Class RMGVertexConfinement

Nested Relationships

Nested Types

Inheritance Relationships

Base Type

Class Documentation

class RMGVertexConfinement : public RMGVVertexGenerator

Class for generating vertices in physical or geometrical volumes.

Public Types

enum class GeometricalSolidType

Different types of geometrical (user) defined solids.

Values:

enumerator kSphere
enumerator kCylinder
enumerator kBox
enum class SamplingMode

Strategy for sampling physical and geometrical volumes.

Can be either:

  • kIntersectPhysicalWithGeometrical : In which case vertices are generated in the intersection of the set of physical and geometrical volumes.

  • kUnionAll Generate in the union of all volumes, weighted by surface area / volume.

  • kSubtractGeometrical : Similar to kIntersectPhysicalWithGeometrical but specified regions can also be excluded.

Values:

enumerator kIntersectPhysicalWithGeometrical
enumerator kUnionAll
enumerator kSubtractGeometrical
enum class VolumeType

Types of volume to sample, either physical (a volume in the geometry), geometrical (defined by the user) or unset.

Values:

enumerator kPhysical
enumerator kGeometrical
enumerator kUnset

Public Functions

RMGVertexConfinement()
virtual void BeginOfRunAction(const G4Run *run) override
virtual void EndOfRunAction(const G4Run *run) override
virtual bool GenerateVertex(G4ThreeVector &v) override

Generate the actual vertex, according to the sampling mode (see RMGVertexConfinement::SamplingMode).

void AddPhysicalVolumeNameRegex(std::string name, std::string copy_nr = ".*")
inline void AddGeometricalVolume(GenericGeometricalSolidData &data)
void Reset()
inline void SetSamplingMode(SamplingMode mode)
inline void SetFirstSamplingVolumeType(VolumeType type)
inline std::vector<GenericGeometricalSolidData> &GetGeometricalSolidDataList()
struct GenericGeometricalSolidData

Information about the geometrical (user) defined solids.

Public Members

GeometricalSolidType solid_type = GeometricalSolidType::kBox
G4ThreeVector volume_center = G4ThreeVector(0, 0, 0)
double sphere_inner_radius = 0
double sphere_outer_radius = -1
double cylinder_inner_radius = 0
double cylinder_outer_radius = -1
double cylinder_height = -1
double cylinder_starting_angle = 0
double cylinder_spanning_angle = CLHEP::twopi
double box_x_length = -1
double box_y_length = -1
double box_z_length = -1
struct SampleableObject

An object which we can generate position samples in. Based on either a G4VPhysicalVolume or geometrical volume defined by a G4VSolid . The sampling can be performed either on the surface or in the volume of the solid.

This structure must contain at least a non-null pointer, between the physical_volume and sampling_solid arguments. The idea is that:

  • physical volumes get always a bounding box assigned, but at later time

  • purely geometrical volumes only have the sampling_solid member defined

Public Functions

SampleableObject() = default
SampleableObject(const SampleableObject&) = default
SampleableObject(G4VPhysicalVolume *physvol, G4RotationMatrix rot, G4ThreeVector trans, G4VSolid *solid, bool is_native_sampleable = false, bool on_surface = false)

SampleableObject constructor.

Parameters:

  • physvol – The physical volume.

  • rot – A rotation matrix for the sampling solid.

  • trans – A translation vector for the sampling solid.

  • solid – A solid for geometrical volume sampling or for generating candidate points or rejection sampling.

  • is_native_sampleable – A flag of whether the solid is natively sampeable.

  • on_surface – A flag of whether the solid should be sampled on the surface.

~SampleableObject() = default
bool IsInside(const G4ThreeVector &vertex) const

Check if the vertex is inside the solid.

Parameters:

vertex – The sampled vertex.

Returns:

Boolean flag of whether the vertexx is inside the solid.

bool Sample(G4ThreeVector &vertex, size_t max_attempts, bool force_containment_check, size_t &n_trials) const

Generate a sample from the solid.

Depending on if the solid is a basic one either sample natively, or using rejection sampling. Either samples the volume or the surface depending on the surface_sample member.

Parameters:

  • vertex – The sampled vertex.

  • max_attempts – The maximum number of candidate vertices for rejection sampling.

  • force_containment_check – Whether to force a check on where the point is inside the solid.

  • n_trials – The total number of trials performed.

bool GenerateSurfacePoint(G4ThreeVector &vertex, size_t max_attempts, size_t n_max) const

Generate a point on the surface of the solid.

This follows the algorithm from https://arxiv.org/abs/0802.2960.

  • Produce a direction vector corresponding to a uniform flux in a bounding sphere.

  • Find the intersections of this line with the solid.

  • Pick one intersection, or repeat.

Parameters:

  • vertex – The sampled vertex,

  • max_attempts – The maximum number of attempts to find a valid vertex.

  • n_max – The maximum number of intersections possible for the solid, can be an overestimate.

std::vector<G4ThreeVector> GetIntersections(G4ThreeVector start, G4ThreeVector dir) const

Get the number of intersections between the solid and the line starting at start with direction dir.

This is used in the generic surface sampling algorithm. This function makes use of the methods GetDistanceToIn(p,v) and GetDistanceToOut(p,v) of G4VSolid . It continually looks for the distance to the next boundary (along the line) until this becomes zero indicating there are no more intersections.

Parameters:

  • start – The starting vector of the line, note this should be outside the solid.

  • dir – The direction vector.

Returns:

A vector of the points of intersection.

void GetDirection(G4ThreeVector &dir, G4ThreeVector &pos) const

Get a position and direction for the generic surface sampling algorithm.

This generates a point on a bounding sphere, then shifts by some impact parameter, following the algorithm from https://arxiv.org/abs/0802.2960. This produces a uniform and isotropic flux inside the bounding sphere.

Parameters:

  • dir – The direction vector for the point.

  • pos – The initial position for the point.

Public Members

G4VPhysicalVolume *physical_volume = nullptr
G4VSolid *sampling_solid = nullptr
G4RotationMatrix rotation
G4ThreeVector translation
double volume = -1
double surface = -1
bool surface_sample = false
bool native_sample = false
int max_num_intersections = -1
struct SampleableObjectCollection

A collection of SampleableObjects . Can be used to sample from by selecting a volume weighted by surface area or volume.

Public Functions

SampleableObjectCollection() = default
inline ~SampleableObjectCollection()
const SampleableObject &SurfaceWeightedRand() const

Select a SampleableObject from the collection, weighted by surface area.

Returns:

a reference to the chosen SampleableObject .

const SampleableObject &VolumeWeightedRand() const

Select a SampleableObject from the collection, weighted by volume.

Returns:

a reference to the chosen SampleableObject .

bool IsInside(const G4ThreeVector &vertex) const
inline size_t size() const
inline SampleableObject &at(size_t i)
template<typename ...Args>
void emplace_back(Args&&... args)
inline bool empty() const
inline SampleableObject &back()
inline void clear()
inline void insert(SampleableObjectCollection &other)

Public Members

std::vector<SampleableObject> data = {}
double total_volume = 0
double total_surface = 0