celeritas::orangeinp::RevolvedPolygon Class Reference

An azimuthally sliced arbitrary polygon revolved around the z axis. More...

#include <RevolvedPolygon.hh>

Inheritance diagram for celeritas::orangeinp::RevolvedPolygon:

Public Types
Type aliases
using	SPConstObject = std::shared_ptr< ObjectInterface const >
using	VecReal2 = std::vector< Real2 >
Public Types inherited from celeritas::orangeinp::ObjectInterface
using	SPConstObject = std::shared_ptr< ObjectInterface const >
using	VolumeBuilder = detail::VolumeBuilder

Public Member Functions
	RevolvedPolygon (std::string &&label, VecReal2 &&polygon, EnclosedAzi &&enclosed)
	Construct from a polygon.
std::string_view	label () const final
	Get the user-provided label.
NodeId	build (VolumeBuilder &) const final
	Construct a volume from this object.
void	output (JsonPimpl *) const final
	Write the shape to JSON.
VecReal2 const &	polygon () const
	Get the polygon.
EnclosedAzi const &	enclosed_azi () const
	Get the azimuthal angular restriction.
Public Member Functions inherited from celeritas::orangeinp::ObjectInterface
virtual	~ObjectInterface ()=0
	Anchored default destructor.

Additional Inherited Members
Protected Member Functions inherited from celeritas::orangeinp::ObjectInterface
	CELER_DEFAULT_COPY_MOVE (ObjectInterface)

Detailed Description

An azimuthally sliced arbitrary polygon revolved around the z axis.

The polygon must be specified in counterclockwise order and may not be self intersecting. The polygon cannot cross the z axis, i.e., all vertices must satisfy r >= 0.

Construction is performed using a convex differences tree approach (tor-convexdecomp-1984). The convex hull of the polygon is first found and revolved around the z axis. Regions that constitute the difference between the convex hull and the original polygon are then subtracted. Each of these regions is created recursively in the same fashion. The recursion depth is referred to as the "level" and each contiguous region within a level is a "region", as shown below:

original polygon         convex hull          difference
  |___     ____         |____________       |   ______
^ |   \    |  |         |           |       |   \    |  level 1
| |     \  |  |         |           |       |     \  |  region 0
z |       \|  |         | level 0   |       |       \|
  |           |    =    | region 0  |   -   |
a |           |         |           |       |
x |    /\     |         |           |       |     /\     level 1
i |___/  \____|         |___________|       |    /__\    region 1
s |_____________        |_____________      |_____________
   r axis ->

Convex "regions" are constructed from "subregions", as shown below:

  |   ______             |________                     |___
^ |   \    |  level 1    |        | level 1            |   \     level 1
| |     \  |  region 0   |        | region 0           |     \   region 0
z |       \|             |________| subregion 0        |_______\ subregion 1
  |                 =    |          (a cylinder)  -    |         (a cone)
a |                      |                             |
x |                      |                             |
i |                      |                             |
s |_____________         |_____________                |_____________
     r axis ->

In this example, level 1 region 0 is formed from only two subregions, but the general case is handled via:

region = union(outer subregions) - union(inner subregions).

The final step in construction is azimuthal truncation, which is done through a union operation with a negated or non-negated EnclosedAzi.

When labeling nodes in the CSG output, the following shorthand format is used: label@level.region.subregion. For example, the final subregion in the example above might be named my_shape@1.0.1. For each level, additional nodes are created in the form: label@level.suffix where suffixes have the following meanings:

1) .cu : the union of all concave regions on the level, 2) .ncu : the negation of .cu, 3) .d : the difference between the level's convex hull and .cu.

For each region, additional nodes are created in the form label.nosp@m.@lev.nosp@m.el.re.nosp@m.gion.nosp@m..suff.nosp@m.ix where suffixes have the following meanings:

1) .ou : the union of nodes that comprise the outer boundary of the region, 2) .iu : the union of nodes that comprise the inner boundary of the region, 3) .nui : the negation of .ui, 4) .d : the difference between .ou and .iu.

If the supplied EnclosedAzi object is not [0, 2pi], additional nodes with the following extensions are added:

1) azi/~azi : the enclosed, possibly negated, azimuthal angle, 2) restricted : the intersection of the revolved polygon and azi/~azi.

Member Function Documentation

build()

NodeId celeritas::orangeinp::RevolvedPolygon::build ( VolumeBuilder &  vb ) const

finalvirtual

Construct a volume from this object.

Construct a volume from this shape.

Implements celeritas::orangeinp::ObjectInterface.

label()

std::string_view celeritas::orangeinp::RevolvedPolygon::label ( ) const

inlinefinalvirtual

Get the user-provided label.

Implements celeritas::orangeinp::ObjectInterface.

output()

void celeritas::orangeinp::RevolvedPolygon::output ( JsonPimpl *  j ) const

finalvirtual

Write the shape to JSON.

Implements celeritas::orangeinp::ObjectInterface.

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The documentation for this class was generated from the following files:

• RevolvedPolygon.hh
• RevolvedPolygon.cc