Rotation Script

Hey all, so i'm totally new to scripting and i'm wondering how can this be done

Evaluate the angle (a) between a vector and x axis

If (a) is positive

then rotate the vector about z axis with angle value (-a)

else rotate the vector about z axis with angle value (a)

I thought of dispatching the vector list with a logic button on gh and having two rotation "processes", but the problem is that i need the original order of the list for later operations

Thank in advance!

Replies to This Discussion

Permalink Reply by Fred Becquelin on May 12, 2014 at 3:36am

Angle in 3d are always positive and in [0, PI].

You need to supply a plane to get an oriented angle (think of the argument of a complex number...)

Permalink Reply by djordje on May 12, 2014 at 3:42am

You're right. I can not. I apologize for that.
For some reason the plane's z axis gets flipped once you pass the pi angle:

Attachments:

vector_angle.gh, 16 KB

Permalink Reply by Danny Boyes on May 12, 2014 at 4:19am

It boils down to this. Whenever you measure the angle between 2 vectors and generate the plane from the same two vectors you will get a 0 to PI. If you then measure a third vector but use the Plane based on the first two you can have anything from 0 to 2*PI.