Struct Capsule3D

A 3D capsule represented by two end-points PointA and PointB and a Radius. The capsule volume is the set of all points within Radius of the line segment connecting the two end-points, equivalent to a cylinder capped with two hemispherical ends.

Implements

IEquatable<Capsule3D>

Inherited Members

object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

Namespace: Scylla.Core.Util.Geom

Assembly: ScyllaCore.dll

Syntax

[Serializable]
public struct Capsule3D : IEquatable<Capsule3D>

Remarks

This two-endpoint form matches the parameters of CapsuleCast(Vector3, Vector3, float, Vector3, float, int, QueryTriggerInteraction) exactly, supports arbitrary orientation without a separate quaternion field, and degenerates cleanly to a sphere when PointA equals PointB.

Radius is expected to be non-negative. Behaviour with a negative radius is undefined.

Equality comparisons use Approximately(float, float, float) for each component of PointA, PointB, and Radius, so two capsules that differ only by floating-point rounding are considered equal.

To obtain a conservative axis-aligned bounding box, call ToAABB3D(). For a standalone sphere without a central segment, see Sphere3D.

Constructors

Capsule3D(Vector3, Vector3, float)

Initializes a new Capsule3D with the supplied end-points and radius.

Declaration

public Capsule3D(Vector3 pointA, Vector3 pointB, float radius)

Parameters

Type	Name	Description
Vector3	pointA	One end-point of the capsule's central segment.
Vector3	pointB	The other end-point of the capsule's central segment.
float	radius	The radius of the capsule in world units. Should be non-negative.

Fields

PointA

One end-point of the capsule's central line segment. Together with PointB, this defines the axis of the capsule's cylindrical body.

Declaration

[SerializeField]
public Vector3 PointA

Field Value

Type	Description
Vector3

PointB

The other end-point of the capsule's central line segment. Together with PointA, this defines the axis of the capsule's cylindrical body.

Declaration

[SerializeField]
public Vector3 PointB

Field Value

Type	Description
Vector3

Radius

Radius of the capsule in world units. This is the radius of both the cylindrical body and the two hemispherical end-caps. Expected to be non-negative.

Declaration

[SerializeField]
public float Radius

Field Value

Type	Description
float

Properties

Axis

The normalized direction vector of the central segment, pointing from PointA toward PointB. Returns UnityEngine.Vector3.up when the two end-points are identical (degenerate capsule).

Declaration

public readonly Vector3 Axis { get; }

Property Value

Type	Description
Vector3

Center

The midpoint of the capsule's central segment, equidistant from both end-points.

Declaration

public readonly Vector3 Center { get; }

Property Value

Type	Description
Vector3

Height

The total height of the capsule, including both hemispherical end-caps. Equals the length of the central segment (|PointB - PointA|) plus Radius * 2. When PointA equals PointB (degenerate sphere) this is simply the diameter.

Declaration

public readonly float Height { get; }

Property Value

Type	Description
float

Volume

The total volume enclosed by the capsule, in cubic world units. This is the sum of the cylindrical body volume (pi * r^2 * segmentLength) and the combined hemispherical caps, which together form a full sphere of volume (4/3) * pi * r^3.

Declaration

public readonly float Volume { get; }

Property Value

Type	Description
float

Methods

ClosestPoint(Vector3)

Returns the closest point on or inside the capsule to point. If point is already inside the capsule, it is returned unchanged.

Declaration

public readonly Vector3 ClosestPoint(Vector3 point)

Parameters

Type	Name	Description
Vector3	point	The query point in world space.

Returns

Type	Description
Vector3	The nearest point within the capsule volume to `point`. For points outside the capsule, this is the point on the capsule's surface that is nearest to `point`, obtained by projecting `point` onto the central segment and then moving toward `point` by Radius.

Contains(Vector3)

Returns true if point is inside or on the surface of this capsule, i.e. if the distance from point to the central segment is less than or equal to Radius.

Declaration

public readonly bool Contains(Vector3 point)

Parameters

Type	Name	Description
Vector3	point	The world-space point to test.

Returns

Type	Description
bool	`true` if `point` lies within the closed volume of the capsule; `false` otherwise.

Distance(Vector3)

Returns the Euclidean distance from point to the capsule's surface. Returns zero if point is inside or on the boundary.

Declaration

public readonly float Distance(Vector3 point)

Parameters

Type	Name	Description
Vector3	point	The query point in world space.

