VB.NET set wcs help

[smitty239]

Hi Everyone
I am trying to write a program that with user input sets the wcs. UG documentation says to use this

Public Sub SetOriginAndMatrix(ByVal origin As NXOpen.Point3d, ByVal matrix As NXOpen.Matrix3x3)

getting the 3 points is easy my problem is how do you figure out what the 3 x 3 matrix is? I know what the numbers mean but I have no idea how to figure them out it is different for every wcs position and there is no documentation for how to figure it out. Please help !!!!!

Smitty

 

[cowski]

The 3x3 matrix is probably a rotation matrix (relative to the absolute csys) that will give the orientation of the new csys. Here is a link that will explain more:

http://www.euclideanspace.com/maths/algebra/matrix/orthogonal/rotation/index.htm

Or if you type 'rotation matrix' into your favorite search engine it will turn up lots of other links.

I don't currently have a .NET enabled version of NX to verify this on, but it is my best guess.

 

[MSPBenson]

Smitty,

The "point3d" is the origin of the new wcs from absolute (X0,Y0,Z0)
The 3x3 matrix is basiclly the coordinates from absolute of a point on the new wcs x axis, a point on the new wcs y axis, and a point on the new wcs z axis.
As each point has an x,y,z coordainte you get 3 values for each of the 3 points defining the axis giving you a 3x3 matrix.

X1 Y1 Z1

Xx Yx Zx
Xy Yy Zy
Xz Yz Zz

If you record a journal with a very basic wcs move it will create the 3x3 matrix and you can get a feel for how to define each of these movements in the array.





Mark Benson
Aerodynamic Model Designer

 

[smitty239]

I have ran the journal and for a very simple move of the wcs it is very straight forward. it gets very difficult to compute the numbers when the wcs gets moved where all 3 axis are moved. the matrix is calculated from absolute i know that it's the calculations that are giving me a hard time as how to actually calculate them.

thanks