celeritas::SimpleUnitTracker Class Reference

Track a particle in a universe of well-connected volumes. More...

#include <SimpleUnitTracker.hh>

Public Types
Type aliases
using	ParamsRef = NativeCRef< OrangeParamsData >
using	Initialization = detail::Initialization
using	Intersection = detail::Intersection
using	LocalState = detail::LocalState

Public Member Functions
CELER_FUNCTION	SimpleUnitTracker (ParamsRef const &params, SimpleUnitId id)
	Construct with reference to persistent parameter data.
CELER_FUNCTION LocalVolumeId::size_type	num_volumes () const
	Number of local volumes.
CELER_FUNCTION LocalSurfaceId::size_type	num_surfaces () const
	Number of local surfaces.
CELER_FUNCTION SimpleUnitRecord const &	unit_record () const
	SimpleUnitRecord for this tracker.
CELER_FUNCTION DaughterId	daughter (LocalVolumeId vol) const
	DaughterId of universe embedded in a given volume.
CELER_FUNCTION Initialization	initialize (LocalState const &state) const
	Find the local volume from a position.
CELER_FUNCTION Initialization	cross_boundary (LocalState const &state) const
	Find the local volume on the opposite side of a surface.
CELER_FUNCTION Intersection	intersect (LocalState const &state) const
	Calculate distance-to-intercept for the next surface.
CELER_FUNCTION Intersection	intersect (LocalState const &state, real_type max_dist) const
	Calculate distance-to-intercept for the next surface.
CELER_FUNCTION real_type	safety (Real3 const &pos, LocalVolumeId vol) const
	Calculate nearest distance to a surface in any direction.
CELER_FUNCTION Real3	normal (Real3 const &pos, LocalSurfaceId surf) const
	Calculate the local surface normal.
template<class F >
CELER_FUNCTION auto	intersect_impl (LocalState const &state, F &&is_valid) const -> Intersection
	Calculate distance-to-intercept for the next surface.
template<class F >
CELER_FUNCTION auto	background_intersect (LocalState const &state, F &&is_valid) const -> Intersection
	Calculate distance from the background volume to enter any other volume.

Detailed Description

Track a particle in a universe of well-connected volumes.

The simple unit tracker is based on a set of non-overlapping volumes comprised of surfaces. It is a faster but less "user-friendly" version of the masked unit tracker because it requires all volumes to be exactly defined by their connected surfaces. It does not check for overlaps.

Constructor & Destructor Documentation

SimpleUnitTracker()

CELER_FUNCTION celeritas::SimpleUnitTracker::SimpleUnitTracker ( ParamsRef const &  params, SimpleUnitId  suid  )

inline

Construct with reference to persistent parameter data.

Todo:

When adding multiple universes, this will calculate range of LocalVolumeIds that belong to this unit. For now we assume all volumes and surfaces belong to us.

Member Function Documentation

background_intersect()

template<class F >

CELER_FUNCTION auto celeritas::SimpleUnitTracker::background_intersect	(	LocalState const &	state,
		F &&	is_valid
	)		const -> Intersection

Calculate distance from the background volume to enter any other volume.

This function is accelerated with the BIH.

initialize()

CELER_FUNCTION auto celeritas::SimpleUnitTracker::initialize ( LocalState const &  state ) const

inline

Find the local volume from a position.

To avoid edge cases and inconsistent logical/physical states, it is prohibited to initialize from an arbitrary point directly onto a surface.

Todo:

This prohibition currently also extends to internal surfaces, even if both sides of that surface are "in" the current cell. We may need to relax that.

intersect_impl()

template<class F >

CELER_FUNCTION auto celeritas::SimpleUnitTracker::intersect_impl	(	LocalState const &	state,
		F &&	is_valid
	)		const -> Intersection

Calculate distance-to-intercept for the next surface.

The algorithm is:

• If the volume is the "background" then search externally for the next volume with background_intersect (equivalent of DistanceToIn for Geant4)
• Use the current volume to find potential intersecting surfaces and maximum number of intersections.
• Loop over all surfaces and calculate the distance to intercept based on the given physical and logical state. Save to the thread-local buffer only intersections that are valid (either finite or less than the user-supplied maximum). The buffer contains the distances, the face indices, and an index used for sorting (if the volume has internal surfaes).
• If no intersecting surfaces are found, return immediately. (Rely on the caller to set the "maximum distance" if we're not searching to infinity.)
• If the volume has no special cases, find the closest surface by calling simple_intersect.
• If the volume has internal surfaces call complex_intersect.

safety()

CELER_FUNCTION real_type celeritas::SimpleUnitTracker::safety ( Real3 const &  pos, LocalVolumeId  vol_id  ) const

inline

Calculate nearest distance to a surface in any direction.

The safety calculation uses a very limited method for calculating the safety distance: it's the nearest distance to any surface, for a certain subset of surfaces. Other surface types will return a safety distance of zero. Complex surfaces might return the distance to internal surfaces that do not represent the edge of a volume. Such distances are conservative but will necessarily slow down the simulation.

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

• SimpleUnitTracker.hh