GeRayCollider Class Reference

#include <lib_collider.h>

Detailed Description

Ray collider engine : evaluates intersections between a ray and a single polygon object. The polygons are split into two triangles each when calculating the intersections, thus affecting the intersection count when the invisible shared edges are hit. The original polygon object remains unmodified.

Note

Has to be created with Alloc() and destroyed with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

Public Member Functions
Bool	Init (const BaseObject *goal, Bool force=false)
Bool	Intersect (const Vector &ray_p, const Vector &ray_dir, Float ray_length, Bool only_test=false)
Int32	GetIntersectionCount ()
Bool	GetIntersection (Int32 number, GeRayColResult *res)
Bool	GetNearestIntersection (GeRayColResult *res)

Static Public Member Functions
static GeRayCollider *	Alloc ()
static void	Free (GeRayCollider *&data)

Private Member Functions
	GeRayCollider ()
	~GeRayCollider ()

Constructor & Destructor Documentation

GeRayCollider()

GeRayCollider ( )

private

~GeRayCollider()

~GeRayCollider ( )

private

Member Function Documentation

Alloc()

static GeRayCollider* Alloc ( )

static

Allocates a ray collider engine. Destroy the allocated ray collider engine with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

Returns

The allocated ray collider engine, or nullptr if the allocation failed.

Free()

static void Free ( GeRayCollider *&  data )

static

Destructs ray collider engines allocated with Alloc(). Use AutoAlloc to automate the allocation and destruction based on scope.

Parameters

[in,out]

data

The ray collider engine to destruct. If the pointer is nullptr nothing happens. The pointer is assigned nullptr afterwards.

Init()

Bool Init	(	const BaseObject *	goal,
		Bool	force = false
	)

Initializes the ray collider with the object specified by goal.

Parameters

[in]	goal	The object to check for intersections. The pointed object is copied.
[in]	force	If false then Cinema 4D checks if the passed object's GetDirty(DIRTYFLAGS::DATA) is unchanged. If yes, it does nothing and returns true. If true it always rebuilds the cache.

Returns

true if successful, otherwise false.

Intersect()

Bool Intersect	(	const Vector &	ray_p,
		const Vector &	ray_dir,
		Float	ray_length,
		Bool	only_test = false
	)

Checks if the line segment specified by ray_p to ray_p + ray_dir*ray_length intersects the object.
If only_test is false the intersections can be evaluated with GetIntersectionCount() and GetIntersection().

Parameters

[in]	ray_p	The start point of the ray in object coordinates.
[in]	ray_dir	The ray direction in object coordinates.
[in]	ray_length	The ray length.
[in]	only_test	If true no information about the intersections are stored, so only the return value can be used to tell if there were intersections or not.

Returns

true if there was an intersection, otherwise false.

GetIntersectionCount()

Int32 GetIntersectionCount

(

)

Retrieves the number of intersections found by Intersect(), which is in terms of the amount of triangles hit by the ray. Intersecting a shared edge will result in a value greater than one. Intersecting a shared edge point will result in a value that varies depending on how the polygon object is split up into triangles.

Returns

The number of intersections.

GetIntersection()

Bool GetIntersection	(	Int32	number,
		GeRayColResult *	res
	)

Retrieves intersections, found with Intersect(), by index.

Parameters

[in]	number	The intersection index: 0 <= number < GetIntersectionCount()
[out]	res	Assigned the intersection information. The caller owns the pointed GeRayColResult.

Returns

true if successful, otherwise false.

GetNearestIntersection()

Bool GetNearestIntersection

(

GeRayColResult *

res

)

Retrieves the intersection, found with Intersect(), closest to the start of the ray.

Parameters

[in]

res

Assigned the intersection information. The caller owns the pointed GeRayColResult.

Returns

true if successful, otherwise false.