BIM works flows of using Autodesk products, such as Infraworks, Civil 3d, Map 3d, Recap Pro and Navisworks that makes my life easier.

Wednesday, March 19, 2014

Navisworks - Negate Layers

Navisworks has the function to create search set to query your graphical data bases. I've been using Navisworks to perform clashes detection of services vs. a proposed light rail track slab.  The pipe layers have be predefined with the pipe orientation to the track slab . Therefore there would be 3 predefined possibility of  crossing the track slab, parallel to the track slab with in a predefined criteria offset and the third that it falls outside of Crossing or Parallel. Example of such a search would be to find all drainage pipes that are Crossing the track slab.
The search would look like the image below, for drainage find all pipethat are crossing the track slab.
Another search would be a pipe parallel to the track slab with in a predefined criteria offset.  The first two search are simple query because your able to search for  a key  string(Crossing or Parallel)  in the search set.  The third query would be search for every thing that is not Crossing and Parallel. Well this is where there is not a predefined condition of "does not contains"  Crossing and Parallel.
To create a does not contain query you first have to find the elements that you want to filter  out.
Find Item Layer Contains "Crossing"
Find Item Layer Contains "Parallel"
The above to lines need to be Negate Conditions.
Next you still need Navisworks to search for the remaining  items.
  • Find Item  Layer defined
The end result is you now have a does not query.