topic Re: problems with Intersect Method (Face) in Revit API Forum

problems with Intersect Method (Face)

pmcmm1 — Wed, 28 Aug 2019 10:07:38 GMT

Hello everyone,

I'm running into some problems with the function Intersection Method. I'm using revit's energy model to find adjacencies between envelope elements. Therefore I am getting the geometry of each envelope element, passing it to faces and then running intersection between all of them. So far, so good.

The problem comes when I started to analyze the results, the function kept returning more intersections than expected, sometimes even repeated ones. This is strange as the energy model consists of good geometry. So I started to analyze the results surface by surface, and I found the culprit. For two surfaces totally separated, sometimes the function returned an adjacency. See the picture as an example in which a face from a wall and a face from a floor returned an adjacency (in blue):

I went to revitapidocs and I might have found why this happens:

"Face class => Face Methods => Intersection Method (Face)

Remarks:

This is not a general-purpose function: it only works properly for simple configurations. For other configurations, it may return an incorrect result."

Does this mean that this function is unreliable? In which situations are not working? Is my request too complex for this function?

Thanks for the help,

Pedro

Re: problems with Intersect Method (Face)

Revitalizer — Wed, 28 Aug 2019 10:44:34 GMT

Hi,

old bug...

https://forums.autodesk.com/t5/revit-api-forum/surprising-results-from-face-intersect-face-method/m-p/8079881

https://forums.autodesk.com/t5/revit-api-forum/face-class-intersect-method-problem/m-p/7460467

Revitalizer

Re: problems with Intersect Method (Face)

pmcmm1 — Wed, 28 Aug 2019 12:22:44 GMT

Thanks for the prompt reply Revitalizer!

I find it very disappointing that the error has been reported more than two years ago and autodesk has neither fixed it or nor updated the revit documentation informing that this function often provides false positives...

Re: problems with Intersect Method (Face)

Revitalizer — Wed, 28 Aug 2019 12:28:52 GMT

Hi,

me, too.

It's much easier for the company to add new features than to fix the old bugs.

Prodly presenting new stuff in shorter intervals...

https://blogs.autodesk.com/revit/2019/08/23/revit-public-roadmap-august-2019/

Revitalizer