#include <lib_splinehelp.h>

Detailed Description

Class for helping to deal with splines. Defines routines to get positions along splines from real-world units, non flipping/non gimbal locked matrices and vectors from splines.
Must be initialized before use. All values returned are in global space. The slow part is the InitSpline() routine; other access is pretty fast.

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

Private Member Functions
	SplineHelp ()

	~SplineHelp ()

Alloc/Free
static SplineHelp *	Alloc ()

static void	Free (SplineHelp *&node)

Init/Free Spline
Bool	InitSplineEx (BaseObject op, Vector upvector=Vector(0.0), BaseObject rail=nullptr, Bool target_rail=true, Bool use_deformed_points=false, Bool force_update=false, Bool use_global_space=true)

void	FreeSpline ()

Bool	InitSpline (BaseObject *op, SPLINEHELPFLAGS flags=SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE)

Bool	InitSpline (BaseObject *op, Vector upvector, SPLINEHELPFLAGS flags=SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE)

Bool	InitSpline (BaseObject op, BaseObject rail, SPLINEHELPFLAGS flags=SPLINEHELPFLAGS::TARGETRAIL\|SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE)

Count
Int32	GetSegmentCount ()

Int32	GetVertexCount (Int32 segment=NOTOK)

Int32	GetPointCount ()

Operations
Float	GetSplineLength ()

Float	GetSegmentLength (Int32 segment)

Matrix	GetVertexMatrix (Int32 index)

Float	GetPointValue (Float offset, Int32 segment)

Int32	GetPointIndex (Float offset, Int32 segment)

Vector	GetPosition (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

Vector	GetTangent (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

Vector	GetNormal (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

Vector	GetCrossNormal (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

Float	GetOffsetFromUnit (Float unitoffset, Int32 segment=0)

Float	GetOffsetFromReal (Float offset, Int32 segment=0)

Matrix	GetMatrix (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

void	GetLinePointSegment (Int32 index, Float offset, Int32 ind, Int32 *segment)

void	GetSplinePointSegment (Int32 index, Float offset, Int32 ind, Int32 *segment)

void	GlobalToLocal (Float offset, Float off, Int32 segment, Bool realoffset=false)

Int32	SplineToLineIndex (Int32 index)

Int32	LineToSplineIndex (Int32 index)

Float	GetSize (Float offset, Int32 segment=0, Bool smooth=true, Bool realoffset=false)

Float	GetVertexSize (Int32 index)

Matrix	GetVertexMatrix (Int32 segment, Int32 index)

Miscellaneous
Bool	CopyTo (SplineHelp *dest) const

Bool	Exists ()

Bool	IsClosed (Int32 segment=0)

SPLINETYPE	GetType ()

void	SetOwner (BaseObject *op)

UInt32	GetDirty () const

Matrix	GetPointMatrix (Int32 splineVertexIndex)

LineObject *	GetLineObject ()

SplineObject *	GetSplineObjectCache ()

Constructor & Destructor Documentation

◆ SplineHelp()

SplineHelp ( )

private

◆ ~SplineHelp()

~SplineHelp ( )

private

Member Function Documentation

◆ Alloc()

static SplineHelp* Alloc ( )

static

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

Returns: The allocated spline help, or nullptr if the allocation failed.

◆ Free()

static void Free ( SplineHelp *& node )

static

Destructs spline help instances allocated with Alloc(). Use AutoAlloc to automate the allocation and destruction based on scope.

Parameters

[in] node The spline help to destruct. If the pointer is nullptr nothing happens. The pointer is assigned nullptr afterwards.

◆ InitSplineEx()

Bool InitSplineEx	(	BaseObject *	op,
		Vector	upvector = `Vector(0.0)`,
		BaseObject *	rail = `nullptr`,
		Bool	target_rail = `true`,
		Bool	use_deformed_points = `false`,
		Bool	force_update = `false`,
		Bool	use_global_space = `true`
	)

Initializes the spline data. Deprecated since R17.

Warning: Must be called before any other access.

Parameters

[in]	op	The spline object to use. The caller owns the pointed spline object.
[in]	upvector	An optional up-vector for the spline normals generation. This is only used at the start of splines/segments; this way it avoids gimbal lock if at all possible.
[in]	rail	An optional rail spline object for the spline normals generation. The caller owns the pointed spline object.
[in]	target_rail	If true the optional rail spline is not only used as up-vector but also as target. This is used for instance in MoGraph's Rail options (Cloner, Spline effector, Spline Wrap etc.).
[in]	use_deformed_points	If true uses the deformed point positions of the spline.
[in]	force_update	If true forces a full initialization. The spline help class internally caches its own content. Thus it will be much faster if the same splines are used for initialization. .
[in]	use_global_space	If false the resulting matrices are in local space rather than in the spline objects' global space.

