TopTrans — OpenCascade.js

TopTrans_CurveTransition

This algorithm is used to compute the transition of a Curve intersecting a curvilinear boundary.
The geometric elements are described locally at the intersection point by a second order development.
The curve is described by the intersection point, the tangent vector and the curvature.
The boundary is described by a set of curve elements, a curve element is either :

A curve.
A curve and an orientation called a half-curve, the boundary of the curve is before or after the intersection point depending on the orientation.

Constructors(1)

constructor(): TopTrans_CurveTransition
Create an empty Curve Transition.

Instance methods(5)

Reset(Tgt: gp_Dir, Norm: gp_Dir, Curv: number): void
Initialize a Transition with the local description of a Curve.
Parameters (3)
- Tgt
- Norm
- Curv
Reset(Tgt: gp_Dir): void
Initialize a Transition with the local description of a straight line.
Parameters (1)
- Tgt
Compare(Tole: number, Tang: gp_Dir, Norm: gp_Dir, Curv: number, S: TopAbs_Orientation, Or: TopAbs_Orientation): void
Add a curve element to the boundary. If Or is REVERSED the curve is before the intersection, else if Or is FORWARD the curv is after the intersection and if Or is INTERNAL the intersection is in the middle of the curv.
Parameters (6)
- Tole
- Tang
- Norm
- Curv
- S
- Or
StateBefore(): TopAbs_State
returns the state of the curve before the intersection, this is the position relative to the boundary of a point very close to the intersection on the negative side of the tangent.
StateAfter(): TopAbs_State
returns the state of the curve after the intersection, this is the position relative to the boundary of a point very close to the intersection on the positive side of the tangent.

TopTrans_SurfaceTransition

This algorithm is used to compute the transition of a 3D surface intersecting a topological surfacic boundary on a 3D curve ( intersection curve ). The boundary is described by a set of faces each face is described by.

its support surface,
an orientation defining its matter side. The geometric elements are described locally at the intersection point by a second order development. A surface is described by the normal vector, the principal directions and the principal curvatures. A curve is described by the tangent, the normal and the curvature.
The algorithm keeps track of the two faces elements closest to the part of the curve "before" and "after" the intersection, these two elements are updated for each new face.
The position of the curve can be computed when at least one surface element has been given, this position is "In","Out" or "On" for the part of the curve "Before" or "After" the intersection.

Constructors(1)

constructor(): TopTrans_SurfaceTransition
Create an empty Surface Transition.

Static methods(2)

GetBefore(Tran: TopAbs_Orientation): TopAbs_State
Parameters (1)
- Tran
GetAfter(Tran: TopAbs_Orientation): TopAbs_State
Parameters (1)
- Tran

Instance methods(6)

Reset(Tgt: gp_Dir, Norm: gp_Dir, MaxD: gp_Dir, MinD: gp_Dir, MaxCurv: number, MinCurv: number): void
Initialize a Surface Transition with the local description of the intersection curve and of the reference surface. PREQUESITORY : Norm oriented OUTSIDE "geometric matter".
Parameters (6)
- Tgt
- Norm
- MaxD
- MinD
- MaxCurv
- MinCurv
Reset(Tgt: gp_Dir, Norm: gp_Dir): void
Initialize a Surface Transition with the local description of a straight line.
Parameters (2)
- Tgt
- Norm
Compare(Tole: number, Norm: gp_Dir, MaxD: gp_Dir, MinD: gp_Dir, MaxCurv: number, MinCurv: number, S: TopAbs_Orientation, O: TopAbs_Orientation): void
Add a face element to the boundary.
- S defines topological orientation for the face : S FORWARD means: along the intersection curve on the reference surface, transition states while crossing the face are OUT,IN. S REVERSED means states are IN,OUT. S INTERNAL means states are IN,IN.
- O defines curve's position on face : O FORWARD means the face is before the intersection O REVERSED means the face is AFTER O INTERNAL means the curve intersection is in the face. PREQUESITORY : Norm oriented OUTSIDE "geometric matter"
Parameters (8)
- Tole
- Norm
- MaxD
- MinD
- MaxCurv
- MinCurv
- S
- O
Compare(Tole: number, Norm: gp_Dir, S: TopAbs_Orientation, O: TopAbs_Orientation): void
Add a plane or a cylindric face to the boundary.
Parameters (4)
- Tole
- Norm
- S
- O
StateBefore(): TopAbs_State
Returns the state of the reference surface before the interference, this is the position relative to the surface of a point very close to the intersection on the negative side of the tangent.
StateAfter(): TopAbs_State
Returns the state of the reference surface after interference, this is the position relative to the surface of a point very close to the intersection on the positive side of the tangent.