TreeAlpha Class Reference

A simple field function scaling node. More...

#include <blobtree.h>

Inheritance diagram for TreeAlpha:

Public Member Functions
	TreeAlpha (const double &, TreeNode *)
	Creates an alpha field function scaling node given one of child node.
virtual	~TreeAlpha ()
	Recursively destroys an alpha node.
double	Intensity (const Vector &) const
	Compute the field value at a given point in space.
Vector	Gradient (const Vector &) const
	Compute the gradient of the field function at a given point in space.
virtual TreeNode *	Copy () const
	Creates a deep copy of the node.
double	K () const
	Computes the gradient Lipschitz constant of the sub-tree.
double	K (const Box &) const
	Compute the local Lipschitz constant in a box.
double	K (const Ray &) const
	Computes the Lipschitz constant along a ray.
double	K (const Segment &) const
	Computes the Lipschitz constant.
double	K (const Sphere &) const
	Computes the Lipschitz constant.
Color	GetMaterial (const Vector &, const Vector &=Vector::Null) const
	Computes the texture of an alpha-node. Simply scales the texture parameters.
TreeNode *	Cut (const Box &) const
	Cuts the node to simplify its structure inside a box.
virtual int	Memory () const
	Compute the size of the sub-tree.
virtual TreeNode *	Alpha (const double &)
	Scale the scalar field by a given real value.
Public Member Functions inherited from TreeUnary
	TreeUnary (TreeNode *)
	Create a generic warping node.
virtual	~TreeUnary ()
	Recursively destroys the structure.
virtual int	Nodes () const
	Compute the number of nodes of the sub-tree.
virtual int	Depth () const
	Compute the dpeth of the sub-tree.
virtual void	SetThreshold (const double &)
	Recursively setup the threshold value.
Public Member Functions inherited from TreeOperator
	TreeOperator ()
	Creates an operator node.
virtual	~TreeOperator ()
	Destroys an operator.
Public Member Functions inherited from TreeNode
	TreeNode ()
	Create a virtual node of the Blob-Tree structure.
virtual	~TreeNode ()
	Destroys a node.
virtual double	Omega (const Vector &) const
	Return the squared distance to the compact support of the node.
virtual void	IntensityGradient (const Vector &, double &, Vector &) const
	Computes the field value and the gradient at a given point in space.
virtual TreeNode *	Blend (TreeNode *)
	Insert a blending node that blends the old and the new sub-tree together.
virtual TreeNode *	Union (TreeNode *)
	Insert a union node that unions the old and the new sub-tree together.
virtual TreeNode *	Difference (TreeNode *)
	Insert a difference node.
virtual TreeNode *	Translate (const Vector &)
	Insert a translation node.
virtual TreeNode *	Rotate (const Matrix &)
	Insert a rotation node.
virtual TreeNode *	Scale (const Vector &)
	Insert a scaling node.
virtual double	K (const RayStep &) const
	Compute the Lipschitz constant along an optimized ray-stepping segment.
Box	GetBox () const
	Return the bounding box of the node.
virtual QString	Show (int=0) const
	Show the tree hierarchy.
virtual Vector	Dichotomy (Vector, Vector, double, double, double, const double &=1.0e-4)
	Compute the intersection between the implicit surface and a segment.

Protected Attributes
double	alpha = 1.0
	Scaling coefficient.
Protected Attributes inherited from TreeNode
Box	box = Box::Null
	Bounding box of the node.
double	T = 0.5
	Threshold value.

Additional Inherited Members
Static Protected Attributes inherited from TreeNode
static const double	Epsilon = 1e-6
	Epsilon value for gradient computation.

Detailed Description

A simple field function scaling node.

The field of the child node is scaled by a constant scaling factor.

Note that this operation is different than scaling the primitive with a TreeFrame node, which scales the geometry instead.

This node is usefull when performing cross-dissolving effects between two models.

Implementaiton note: since the node shares exactly the same box as its sub-tree, we do not perform box checks in member functions; they will be done by the sub-tree.

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Constructor & Destructor Documentation

TreeAlpha()

TreeAlpha::TreeAlpha	(	const double &	a,
		TreeNode *	node )

Creates an alpha field function scaling node given one of child node.

Parameters

a	Alpha coefficient.
node	Child node.

Member Function Documentation

Gradient()

Vector TreeAlpha::Gradient ( const Vector & p ) const

virtual

Compute the gradient of the field function at a given point in space.

Parameters

p

Point.

Reimplemented from TreeNode.

K() [1/5]

double TreeAlpha::K ( ) const

virtual

Computes the gradient Lipschitz constant of the sub-tree.

The Lipschitz constant is simply scaled by the absolute value of alpha.

Implements TreeNode.

K() [2/5]

double TreeAlpha::K ( const Box & b ) const

virtual

Compute the local Lipschitz constant in a box.

Implements TreeNode.

K() [3/5]

double TreeAlpha::K ( const Ray & ray ) const

virtual

Computes the Lipschitz constant along a ray.

Parameters

ray

The ray.

Implements TreeNode.

K() [4/5]

double TreeAlpha::K ( const Segment & segment ) const

virtual

Computes the Lipschitz constant.

Parameters

segment

The segment.

Reimplemented from TreeNode.

K() [5/5]

double TreeAlpha::K ( const Sphere & s ) const

virtual

Computes the Lipschitz constant.

Parameters

s	The sphere.

Reimplemented from TreeNode.

GetMaterial()

Color TreeAlpha::GetMaterial ( const Vector & p, const Vector & n = Vector::Null ) const

virtual

Computes the texture of an alpha-node. Simply scales the texture parameters.

Parameters

p	Point.
n	Normal.

Reimplemented from TreeNode.

Cut()

TreeNode * TreeAlpha::Cut ( const Box & b ) const

virtual

Cuts the node to simplify its structure inside a box.

Parameters

b

The box.

Implements TreeNode.

Alpha()

TreeNode * TreeAlpha::Alpha ( const double & a )

virtual

Scale the scalar field by a given real value.

Parameters

a	Scalar value.