Returns: true if successful, otherwise false.

◆ FreeSpline()

void FreeSpline ( )

Frees the spline data. Recalling InitSpline() or calling Free() will automatically call this.

◆ GetSegmentCount()

Int32 GetSegmentCount ( )

Gets the number of segments in the spline.

Note: Unlike the way Cinema 4D handles segments where a segment count of 0 means there is either no segments or 1 segment, this returns 1 segment if there is 1 and 0 if there are 0.

Returns: The segment count.

◆ GetVertexCount()

Int32 GetVertexCount ( Int32 segment = NOTOK )

Gets the number of vertices for a spline segment.

Parameters

[in] segment The segment index: 0 <= segment < GetSegmentCount()

Returns: The number of vertices.

◆ GetPointCount()

Int32 GetPointCount ( )

Retrieves the number of spline points.

Returns: The number of spline points.

◆ GetSplineLength()

Float GetSplineLength ( )

Retrieves the spline's real-world unit length including all segments.

Returns: The spline length.

◆ GetSegmentLength()

Float GetSegmentLength ( Int32 segment )

Retrieves a specific segment's real-world unit length.

Parameters

[in] segment The segment index: 0 <= segment < GetSegmentCount()

Returns: The length of the specified segment.

◆ GetVertexMatrix() [1/2]

Matrix GetVertexMatrix ( Int32 index )

Retrieves a full matrix for a specific point of the line.

Note: This is not the spline vertex, but instead the line object's vertex. (Calculated with LOD = 1.0.)

Parameters

[in] index The index of the line object vertex: 0 <= index < op->GetPointCount()

Returns: The coordinate system matrix at index.

◆ GetPointValue()

Float GetPointValue	(	Float	offset,
		Int32	segment
	)

Converts a natural offset value to a real percentage offset value.

Note: The percentage uses the real-world units for its offset, so regardless of how the spline's points and interpolation is set, a gap of 2% on a 100m long spline will always be 2m whereas normally in spline natural space, a gap of 2% can vary a great deal depending on the spline's interpolation etc.

Parameters

[in]	offset	The offset given in spline space.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()

Returns: The real-world percentage offset.

◆ GetPointIndex()

Int32 GetPointIndex	(	Float	offset,
		Int32	segment
	)

Retrieves the nearest line point index to the given real offset.

Parameters

[in]	offset	The spline space offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()

Returns: The nearest line object point index, rounded down.

◆ GetPosition()

Vector GetPosition	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Gets a position along the spline.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The position given by offset in global space.

◆ GetTangent()

Vector GetTangent	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Gets a tangent vector for any point along the spline.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The tangent given by offset in global space.

◆ GetNormal()

Vector GetNormal	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Gets a normal vector for any point along the spline.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The normal given by offset in global space.

◆ GetCrossNormal()

Vector GetCrossNormal	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Gets a cross normal vector (i.e. perpendicular to the normal and the tangent) for any point along the spline.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The cross normal given by offset in global space.

◆ GetOffsetFromUnit()

Float GetOffsetFromUnit	(	Float	unitoffset,
		Int32	segment = `0`
	)

Converts a percentage offset into a natural offset. Percentage offsets ignore spline interpolation etc and are always x% along the spline.

Parameters

[in]	unitoffset	A percentage offset: 0 <= unitoffset <= 1.0.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()

Returns: The natural offset.

◆ GetOffsetFromReal()

Float GetOffsetFromReal	(	Float	offset,
		Int32	segment = `0`
	)

Retrieves an offset from a real-world unit.
For example, if a spline is 50 units long, 25 would be 50% of the length, i.e. 0.5.

Parameters

[in]	offset	The real unit offset to convert.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()

Returns: The offset in spline space.

◆ GetMatrix()

Matrix GetMatrix	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Retrieves a full matrix for any point along the spline, constructed as a local coordinate system at that point.
Optionally uses real-world percentage rather than spline natural space for the offset.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The coordinate system matrix at offset.

◆ GetLinePointSegment()

void GetLinePointSegment	(	Int32	index,
		Float *	offset,
		Int32 *	ind,
		Int32 *	segment
	)

Converts a global point index in a line (i.e. from 0 to the number of points in the line object) to a local set of values within a single segment returning the segment the point is in, the offset along the segment and the point index within the segment (0 to the segment point count).

Parameters

[in]	index	The line object vertex index: 0 <= index < op->GetPointCount() (Using LOD = 1.0 for the line object.)
[out]	offset	Assigned the offset along the segment.
[out]	ind	Assigned the point index within the segment.
[out]	segment	Assigned the segment index.

◆ GetSplinePointSegment()

void GetSplinePointSegment	(	Int32	index,
		Float *	offset,
		Int32 *	ind,
		Int32 *	segment
	)

Converts a global point index in (i.e. from 0 to the number of points in the spline) to a local set of values within a single segment returning the segment the point is in, the offset along the segment and the point index within the segment (0 0 to the segment point count).

