 Home Page > KernelCAD Components > Interfaces > Open Cascade Technology > GP > IKO_gp_Ax3
IKO_gp_Ax3
IKO_gp_Ax3 Interface
Describes a coordinate system in 3D space. Unlike a gp_Ax2 coordinate system, a
gp_Ax3 can be right-handed ("direct sense") or left-handed ("indirect sense"). A
coordinate system is defined by: its origin (also referred to as its "Location
point"), and three orthogonal unit vectors, termed 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
Direction" or the "Y Direction", "Direction" is not modified. "Direction" is
also the "Z Direction". The "main Direction" is always parallel to the cross
product of its "X Direction" and "Y Direction". If the coordinate system is
right-handed, it satisfies the equation: "main Direction" = "X Direction" ^ "Y
Direction" and if it is left-handed, it satisfies the equation: "main Direction"
= -"X Direction" ^ "Y Direction" 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 three axes", or to define geometric transformations. Note: We refer to
the "X Axis", "Y Axis" and "Z Axis", respectively, as the axes having: the
origin of the coordinate system as their origin, and the unit vectors "X
Direction", "Y Direction" and "main Direction", respectively, as their unit
vectors. The "Z Axis" is also the "main Axis". gp_Ax2 is used to define a
coordinate system that must be always right-handed.
- ReverseAxis
- Direct
HRESULT ReverseAxis(int axis)
Parameters
axis -[in] 0-based index of an axis
- Remarks:
Reverses direction of the axis
HRESULT Direct(VARIANT_BOOL* res)
res - [out,retval] - Returned orientation of this
Returns True if the coordinate system is right-handed. i.e.
XDirection().Crossed(YDirection()).Dot(Direction()) > 0
|