Collider

---

A collider is a collision shape that is used for physics simulation and it is attached to a PhysicObject (its root). Colliders are invisible, and they do not necessary need to exactly match the object you want to include in the physics simulation; it can simply be an rough approximation of it, consequently it will be unnoticeable at runtime (also more efficient for the CPU).

When creating a new Collider you will be asked to select a CollisionBounds; which range from simple shapes like a Cube or a Sphere to more complex and precise shapes including Triangle Mesh or ConvexHull. The more complex the collision bounds is the more demanding it will be for the physics simulation to process them.

Multiple basic shapes can also be combined to create more complex shape; it is called a Compound Shape. Using a compound shape is ideal to approximate complex objects using multiple simple shapes.

See Also

PhysicObject, RigidBody, Geometry, Mesh, PhysicMaterial, World

Static Variables

---

Name	Description
physicobject	The parent PhysicObject that Collider is associated with.
Declaration PhysicObject *physicobject
data	Access the settings and properties for the active type of collider's CollisionBounds.
Declaration ColliderData data
physicmaterial_count	The amount of PhysicMaterial the collider contains.
Declaration unsigned short physicmaterial_count Attention Only the CollisionBounds type kTriangleMesh can have multiple PhysicMaterial attached; one for each primitive the specified geometry connected to the Collider contains.
uid	Unique universal id to identify the Collider.
Declaration unsigned int uid

Variables

---

Name	Description
name	Unique name to identify the Collider from its parent PhysicObject.
Declaration char *name
margin	Controls the margin of the Collider improving stability by reducing penetration.
Declaration float margin Range 0.0 to 1.0
local_matrix	4x4 matrix that contains the local Collider transformation.
Declaration mat4 local_matrix
dynamic	Force the Collider to be updated using its parent Object bounds to dynamically adjust the collider at runtime.
Declaration bool dynamic Remarks This option is mostly used when you are using a primitive collision shape (ie: a Capsule) on an animated Object (ie: a SkeletalMesh). Settings this variable to true will force the capsule to shrink or grow depending on the size of the Object connected to the PhysicObject, parent to the Collider.

Functions

---

Name	Description
SetPhysicMaterial	Set a PhysicMaterial to a specific primitive slot index.
Declaration bool SetPhysicMaterial( unsigned short primitive_index, PhysicMaterial *physicmaterial ) Parameters primitive_index: Primitive slot index to used to assign the PhysicMaterial. physicmaterial: An existing PhysicMaterial asset or simply use nil to disconnect. Return Value true if the primitive_index parameter point to an existing slot; else return false. Note Setting multiple PhysicMaterial is mostly useful when dealing with a kTriangleMesh. You can use different PhysicMaterial to simulate smooth friction transition between from (ie.) mud to grass to ice etc...
GetPhysicMaterial	Retrive the PhysicMaterial connected to a specific primitive slot.
Declaration PhysicMaterial *GetPhysicMaterial( unsigned short primitive_index ) Parameters primitive_index: The primitive index you wish to retrieve the PhysicMaterial connected to it. Return Value nil if the primitive_index does not exist or if the slot does not have any PhysicMaterial connected to it.
SetGeometry	Set an existing geometry to use for the active Collider.
Declaration bool SetGeometry( const char *name ) Parameters name: Specify an existing Mesh asset name to directly access and use its Geometry for the active Collider. Return Value true if the Geometry have been successfully connected. Return false if the Geometry (mesh asset name) does not exist or if the CollisionBounds of the collider is not kTriangleMesh or kConvexHull.
Update	Manually trigger a Collider update.
Declaration void Update( void )

CollisionBounds

---

The list below contains all types of collision shape a Collider can be created with (one type per Collider). Ranging from fast basic primitive shapes to more precise, complex and demanding (CPU intensive).

• kBox: Use a box shape to define the collision shape.
• kSphere: Spherical collision shape.
• kCylinder: Cylindrical collision shape.
• kCapsule: Similar as cylinder at the exception that the caps are represented as hemispheres.
• kCone: Conical collision shape representation.
• kConvexHull: Use the geometry vertices to approximate a tri-dimensional hull to define the collision shape.
• kTriangleMesh: Use the actual geometry triangles to define the collision shape.

BoxCollider

---

Box shape collision bounds.

Variables

---

Name	Description
size	Define the size of the box all axes.
Declaration vec3 size
margin	The inner section of the box collider (Region only).
Declaration vec3 margin

SphereCollider

---

Spherical shaped collision bounds.

Variables

---

Name	Description
radius	The dimension of the sphere radius.
Declaration float radius
margin	The inner section of the sphere collider (Region only).
Declaration float margin

CylinderCollider

---

Cylindrical shaped collision bounds.

Variables

---

Name	Description
height	The height of the cylinder.
Declaration float height
radius	Defines the radius of the cylinder.
Declaration float radius
margin	The inner section of the Cylinder collider (Region only).
Declaration vec2 margin Note The X axis represent the margin for the height and the Y axis is the axis for the radius margin.

CapsuleCollider

---

Capsule shape collision bounds.

Variables

---

Name	Description
height	Defines the height of the capsule.
Declaration float height
radius	Specify the capsule's radius.
Declaration float radius

ConeCollider

---

Cone shape collision bounds.

Variables

---

Name	Description
height	The height of the cone collision shape.
Declaration float height
radius	Controls the size of the base radius of the cone.
Declaration float radius

TriangleMeshCollider

---

Collision shape that uses the triangle information of an existing Mesh Geometry.

Static Variables

---

Name	Description
geometry	Internal geometry used by the triangle mesh collider.
Declaration Geometry *geometry

Variables

---

Name	Description
compression	Enable or disable quantized AABB compression.
Declaration bool compression

ConvexHullCollider

---

Use an existing Mesh Geometry vertices to create a 3d hull.

Static Variables

---

Name	Description
geometry	The internal geometry used by the convex hull.
Declaration Geometry *geometry

Variables

---

Name	Description
reduction	Enable or disable vertex reduction.
Declaration bool reduction Note If reduction is turned off all vertices of the geometry will be used to generate the convex hull. It is more precise but require more processing. When reduction is enabled, the system will create an approximated version of the geometry outline using the outmost vertices.

ColliderData

---

Accessible via the data member variable of the Collider. This field gives you access to all settings and properties for the CollisionBounds type you used to create your Collider.

Static Variables

---

Name	Description
type	The type of CollisionBounds currently in use by the Collider.
Declaration CollisionBounds type
box	Box collider properties.
Declaration BoxCollider *box Remarks Only available if the collider have been created using the CollisionBounds kBox; else return nil.
sphere	Sphere collider properties.
Declaration SphereCollider *sphere Remarks Only available if the collider have been created using the CollisionBounds kSphere; else return nil.
cylinder	Cylinder collider properties.
Declaration CylinderCollider *cylinder Remarks Only available if the collider have been created using the CollisionBounds kCylinder; else return nil.
capsule	Capsule collider properties.
Declaration CapsuleCollider *capsule Remarks Only available if the collider have been created using the CollisionBounds kCapsule; else return nil.
cone	Cone collider properties.
Declaration ConeCollider *cone Remarks Only available if the collider have been created using the CollisionBounds kCone; else return nil.
trianglemesh	TriangleMesh collider properties.
Declaration TriangleMeshCollider *trianglemesh Remarks Only available if the collider have been created using the CollisionBounds kTriangleMesh; else return nil.
convexhull	ConvexHull collider properties.
Declaration ConvexHullCollider *convexhull Remarks Only available if the collider have been created using the CollisionBounds kConvexHull; else return nil.