topic Line.Intersection gives incorrect Result? in Revit API Forum

Line.Intersection gives incorrect Result?

Spyrite — Wed, 02 Jun 2021 08:51:25 GMT

Greetings!

Why when I try to find intersection between (for example) Line.CreateBound(XYZ(0,0,0), XYZ(100,0,0)) and Line.CreateBound(XYZ(25,0,0), XYZ(75,0,0))
I've got SetComparisonResult.Equal instead of SetComparisonResult.SubSet or SetComparisonResult.SuperSet?

Thank's.

Re: Line.Intersection gives incorrect Result?

RPTHOMAS108 — Wed, 02 Jun 2021 11:24:53 GMT

By description your arrangement of lines doesn't match any of the conditions noted since Subset and Superset mention one of the two curves being unbound.

Subset: unbound curve passed are argument

Superset: unbound curve used to invoke check

So perhaps they check the parameters of curve 'A' between its limits against those of curve 'B' and find it is equal without considering the limits of curve 'B' match (they only check for unbound status).

Then again I struggle to understand how parallel lines can have one common intersection (as noted by Subset). Perhaps they are parallel lines joined at ends only? These are the problems with descriptions, always open to interpretation.

Re: Line.Intersection gives incorrect Result?

Spyrite — Wed, 02 Jun 2021 12:07:36 GMT

Thank's for your answer!

By the way, I've found that intersection between (this is an example) Line.CreateBound(XYZ(0,0,0), XYZ(10,0,0)) and Line.CrateBound(XYZ(0,0,0), XYZ(-10,0,0)) gives right Subset result, so it's actual even for two bound curves.

Perhaps, "parallel lines" mentioned in API discription means a common case, including that case when distance between those parallel lines is equal to zero. It's really hard to understand...