Returns

Type	Description
float	A non-negative distance in world units. Zero indicates the point is inside or touching the capsule.

Equals(Capsule3D)

Returns true if this capsule and other are approximately equal, comparing each component of PointA, PointB, and Radius using Approximately(float, float, float).

Declaration

public readonly bool Equals(Capsule3D other)

Parameters

Type	Name	Description
Capsule3D	other	The capsule to compare against.

Returns

Type	Description
bool	`true` if all seven float components are within EPSILON of each other; `false` otherwise.

Equals(object)

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
object	obj

Returns

Type	Description
bool

Overrides

ValueType.Equals(object)

FromAxisAligned(Vector3, Vector3, float, float)

Builds a capsule centered at center and oriented along axis, with the given total height (including both end-caps) and radius. The supplied axis is normalized before use; a zero-length axis falls back to UnityEngine.Vector3.up.

Declaration

public static Capsule3D FromAxisAligned(Vector3 center, Vector3 axis, float height, float radius)

Parameters

Type	Name	Description
Vector3	center	The center of the capsule (midpoint of the central segment).
Vector3	axis	The desired orientation of the capsule's long axis. Normalized internally; does not need to be unit length. A zero vector falls back to UnityEngine.Vector3.up.
float	height	The total height of the capsule including both hemispherical caps. Values smaller than `2 * radius` clamp the segment length to zero, producing a sphere.
float	radius	The radius of the capsule in world units. Should be non-negative.

Returns

Type	Description
Capsule3D	A new Capsule3D with end-points placed symmetrically around `center` along `axis`.

GetHashCode()

Declaration

public override int GetHashCode()

Returns

Type	Description
int

Overrides

ValueType.GetHashCode()

Intersects(in Capsule3D)

Returns true if this capsule overlaps other. The test compares the closest distance between the two central segments against the sum of both radii.

Declaration

public readonly bool Intersects(in Capsule3D other)

Parameters

Type	Name	Description
Capsule3D	other	The capsule to test against.

Returns

Type	Description
bool	`true` if the two capsule volumes share any point (including boundary contact); `false` if they are completely separated.

Remarks

Uses the segment-segment distance algorithm from Christer Ericson's "Real-Time Collision Detection" section 5.1.9. Degenerate cases (point-like segments) are handled without division by zero.

Intersects(in Sphere3D)

Returns true if this capsule overlaps sphere. The test compares the distance from the sphere's center to the capsule's central segment against the sum of both radii.

Declaration

public readonly bool Intersects(in Sphere3D sphere)

Parameters

Type	Name	Description
Sphere3D	sphere	The sphere to test against.

Returns

Type	Description
bool	`true` if the capsule and sphere volumes share any point (including boundary contact); `false` if they are completely separated.

ToAABB3D()

Returns the axis-aligned bounding box that encloses this capsule. The box is computed by taking the component-wise minimum and maximum of the two end-points and expanding by Radius on all sides.

Declaration

public readonly AABB3D ToAABB3D()

Returns

Type	Description
AABB3D	An AABB3D that tightly encloses the capsule's full volume, including both hemispherical end-caps.

ToString()

Returns a human-readable string representation of this capsule in the format Capsule3D[A=(x,y,z), B=(x,y,z), Radius=r].

Declaration

public override string ToString()

Returns

Type	Description
string	A formatted string describing the capsule's end-points and radius.

Overrides

ValueType.ToString()

Operators

operator ==(Capsule3D, Capsule3D)

Approximate equality operator. Delegates to Equals(Capsule3D); two capsules that differ only by floating-point rounding are considered equal.

Declaration

public static bool operator ==(Capsule3D left, Capsule3D right)

Parameters

Type	Name	Description
Capsule3D	left	The left operand.
Capsule3D	right	The right operand.

Returns

Type	Description
bool	`true` if the capsules are approximately equal; `false` otherwise.

operator !=(Capsule3D, Capsule3D)

Approximate inequality operator. Returns the negation of operator ==(Capsule3D, Capsule3D).

Declaration

public static bool operator !=(Capsule3D left, Capsule3D right)

Parameters

Type	Name	Description
Capsule3D	left	The left operand.
Capsule3D	right	The right operand.

Returns

Type	Description
bool	`true` if the capsules are not approximately equal; `false` otherwise.

Implements

IEquatable<T>