Clash Detective - value of distance

[mairh_tsek]

Hello all,

I am trying to understand in the results of Clash Detection what the distance value means, as sometimes the elements are overlapping in another distance that the displayed distance in the results.

Also when I run a Crearance test I get some negative values, why?

[See the attachments]

Thank you in advance!

[Katsubo_IA]

Hello,

"intersection method

A standard Hard clash test type applies a Normal Intersection Method, which sets the clash test to check for intersections between any of the triangles defining the two items being tested (remember all Autodesk Navisworks geometry is composed of triangles). This may miss clashes between items where none of the triangles intersect. For example, two pipes that are exactly parallel and overlap each other slightly at their ends. The pipes intersect, yet none of the triangles that define their geometry do and so this clash would be missed using the standard Hard clash test type. However, choosing Hard (Conservative) reports all pairs of items, which might clash. This may give false positives in the results, but it is a more thorough and safer clash detection method.

severity

For hard clashes, the severity of a clash depends on the intersection of the two items intersecting. Hard clashes are recorded as a negative distance. The more negative the distance, the more severe the clash. Hard clash severity depends on whether the Conservative or Normal Intersection Method has been applied (see intersection method for more details on this). If Normal, the greatest penetration between a pair of triangles is measured. If Conservative, the greatest penetration of space around one item into the space around another is measured.

For clearance clashes, the severity depends on how close one item invades the distance required around the second. For example, an item coming within 3mm is more severe than an item coming within 5mm of the other.

For duplicate clashes, the severity depends on how close one item is to the other. When the distance between them is zero, it is more likely that this is duplicate geometry, where as items that are further apart are more likely to be different objects and therefore have a lesser severity."

Taken from the site Navisworks Help
To see the triangles in the program, change the rendering style to "frame"