Note: This is the same as GetLinePointSegment(), but uses the spline's set of indexes.

Parameters

[in]	index	The global spline point index: 0 <= index < op->GetPointCount()
[out]	offset	Assigned the offset along the segment.
[out]	ind	Assigned the point index within the segment.
[out]	segment	Assigned the segment index.

◆ GlobalToLocal()

void GlobalToLocal	(	Float	offset,
		Float *	off,
		Int32 *	segment,
		Bool	realoffset = `false`
	)

Turns a percentage along the whole spline to local segment info, offset along segment, the segment the point exists in.
Optionally uses a real % offset rather than the spline natural offset.

Parameters

[in]	offset	The percentage along the whole spline.
[out]	off	Assigned the offset along the segment.
[out]	segment	Assigned the segment index.
[in]	realoffset	If true a real-world percentage is used, rather than the natural spline space.

◆ SplineToLineIndex()

Int32 SplineToLineIndex ( Int32 index )

Converts a spline vertex index to its corresponding line object vertex index.

Parameters

[in] index The spline vertex index: 0 <= index < op->GetPointCount()

Returns: The line object vertex index: 0 <= index < op->GetPointCount()

◆ LineToSplineIndex()

Int32 LineToSplineIndex ( Int32 index )

Converts a line object vertex index to its corresponding spline vertex index.

Parameters

[in] index The line object vertex index: 0 <= index < op->GetPointCount()

Returns: The spline vertex index: 0 <= index < op->GetPointCount()

◆ GetSize()

Float GetSize	(	Float	offset,
		Int32	segment = `0`,
		Bool	smooth = `true`,
		Bool	realoffset = `false`
	)

Gets the distance to an existing rail spline for any point along the spline.

Parameters

[in]	offset	The spline offset.
[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	smooth	If true the position is smoothed.
[in]	realoffset	If true uses uniform spline distribution.

Returns: The distance given by offset.

◆ GetVertexSize()

Float GetVertexSize ( Int32 index )

Gets the distance to an existing rail spline for a spline vertex specified by index.

Parameters

[in] index The vertex index: 0 <= index < GetVertexCount()

Returns: The distance given by index.

◆ GetVertexMatrix() [2/2]

Matrix GetVertexMatrix	(	Int32	segment,
		Int32	index
	)

Gets the matrix for a spline vertex specified by segment and index.

Parameters

[in]	segment	The segment index: 0 <= segment < GetSegmentCount()
[in]	index	The vertex index: 0 <= index < GetVertexCount()

Returns: The matrix given by segment and index.

◆ CopyTo()

Bool CopyTo ( SplineHelp * dest ) const

Copies the spline helper data to another SplineHelp.

Parameters

[in,out] dest The destination spline help. The caller owns the pointed spline help.

Returns: true if successful, otherwise false.

◆ Exists()

Bool Exists ( )

Checks if the spline helper contains data and has been initialized.

Returns: true if the spline helper is ready to use, otherwise false.

◆ IsClosed()

Bool IsClosed ( Int32 segment = 0 )

Checks if a spline segment is closed.

Parameters

[in] segment The segment index: 0 <= segment < GetSegmentCount()

Returns: true if the spline segment is closed, otherwise false.

◆ GetType()

SPLINETYPE GetType ( )

Retrieves the spline interpolation type.

Returns: The spline interpolation type: SPLINETYPE

◆ SetOwner()

void SetOwner ( BaseObject * op )

Prevents recursion lock crashes when SplineHelp needs to create the cache of the passed spline.
This is the case if for instance the developer has no control over the placement of a spline object in relation to its node.
For instance prevents infinite recursion in an object generator linking to itself using link fields.
Example:

class MyBaseObject : public ObjectData
{
  INSTANCEOF(MyBaseObject, ObjectData)
public:
  AutoAlloc<SplineHelp> shelp;
 
  virtual Bool Init(GeListNode *node)
  {
    if (!shelp)
      return false;
    shelp->SetOwner((BaseObject*)node);   // Only needs to be set once so NodeData::Init is a good place
 
    return true;
  }
 
  ...
 
  // In some other function
  if (shelp->InitSpline(spline))    // etc.
 
  ...
};

It is also possible to call

shelp->SetOwner(thisobject);

shelp->InitSpline(spline);

ObjectData::GetVirtualObjects() rather than in ObjectData::Init(). SetOwner() is not very costly to call.

Warning: Must be called before InitSpline().

Parameters

[in]

op

The object owning the current node data.
If called from within a tag plugin pass the tag's parent object:

shelp->SetOwner(tag->GetObject())

If called from within an object plugin use:

shelp->SetOwner((BaseObject*)node->Get())

◆ GetDirty()

UInt32 GetDirty ( ) const

Gets the dirty value for the SplineHelp which indicates how often the help has been updated with new values. i.e. how often the source spline has changed, and or the spline has been cleared.

