| | Describes functions to construct pipes. A pipe is built by
sweeping a curve (the section) along another curve (the path).
The Pipe class provides the following types of construction:
- pipes with a circular section of constant radius,
- pipes with a constant section,
- pipes with a section evolving between two given curves.
All standard specific cases are detected in order to build,
where required, a plane, cylinder, cone, sphere, torus,
surface of linear extrusion or surface of revolution.
Generally speaking, the result is a BSpline surface (NURBS).
A Pipe object provides a framework for:
- defining the pipe to be built,
- implementing the construction algorithm, and
- consulting the resulting surface.
There are several methods to instantiate a Pipe:
1) give a path and a radius : the section is
a circle. This location is the first point
of the path, and this direction is the first
derivate (calculate at the first point ) of
the path.
2) give a path and a section.
Differtent options are available
2.a) Use the classical Frenet trihedron
- or the CorrectedFrenet trihedron
(To avoid twisted surface)
- or a constant trihedron to have all the sections
in a same plane
2.b) Define a ConstantBinormal Direction to keep the
same angle beetween the Direction and the sections
along the sweep surface.
2.c) Define the path by a surface and a 2dcurve,
the surface is used to define the trihedron's normal.
It is usefull to keep a constant angle beetween
input surface and the pipe. --
3) give a path and two sections. The section
evoluate from First to Last Section.
3) give a path and N sections. The section
evoluate from First to Last Section.
In general case the result is a NURBS. But we
can generate plane, cylindrical, spherical,
conical, toroidal surface in some particular case.
The natural parametrization of the result is:
U-Direction along the section.
V-Direction along the path.
But, in some particular case, the surface must
be construct otherwise.
The method "EchangeUV" return false in such cases.
More...
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1.6.3