curve intersect result

[sfaust]

I'm trying to compare a set of walls to see what level of intersection they have (if any). To test, I just have file with 4 walls in a square. The following code is run after adding each wall to a set called "WallSet" and copying it to "wset2". So essentially I'm comparing each wall to every wall in the project right now (including itself) so I would expect to get 4 "equal" and the rest "disjoint" or maybe "overlap". However, I am getting all 16 comparisons coming back as "equal". What am I missing about how this method works?

 
For Each w As Wall In WallSet
     Dim cv As LocationCurve = w.Location
     For Each w2 As Wall In wset2
          Dim cv2 As LocationCurve = w2.Location
          Dim r As Autodesk.Revit.Enums.SetComparisonResult = cv.Curve.Intersect(cv.Curve)
          MsgBox(w.Name.ToString & " & " & w2.Name.ToString & ": " & r.ToString)
     Next
Next

[sfaust]

ugh, how about I intersect two DIFFERENT walls, instead of the same one, of course it's equal... Always the small dumb stuff...

[sfaust]

ok, I have another question that hopefully isn't quite as dumb...

How would you go about checking two walls between levels? Basically I want to check if two walls are exactly on top of each other. I can check when they are on the same level by the above (getting the curve and doing an intersect).

However, if they are on different levels the the curves do not intersect. So what I would like to do is just take the curves, clone them, and set the z coordinate on the clones to 0, then run an intersect. I can't find a way to change the curves once I have them, though.

Can anyone help?

[david.bartliff]

I think what you need to do is
clone the points for the location curves (XYZ)
change the Z values of the points
create new curves from the points
Sorry - not got time to write the actual code

[sfaust]

I think what you need to do is
clone the points for the location curves (XYZ)
change the Z values of the points
create new curves from the points
Sorry - not got time to write the actual code

no problem, direction is good. I was able to get the points and 0 out the z cooridinate, but for the life of me I can't figure out how to create a curve from the new points. I can also clone the existing curve and use the 'set_endparameter' method, but that asks for index which is the which end point (fine) and parameter as double... I can't figure out what the end parameter is, and if I try putting 0 in it just gives me an error. When I try to dim a new curve it just says that curve is set to MustInherit so it can't use New. So how do I construct a new curve from the points?

thanks for any help...

[david.bartliff]

Look at NewLinebound and NewArc under Autodesk.Revit.Creation.Application
i.e. something like rvtApp.Create.NewLineBound( pointA, pointB);

I cant remember exactly what the parameters are for - is it something like 0.0 is the start and 1.0 is the end, so if you change the end to 3.0 the line will be extended in the same direction so its 3 times longer?

[sfaust]

you rock, the newlineboud worked great, thanks!

[sfaust]

ok, full of questions on this one. I have it working pretty much, so thanks for your help. However, I can't figure out how to tell the difference between a curved wall and a straight wall. All I see is the ability to get the two endpoints, so using the NewLineBound just creates a straight line between the ends.

This actually gets me most of the way to what I want, but it will say the walls are stacked above each other if the endpoints are the same, even if the radius is different...

Sorry, I've been searching through the API help menu and documentation, but there's a lot about curves that I just am not getting and am not finding much info on...

[david.bartliff]

Well here's some more pointers. I'm doing this very quickly without checking syntax, (and I dont use VB.NET)
The LocationCurve.Curve object will actually be a sub-class of Curve, e.g. Arc or Line. You can use the "is" operator to find out which - something like
if (cv.Curve is Autodesk.Revit.Geometry.Arc) ...

Once you know exactly what type of object it is, you can cast it if you need to, i.e. something like
Dimension MyArc as Autodesk.Revit.Geometry.Arc
MyArc = cv.Curve as Autodesk.Revit.Geometry.Arc (not at all sure about this statement)

Another thing to look at is Evaluate. If you have bound lines or arcs, (which you should have), then Evaluate(0.5) will either be halfway round an arc, or the middle of a line. I think you should be able to use 3 points to create a new arc, (equivalent to NewLineBound) if thats what you need to do.

[sfaust]

ok, good to know. I will check those out, thank you so much for your help!