EBGeometry::CapsuleSDF< T > Class Template Reference

Signed distance field for a capsule (pill shape): a cylinder capped with hemispheres. More...

#include <EBGeometry_AnalyticDistanceFunctions.hpp>

Inheritance diagram for EBGeometry::CapsuleSDF< T >:

Collaboration diagram for EBGeometry::CapsuleSDF< T >:

Public Member Functions
	CapsuleSDF ()=default
	Default constructor. Constructs a capsule with tips at (0,-1,0) and (0,1,0), radius 0.5.
	CapsuleSDF (const Vec3T< T > &a_tip1, const Vec3T< T > &a_tip2, const T &a_radius) noexcept
	Full constructor.
	CapsuleSDF (const CapsuleSDF &)=default
	Copy constructor.
	CapsuleSDF (CapsuleSDF &&)=default
	Move constructor.
CapsuleSDF &	operator= (const CapsuleSDF &)=default
	Copy assignment.
CapsuleSDF &	operator= (CapsuleSDF &&)=default
	Move assignment.
	~CapsuleSDF () override=default
	Destructor.
T	signedDistance (const Vec3T< T > &a_point) const noexcept override
	Signed distance function for the capsule.
Public Member Functions inherited from EBGeometry::SignedDistanceFunction< T >
	SignedDistanceFunction ()=default
	Default constructor.
	~SignedDistanceFunction () override=default
	Destructor.
T	value (const Vec3T< T > &a_point) const noexcept final
	Implementation of ImplicitFunction::value; delegates to signedDistance().
virtual Vec3T< T >	normal (const Vec3T< T > &a_point, const T &a_delta) const noexcept
	Compute the outward normal using central finite differences.
Public Member Functions inherited from EBGeometry::ImplicitFunction< T >
	ImplicitFunction ()=default
	Default constructor.
virtual	~ImplicitFunction ()=default
	Default destructor.
T	operator() (const Vec3T< T > &a_point) const noexcept
	Call operator — alternative signature for the value function.
template<class BV >
BV	approximateBoundingVolumeOctree (const Vec3T< T > &a_initialLowCorner, const Vec3T< T > &a_initialHighCorner, const unsigned int a_maxTreeDepth, const T &a_safety=0.0) const
	Compute an approximation to the bounding volume for the implicit surface using octree subdivision.

Protected Attributes
Vec3T< T >	m_center1 = Vec3T<T>(T(0), T(-0.5), T(0))
	Center of one hemispherical cap.
Vec3T< T >	m_center2 = Vec3T<T>(T(0), T(0.5), T(0))
	Center of the other hemispherical cap.
T	m_radius = T(0.5)
	Capsule radius.

Detailed Description

template<class T>
class EBGeometry::CapsuleSDF< T >

Signed distance field for a capsule (pill shape): a cylinder capped with hemispheres.

A capsule is defined by two outer tip positions and a radius. The tips are the outermost points of each hemispherical endcap. The total length (tip to tip) equals distance(tip1, tip2). The internal cylindrical body has length distance(tip1, tip2) - 2 * radius, and the two hemispheres each contribute a further radius to each end.

Internally the hemisphere centres are stored as m_center1 and m_center2 (inset from the tips by radius along the capsule axis). These are not the same as the tip positions passed to the constructor.

The SDF is negative inside the capsule and positive outside. By default the capsule is centred at the origin, aligned along y, with tips at (0,-1,0) and (0,1,0) and radius 0.5, giving a total height of 2 and a cylindrical body of length 1.

Template Parameters

T	Floating-point precision.

Constructor & Destructor Documentation

CapsuleSDF() [1/2]

template<class T >

EBGeometry::CapsuleSDF< T >::CapsuleSDF ( )

default

Default constructor. Constructs a capsule with tips at (0,-1,0) and (0,1,0), radius 0.5.

Total height = 2, cylindrical body length = 1, aligned along y, centred at origin. The stored hemisphere centres are at (0,-0.5,0) and (0,0.5,0).

CapsuleSDF() [2/2]

template<class T >

EBGeometry::CapsuleSDF< T >::CapsuleSDF ( const Vec3T< T > &  a_tip1, const Vec3T< T > &  a_tip2, const T &  a_radius  )

inlinenoexcept

Full constructor.

The hemisphere centres stored internally are derived from the tips: m_center1 = a_tip1 + a_radius * axis and m_center2 = a_tip2 - a_radius * axis, where axis = (a_tip2 - a_tip1) / distance(a_tip1, a_tip2). The cylindrical body length is distance(a_tip1, a_tip2) - 2 * a_radius; for a valid non-degenerate shape this must be positive, i.e. distance(a_tip1, a_tip2) > 2 * a_radius.

Parameters

[in]	a_tip1	Outer tip of one hemispherical cap (outermost point in that direction).
[in]	a_tip2	Outer tip of the other hemispherical cap.
[in]	a_radius	Capsule radius (applied to both the tube and the hemispherical caps).

Member Function Documentation

operator=() [1/2]

template<class T >

CapsuleSDF & EBGeometry::CapsuleSDF< T >::operator= ( CapsuleSDF< T > &&  )

default

Move assignment.

Returns

Reference to (*this).

operator=() [2/2]

template<class T >

CapsuleSDF & EBGeometry::CapsuleSDF< T >::operator= ( const CapsuleSDF< T > &  )

default

Copy assignment.

Returns

Reference to (*this).

signedDistance()

template<class T >

T EBGeometry::CapsuleSDF< T >::signedDistance ( const Vec3T< T > &  a_point ) const

inlineoverridevirtualnoexcept

Signed distance function for the capsule.

Parameters

[in]

a_point

Position.

Returns

Signed distance from a_point to the capsule surface; negative inside.

Implements EBGeometry::SignedDistanceFunction< T >.

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

• Source/EBGeometry_AnalyticDistanceFunctions.hpp