIM clash detection engine is sometimes unable to calculate the max penetration depth (“distance”). In this case the UI will display 0 as the distance value.