Class Shape

Namespace

Jitter2.Collision.Shapes

Assembly

Jitter2.dll

The main entity of the collision system. Implements ISupportMappable for narrow-phase and IDynamicTreeProxy for broad-phase collision detection. The shape itself does not have a position or orientation. Shapes can be associated with instances of RigidBody.

public abstract class Shape : IDynamicTreeProxy, IPartitionedSetIndex, IUpdatableBoundingBox, ISupportMappable, IRayCastable, ISweepTestable, IDistanceTestable

Inheritance

object

Shape

Implements

IDynamicTreeProxy

IPartitionedSetIndex

IUpdatableBoundingBox

ISupportMappable

IRayCastable

ISweepTestable

IDistanceTestable

Derived

RigidBodyShape

SoftBodyShape

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Fields

ShapeId

A 64-bit integer representing the shape ID. This is used by algorithms that require arranging shapes in a well-defined order.

public readonly ulong ShapeId

Field Value

ulong

Properties

Velocity

Gets the velocity of the entity, used for bounding box expansion.

[ReferenceFrame(ReferenceFrame.World)]
public abstract JVector Velocity { get; }

Property Value

JVector

WorldBoundingBox

The bounding box of the shape in world space. It is automatically updated when the position or orientation of the corresponding instance of RigidBody changes.

public JBoundingBox WorldBoundingBox { get; protected set; }

Property Value

JBoundingBox

Methods

Distance<T>(in T, in JQuaternion, in JVector, out JVector, out JVector, out JVector, out float)

Finds the closest points between this object and the query shape.

[ReferenceFrame(ReferenceFrame.World)]
public abstract bool Distance<T>(in T support, in JQuaternion orientation, in JVector position, out JVector pointA, out JVector pointB, out JVector normal, out float distance) where T : ISupportMappable

Parameters

support T

The query shape.

orientation JQuaternion

The query shape orientation in world space.

position JVector

The query shape position in world space.

pointA JVector

Closest point on the query shape in world space. Undefined when the shapes overlap.

pointB JVector

Closest point on this object in world space. Undefined when the shapes overlap.

normal JVector

Unit direction from the query shape toward this object, or Zero when the shapes overlap. Do not use this to test whether a result was found.

distance float

The separation distance between the shapes. Zero when overlapping.

Returns

bool

true if the shapes are separated; false if they overlap.

Type Parameters

T

The query support-map type.

GetCenter(out JVector)

Computes a point deep within the shape, used as an initial search point in GJK-based algorithms.

[ReferenceFrame(ReferenceFrame.Local)]
public abstract void GetCenter(out JVector point)

Parameters

point JVector

A point guaranteed to be inside the convex hull, typically the center of mass.

RayCast(in JVector, in JVector, out JVector, out float)

Performs a ray cast against this object.

[ReferenceFrame(ReferenceFrame.World)]
public abstract bool RayCast(in JVector origin, in JVector direction, out JVector normal, out float lambda)

Parameters

origin JVector

The starting point of the ray.

direction JVector

The direction of the ray. Does not need to be normalized.

normal JVector

The surface normal at the intersection point, or Zero if the ray origin is inside the object. Use the return value, not this parameter, to test whether a hit occurred.

lambda float

The distance along the ray to the intersection: hitPoint = origin + lambda * direction. Zero when the ray origin is inside the object.

Returns

bool

true if the ray intersects with the object; otherwise, false. Also returns true when the ray origin is inside the object, with lambda set to zero and normal set to Zero.

SupportMap(in JVector, out JVector)

Computes the point on the shape that is furthest in the specified direction.

[ReferenceFrame(ReferenceFrame.Local)]
public abstract void SupportMap(in JVector direction, out JVector result)

Parameters

direction JVector

The search direction in local space. Does not need to be normalized.

result JVector

The point on the shape's surface furthest along direction.

Sweep<T>(in T, in JQuaternion, in JVector, in JVector, out JVector, out JVector, out JVector, out float)

Performs a sweep test against this object.

[ReferenceFrame(ReferenceFrame.World)]
public abstract bool Sweep<T>(in T support, in JQuaternion orientation, in JVector position, in JVector sweep, out JVector pointA, out JVector pointB, out JVector normal, out float lambda) where T : ISupportMappable

Parameters

support T

The query shape.

orientation JQuaternion

The query shape orientation in world space.

position JVector

The query shape position in world space.

sweep JVector

The query shape translation in world space.

pointA JVector

Collision point on the query shape in world space at the sweep origin. Undefined when the shapes already overlap.

pointB JVector

Collision point on this object in world space at the sweep origin. Undefined when the shapes already overlap.

normal JVector

Collision normal in world space, or Zero if the shapes already overlap. Use the return value to determine whether a hit occurred; do not rely on this being non-zero.

lambda float

The time of impact expressed in units of sweep. Zero if the shapes already overlap.

Returns

bool

true if the query shape hits or already overlaps this object; otherwise, false.

Type Parameters

T

The query support-map type.

SweptExpandBoundingBox(float)

protected void SweptExpandBoundingBox(float dt)

Parameters

dt float

UpdateWorldBoundingBox(float)

Recomputes the world-space bounding box.

[ReferenceFrame(ReferenceFrame.World)]
public abstract void UpdateWorldBoundingBox(float dt = 0)

Parameters

dt float

The timestep for velocity-based expansion. Default is zero.