How to create a coordinate system based on direction vectors and a specific origin?

Rohith Patchigolla

I have principal axis vectors and center of gravity of a body. Now I want to create a coordinate system based on these vectors and center. But, Mechanical doesn't let me input vector information.

Rohith Patchigolla

This script is tested in 2022R2. Simply open Mechanical --> go to Automation Tab --> hit Scripting button and paste the below script in Script Editor -> Run script

#Inputs
#Center of Gravity
Xcog = Quantity(100,'mm')
Ycog = Quantity(200,'mm')
Zcog = Quantity(300,'mm')

#Principal Axis Vectors
Xaxis = [0.99997, -0.00777, -0.00092]
Yaxis = [0.00772, 0.99886, -0.04717]
#Zaxis = [0.00129, 0.04716, 0.99889]

def create_beams_from_points(reinforcements_point_list):
 with Transaction(True):
    ExtAPI.DataModel.Project.Model.AddConstructionGeometry()
    construction_line=ExtAPI.DataModel.Project.Model.ConstructionGeometry.AddConstructionLine()
    for pointlist in reinforcements_point_list:
        points=construction_line.CreatePoints(pointlist)
        for i in range(0,len(points)-1):
          edge = construction_line.CreateStraightLines([points[i],points[i+1]], [(0,1)])
    part_geo = construction_line.AddToGeometry()
    part = ExtAPI.DataModel.Project.Model.Geometry.GetPart(part_geo)
    geo_bodies= part_geo.Bodies
    treebodies=map(lambda x: ExtAPI.DataModel.Project.Model.Geometry.GetBody(x), geo_bodies)

points1 =[[(Xcog.Value,Ycog.Value,Zcog.Value), (Xcog.Value+Xaxis[0], Ycog.Value+Xaxis[1],Zcog.Value+Xaxis[2])]]
create_beams_from_points(points1)

points2 =[[(Xcog.Value,Ycog.Value,Zcog.Value), (Xcog.Value+Yaxis[0], Ycog.Value+Yaxis[1],Zcog.Value+Yaxis[2])]]
create_beams_from_points(points2)

constructionLines = list(DataModel.GetObjectsByType(DataModelObjectCategory.ConstructionLine))
lineX = constructionLines[-2]
lineY = constructionLines[-1]

beamX_Id = lineX.GetPartFromGeometry().Bodies[0].Edges[0].Id
beamY_Id = lineY.GetPartFromGeometry().Bodies[0].Edges[0].Id

with Transaction(True):
    #Add Coordinate System
    myCsys = Model.CoordinateSystems.AddCoordinateSystem()
    myCsys.OriginDefineBy = CoordinateSystemAlignmentType.Fixed
    myCsys.OriginX = Xcog
    myCsys.OriginY = Ycog
    myCsys.OriginZ = Zcog

    myCsys.PrimaryAxis = CoordinateSystemAxisType.PositiveXAxis
    myCsys.SecondaryAxis = CoordinateSystemAxisType.PositiveYAxis
    myCsys.PrimaryAxisDefineBy = CoordinateSystemAlignmentType.Associative
    myCsys.SecondaryAxisDefineBy = CoordinateSystemAlignmentType.Associative

    beamX_Sel = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)
    beamX_Sel.Ids = [beamX_Id]

    beamY_Sel = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)
    beamY_Sel.Ids = [beamY_Id]

    myCsys.PrimaryAxisLocation = beamX_Sel
    myCsys.SecondaryAxisLocation = beamY_Sel

    myCsys.PrimaryAxisDefineBy = CoordinateSystemAlignmentType.Fixed
    myCsys.SecondaryAxisDefineBy = CoordinateSystemAlignmentType.Fixed

    lineX.RemoveFromGeometry()
    lineY.RemoveFromGeometry()

    DataModel.Remove(lineX)
    DataModel.Remove(lineY)

Created Coordiante System

Landon Mitchell Kanner

You might also be interested in some of the functions in the attached file, such as RotCS(cs,Axes).