Incrementally rotate a line using VB.net, C# or python

Hi Guys,

I am trying to incrementally rotate a line using the codes below in c# and Vb.net. The components show no error but they only overlap lines...Any idea what is going wrong? The python attempt just gave the strange message "i" unexpected token "i".

Many thanks,

on C#:

Arthur

private void RunScript(Curve ln, int x, double angle, ref object A)
{

List<Curve> lines = new List<Curve>();
Int16 i = default(Int16);

for(i = 0; i <= x; i++){
ln.Rotate(angle * i, Vector3d.ZAxis, ln.PointAtEnd);
lines.Insert(i, ln);
}

A = lines;

on VB.net:

Private Sub RunScript(ByVal ln As Curve, ByVal x As Integer, ByVal angle As Double, ByRef A As Object)

Dim lns As New List(Of Curve)()
Dim i As Int16

For i = 0 To x
ln.Transform(transform.Rotation(angle * i, vector3d.ZAxis, ln.PointAtEnd))
lns.Insert(i, ln)
Next

A = lns

in python I get the strange error : unexpected token "i"

For i in xrange(0,x):
rs.RotateObject(angle * i, vector3d.ZAxis, ln.PointAtEnd)
rs.AddLine(lns)
A = lns

Replies to This Discussion

Permalink Reply by Giulio Piacentino on April 4, 2012 at 2:10am

Hi Arthur,

could you upload what you have so far?

Thanks,

- Giulio
_______________
giulio@mcneel.com

Permalink Reply by Arthur Mamou-Mani on April 4, 2012 at 4:52am

Hi Giulio,

Thanks for your reply!

Please see attached files.

arthur

Attachments:

lines_scripting_.gh, 4 KB

Permalink Reply by Giulio Piacentino on April 4, 2012 at 6:04am

Hi Arthur,

there were some minor syntax mistakes but one big issue: you should remember to copy objects if you do not want your changes to be not propagated from one tranformation to the next one.

(I've added a rhinoscriptsyntax and a RhinoCommon version of the Python script. Rhinoscriptsyntax works in degrees).

Thanks,

- Giulio
________________
giulio@mcneel.com

Attachments:

lines_scripting_2.gh, 5 KB

Permalink Reply by Arthur Mamou-Mani on April 4, 2012 at 7:01pm

Wow thank you so much Giulio! This is so helpful.

I am adding this screenshot which might also help people to understand some of the difference between languages:

Permalink Reply by Ángel Linares on April 5, 2012 at 7:33am

Thanks for sharing! I'm studying C# and Python these days and is a really usefull thing.

Permalink Reply by Steven on September 8, 2014 at 3:10am

I've been trying a similar thing, but transforming points in a list and it doesn't seem to work:

profile_points(2).Transform(transform.Rotation(angle, vector3d.ZAxis, New point3d(0, 0, 0)))

This doesn't seem to actually rotate the point, although it doesn't throw an error.

Permalink Reply by Steven on September 8, 2014 at 3:14am

I should add that the list of points was created within the script, not brought in through the input parameters.

Permalink Reply by David Rutten on September 8, 2014 at 3:38am

Point3D is a structure, not a class. When you get a point from a list, you get a copy of that point. Then you transform the copy and ultimately you forget about the copy. You'll need to put the new point back into the list:

Dim point As Point3d = profile_points(2)

point.Transform(Transform.Rotation(...))

profile_points(2) = point

David Rutten

david@mcneel.com

Permalink Reply by Steven on September 11, 2014 at 9:20pm

Thanks David! I've just been reading about the differences between classes and structures and would like to clarify if the following is correct: As point3d is a structure, when you say "point = profile_point" an exact, independant copy is created. However, with classes such as the 'Curve' class, a reference to profile_curve will be copied if you say "curve = profile_curve". Does that mean if you modify 'curve', you will also modify 'profile_curve'?

Permalink Reply by David Rutten on September 12, 2014 at 3:16am

That is correct. If you want to get a curve from somewhere, modify the curve whilst making sure you don't modify the original, you have to duplicate the curve first.

Permalink Reply by Hechang on April 9, 2012 at 9:19am

came across same problem. thanks for sharing~~~~~

Permalink Reply by Matthew on October 24, 2013 at 10:04am

I'm quite new to Python (and programming in general), but could your problem not be solved by assigning the variable i a value before trying to call it?

i = 0

for i in range(0,x):

rs.RotateObject(....

please forgive me if that is waaaaaayy low level... :D