Since: R17.032

Returns: The dirty checksum.

◆ GetPointMatrix()

Matrix GetPointMatrix ( Int32 splineVertexIndex )

Gets the matrix for a spline vertex.

Since: R17.032

Parameters

[in] splineVertexIndex The zero-based index of the spline vertex.

Returns: The resulting Matrix for that point along the spline.

◆ GetLineObject()

LineObject* GetLineObject ( )

Gets a LineObject from SplineHelp functions.

Warning: Call InitSpline() with SPLINEHELPFLAGS::RETAINLINEOBJECT for this method to return a line object.

Since: R17.032

Returns: The line object. nullptr if it fails or if the SplineHelp was not initialized with SPLINEHELPFLAGS::RETAINLINEOBJECT.

◆ GetSplineObjectCache()

SplineObject* GetSplineObjectCache ( )

Get the cached SplineObject. The SplineHelp owns the pointed SplineObject.

Note: Deformations are already computed on this SplineObject.

Warning: Call InitSpline() before.

Returns: The cache object. nullptr if it fails or if the SplineHelp was not initialized.

◆ InitSpline() [1/3]

Bool InitSpline	(	BaseObject *	op,
		SPLINEHELPFLAGS	flags = `SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE`
	)

Initializes the SplineHelp with the passed spline op, must be called before any other functions can be utilized.

Warning: Must be called before any other access.

Since: R17.032

Parameters

[in]	op	The spline object to initialize from. The caller owns the pointed spline object.
[in]	flags	The optional flags used to control how the SplineHelp is setup: SPLINEHELPFLAGS

Returns: true if the SplineHelp was successfully initialized, otherwise false.

◆ InitSpline() [2/3]

Bool InitSpline	(	BaseObject *	op,
		Vector	upvector,
		SPLINEHELPFLAGS	flags = `SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE`
	)

Initializes the SplineHelp with the passed spline op, must be called before any other functions can be utilized.

Warning: Must be called before any other access.

Since: R17.032

Parameters

[in]	op	The spline object to initialize from. The caller owns the pointed spline object.
[in]	upvector	The initial up-vector for the spline if no rail spline is passed.
[in]	flags	The optional flags used to control how the SplineHelp is setup: SPLINEHELPFLAGS

Returns: true if the SplineHelp was successfully initialized, otherwise false.

◆ InitSpline() [3/3]

Bool InitSpline	(	BaseObject *	op,
		BaseObject *	rail,
		SPLINEHELPFLAGS	flags = `SPLINEHELPFLAGS::TARGETRAIL\|SPLINEHELPFLAGS::GLOBALSPACE\|SPLINEHELPFLAGS::CONTINUECURVE`
	)

Initializes the SplineHelp with the passed spline op, must be called before any other functions can be utilized.

Warning: Must be called before any other access.

Since: R17.032

Parameters

[in]	op	The SplineObject to initialize from. The caller owns the pointed spline object.
[in]	rail	The rail spline. The caller owns the pointed spline object.
[in]	flags	The optional flags used to control how the SplineHelp is setup: SPLINEHELPFLAGS

Returns: true if the SplineHelp was successfully initialized, otherwise false.

Detailed Description

Private Member Functions

Alloc/Free

Init/Free Spline

Count

Operations

Miscellaneous

Constructor & Destructor Documentation

◆ SplineHelp()

◆ ~SplineHelp()

Member Function Documentation

◆ Alloc()

◆ Free()

◆ InitSplineEx()

◆ FreeSpline()

◆ GetSegmentCount()

◆ GetVertexCount()

◆ GetPointCount()

◆ GetSplineLength()

◆ GetSegmentLength()

◆ GetVertexMatrix() [1/2]

◆ GetPointValue()

◆ GetPointIndex()

◆ GetPosition()

◆ GetTangent()

◆ GetNormal()

◆ GetCrossNormal()

◆ GetOffsetFromUnit()

◆ GetOffsetFromReal()

◆ GetMatrix()

◆ GetLinePointSegment()

◆ GetSplinePointSegment()

◆ GlobalToLocal()

◆ SplineToLineIndex()

◆ LineToSplineIndex()

◆ GetSize()

◆ GetVertexSize()

◆ GetVertexMatrix() [2/2]

◆ CopyTo()

◆ Exists()

◆ IsClosed()

◆ GetType()

◆ SetOwner()

◆ GetDirty()

◆ GetPointMatrix()

◆ GetLineObject()

◆ GetSplineObjectCache()

◆ InitSpline() [1/3]

◆ InitSpline() [2/3]

◆ InitSpline() [3/3]