celeritas::orangeinp::StackedExtrudedPolygon Class Reference

A convex/concave polygon extruded along a polyline, with scaling. More...

#include <StackedExtrudedPolygon.hh>

Inheritance diagram for celeritas::orangeinp::StackedExtrudedPolygon:

Public Types
Type aliases
using	SPConstObject = std::shared_ptr< ObjectInterface const >
using	VecReal = std::vector< real_type >
using	VecReal2 = std::vector< Real2 >
using	VecReal3 = std::vector< Real3 >
Public Types inherited from celeritas::orangeinp::ObjectInterface
using	SPConstObject = std::shared_ptr< ObjectInterface const >
using	VolumeBuilder = detail::VolumeBuilder

Public Member Functions
	StackedExtrudedPolygon (std::string &&label, VecReal2 &&polygon, VecReal3 &&polyline, VecReal &&scaling)
	Construct from a polygon, polyline, and scaling factors.
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.
VecReal3 const &	polyline () const
	Get the polyline.
VecReal const &	scaling () const
	Get the scaling factors.
Public Member Functions inherited from celeritas::orangeinp::ObjectInterface
virtual	~ObjectInterface ()=0
	Anchored default destructor.

Static Public Member Functions
static SPConstObject	or_solid (std::string &&label, VecReal2 &&polygon, VecReal3 &&polyline, VecReal &&scaling)
	Construct, or return an ExtrudedPolygon shape if possible.

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

Detailed Description

A convex/concave polygon extruded along a polyline, with scaling.

The polygon must be specified in clockwise order. The polyline must be strictly monotonically increasing in z. Scaling factors can be any positive value. Scaling is assumed to occur with respect to the polygon's original coordinate system.

Construction is performed using a convex decomposition approach (tor-convexdecomp-1984). The convex hull of the polygon is first found, then extruded along the polyline (with scaling) form a stack of ExtrudedPolygon shapes. Regions that constitute the difference between the polygon and its convex hull are then subtracted. Each of these regions is created recursively in the same fashion, i.e. finding the convex hull and creating a stack.

Because this method creates many regions, these are kept track of using three indices for debugging purposes: level, stack, and segment. The level index denotes the current recursion depth. The stack index denotes the convex region which is extruded into a stack on a given level. The segment index denotes the z segment within the stack. An example of these indices is shown below. Consider the following polygon, extruded along a single-segment polyline:

          __________
         |          |
      ___|          |
     |              |
     |              |
     |              |
     |            __|
     |           |
     |___________|

The convex hull of this polygon is used to create the first region:

          __________
        /           |
      /             |
     |   level 0    |
     |   stack 0    |
     |   segment 0  |
     |              |
     |             /
     |___________/

Recursing one level deeper, we create two additional regions:

          ...........
        /|  level 1, stack 0, segment 0
      /__|          .
     .              .
     .              .
     .              .
     .           ___.
     .          |  /  level 1, stack 1, segment 0
     ...........|/

and subtract their union from the first region.

When labeing nodes in the CSG output, the following shorthand format is used: label@level.stack.segment. For example, the final region in the example above might be named my_shape@1.1.0. 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 convex regions on this level, 2) .ncu : the negation of the union of all convex regions on this level, 3) .d : the difference between this level's convex hull and the convex regions on this level.

Member Function Documentation

build()

NodeId celeritas::orangeinp::StackedExtrudedPolygon::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::StackedExtrudedPolygon::label ( ) const

inlinefinalvirtual

Get the user-provided label.

Implements celeritas::orangeinp::ObjectInterface.

or_solid()

auto celeritas::orangeinp::StackedExtrudedPolygon::or_solid ( std::string &&  label, VecReal2 &&  polygon, VecReal3 &&  polyline, VecReal &&  scaling  )

static

Construct, or return an ExtrudedPolygon shape if possible.

Construct, or return an ExtrudedPolygon if possible.

output()

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

finalvirtual

Write the shape to JSON.

Implements celeritas::orangeinp::ObjectInterface.

---

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

• StackedExtrudedPolygon.hh
• StackedExtrudedPolygon.cc