Struct Capsule 

pub struct Capsule {
    pub radius: Real,
    pub half_height: Real,
}

A capsule defined by radius and half-height along the Y axis.

Fields

radius: Real

Radius of the capsule end-caps.

half_height: Real

Half-height of the cylindrical segment.

Implementations

impl Capsule

pub fn new(radius: Real, half_height: Real) -> Self

Create a new capsule.

pub fn volume_explicit(&self) -> Real

Volume: cylinder + two hemisphere caps = πr²h + (4/3)πr³.

pub fn surface_area(&self) -> Real

Surface area: 2πrh (cylinder lateral) + 4πr² (two hemispheres).

pub fn inertia_tensor_array(&self, mass: f64) -> [[f64; 3]; 3]

Inertia tensor as [[f64;3\];3] row-major.

pub fn ray_cast_array( &self, origin: [f64; 3], direction: [f64; 3], max_toi: f64, ) -> Option<(f64, [f64; 3])>

Ray cast returning (t, normal) as plain arrays.

pub fn support(&self, direction: [f64; 3]) -> [f64; 3]

GJK support function: farthest point in direction.

pub fn closest_point(&self, p: [f64; 3]) -> [f64; 3]

Closest point on the capsule surface to point p.

pub fn contains_point(&self, p: [f64; 3]) -> bool

Returns true if p is inside (or on) the capsule.

pub fn signed_distance(&self, p: [f64; 3]) -> f64

Signed distance from a point to the capsule surface. Negative if inside, positive if outside.

pub fn medial_axis_endpoints(&self) -> ([f64; 3], [f64; 3])

Medial axis endpoints: the two centers of the hemispherical caps.

pub fn full_length(&self) -> f64

Full length of the capsule (tip to tip along Y).

pub fn medial_axis_length(&self) -> f64

Medial axis length (just the cylindrical segment).

pub fn segment_segment_distance( a0: [f64; 3], a1: [f64; 3], b0: [f64; 3], b1: [f64; 3], ) -> f64

Distance between two segments in 3D. Segment A: from a0 to a1, Segment B: from b0 to b1. Returns the minimum distance.

pub fn capsule_capsule_distance( &self, center_a: [f64; 3], other: &Capsule, center_b: [f64; 3], ) -> f64

Capsule-capsule distance. Both capsules are centered at the origin with Y-axis alignment, but offset by given centers. Returns the minimum distance between the two capsule surfaces (0 if overlapping).

pub fn capsule_capsule_overlap( &self, center_a: [f64; 3], other: &Capsule, center_b: [f64; 3], ) -> bool

Check if two capsules overlap.

pub fn project_on_medial_axis(&self, p: [f64; 3]) -> f64

Project a point onto the medial axis (the Y-axis segment). Returns the clamped Y value.

pub fn distance_to_medial_axis(&self, p: [f64; 3]) -> f64

Distance from a point to the medial axis.

pub fn inertia_tensor_raw(&self, mass: f64) -> [[f64; 3]; 3]

Inertia tensor (mass-normalized) returned as [[f64;3\];3] (identical to inertia_tensor_array but accepts mass separately for the public array API).

pub fn closest_points_capsule_vs_capsule( &self, center_a: [f64; 3], other: &Capsule, center_b: [f64; 3], ) -> ([f64; 3], [f64; 3], f64)

Closest points between two capsule medial axes (and thus capsule surfaces).

Returns (pa, pb, seg_dist) where pa and pb are the closest points on the respective medial axes and seg_dist is the axis-to-axis distance.

pub fn segment_segment_closest( a0: [f64; 3], a1: [f64; 3], b0: [f64; 3], b1: [f64; 3], ) -> ([f64; 3], [f64; 3], f64)

Returns the closest points on two 3D segments and the distance between them.

pub fn intersects_obb( &self, capsule_center: [f64; 3], obb_center: [f64; 3], obb_axes: [[f64; 3]; 3], obb_half: [f64; 3], ) -> bool

Capsule vs Oriented Bounding Box (OBB) intersection test.

obb_center: world-space center of the OBB. obb_axes: columns are the OBB’s local X, Y, Z axes (unit vectors). obb_half: half-extents along the OBB local axes.

Converts the query to OBB-local space and tests sphere-swept segment against the OBB using the separating-axis theorem (SAT) with slabs.

pub fn sdf(&self, p: [f64; 3]) -> f64

Signed distance field (SDF) for the capsule.

Same as signed_distance but with a different name to match the naming convention used in shader / SDF contexts.

pub fn swept_capsule_vs_sphere( &self, center_start: [f64; 3], center_end: [f64; 3], sphere_center: [f64; 3], sphere_radius: f64, ) -> Option<f64>

Continuous collision detection (swept capsule).

Given the capsule moving from center_start to center_end (linear motion, constant orientation), and a static sphere at sphere_center with sphere_radius, returns the first time of contact t ∈ [0,1] or None if no contact occurs.

This is a simple CCD sweep using the Minkowski-sum radius and a moving-segment vs static-point formulation.

pub fn random_surface_points(&self, n: usize, seed: u64) -> Vec<[f64; 3]>

Generate n random points on the capsule surface using rejection sampling.

Returns a Vec of [f64;3] coordinates sampled uniformly on the surface. Uses a deterministic PRNG seed for reproducibility.

pub fn capsule_triangle_contact( &self, center: [f64; 3], ta: [f64; 3], tb: [f64; 3], tc: [f64; 3], ) -> Option<(f64, [f64; 3])>

Test capsule vs a world-space triangle (ta, tb, tc).

The capsule is placed at center (Y-aligned). Returns Some((depth, normal)) if the capsule penetrates the triangle plane by at least depth > 0, where normal points from the triangle towards the capsule center.

Trait Implementations

impl Clone for Capsule

fn clone(&self) -> Capsule

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Capsule

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Shape for Capsule

fn bounding_box(&self) -> Aabb

Compute the axis-aligned bounding box of this shape (in local space).

fn support_point(&self, direction: &Vec3) -> Vec3

Compute the support point in the given direction (for GJK).

fn volume(&self) -> Real

Compute the volume of this shape.

fn center_of_mass(&self) -> Vec3

Compute the center of mass in local space.

fn inertia_tensor(&self, mass: Real) -> Mat3

Compute the inertia tensor for the given mass.

fn ray_cast( &self, ray_origin: &Vec3, ray_direction: &Vec3, max_toi: Real, ) -> Option<RayHit>

Cast a ray against this shape (in local space). Returns the first intersection within max_toi.

fn mass_properties(&self, density: Real) -> MassProperties

Compute full mass properties for a given density.