DG Kernel Documentation


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IKO_gp_Ax2 Interface

Describes a right-handed coordinate system in 3D space.
A coordinate system is defined by:

  • its origin (also referred to as its "Location point"), and
  • three orthogonal unit vectors, termed respectively the
    "X Direction", the "Y Direction" and the "Direction" (also
    referred to as the "main Direction").
    The "Direction" of the coordinate system is called its
    "main Direction" because whenever this unit vector is
    modified, the "X Direction" and the "Y Direction" are
    recomputed. However, when we modify either the "X <br> Direction" or the "Y Direction", "Direction" is not modified.
    The "main Direction" is also the "Z Direction".
    Since an Ax2 coordinate system is right-handed, its
    "main Direction" is always equal to the cross product of
    its "X Direction" and "Y Direction". (To define a
    left-handed coordinate system, use gp_Ax3
    A coordinate system is used:
  • to describe geometric entities, in particular to position
    them. The local coordinate system of a geometric
    entity serves the same purpose as the STEP function
    "axis placement two axes", or
  • to define geometric transformations.
    Note: we refer to the "X Axis", "Y Axis" and "Z Axis",
    respectively, as to axes having:
  • the origin of the coordinate system as their origin, and
  • the unit vectors "X Direction", "Y Direction" and "main <br> Direction", respectively, as their unit vectors.
    The "Z Axis" is also the "main Axis".

Query IKO_gp_Object from this interface to obtain or modify location and orientation of the plane

Query IKO_gp_Transformation to transform position and orientation

Query IKO_Standard_Object to create a copy or obtain type name

Methods:

SetDirection
Direction
SetLocation
Location
SetXDirection
XDirection
SetYDirection
YDirection
Axis

HRESULT SetDirection(DIVect* V)

Parameters

V -[in] Direction vector


HRESULT SetDirection(DIVect* vZAxis)

Sets direction of Z axis


HRESULT Direction(DIVect* vZAxis)

Returns direction of Z axis


HRESULT SetLocation(DIPoint* pt)

pt -[in] Location of the system


HRESULT Location(DIPoint* pt)

Retuns location of system


HRESULT SetXDirection(DIVect* V)

Changes the "Xdirection" of . The main direction "Direction" is not modified, the "Ydirection" is modified. If is not normal to the main direction then is computed as follows XDirection = Direction ^ (Vx ^ Direction). Exceptions Standard_ConstructionError if Vx or Vy is parallel to the "main Direction" of this coordinate system.


HRESULT XDirection(DIVect* V)

Returns X direction


HRESULT SetYDirection(DIVect* V)

Changes the "Ydirection" of this. The main direction is not modified but the "Xdirection" is changed. If is not normal to the main direction then "YDirection" is computed as follows YDirection = Direction ^ ( ^ Direction). Exceptions Standard_ConstructionError if Vx or Vy is parallel to the "main Direction" of this coordinate system.


HRESULT YDirection(DIVect* V)of and Ax1* OReturns Y direction


HRESULT Axis(IKO_gp_Ax1** ZAxis)

Returns the main axis of . It is the "Location" point and the main "Direction".