TerraNode Class Reference

This class implements a generic node in the ArchesTree model. More...

#include <archestree.h>

Inheritance diagram for TerraNode:

Public Member Functions
	TerraNode (const Box2 &=Box2::Infinity)
	Create a node. More...
virtual Box2	GetBox () const
	Returns the bouding box of a node.
virtual ScalarAlpha	ElevationAlpha (const Vector2 &) const
	Compute the elevation and weight. More...
virtual double	Elevation (const Vector2 &) const
	Compute the elevation at a given position. More...
virtual double	Alpha (const Vector2 &) const
	Compute the alpha mask at a given position. More...
virtual Vector2	Gradient (const Vector2 &) const
	Compute the gradient at a given position. More...
virtual Vector	Normal (const Vector2 &) const
	Compute the normal at a given position. More...
virtual void	writeJson (QJsonObject &)
	Compute the Json Document of the subtree.
virtual int	Traversal (const Vector2 &) const
	Compute the number of nodes that are traversed when evaluating the tree. More...
virtual int	Memory () const
	Compute the size of a node.
ScalarField2	Sample (const Array2 &) const
	Create a discrete scalar field by sampling the elevation over a given domain. More...
ScalarField2	Alpha (const Array2 &) const
	Create a discrete scalar field by sampling the elevation over a given domain. More...
void	Blend (HeightField &) const
	Blend a given node with an existing terrain over an input heightfield. More...
void	Add (HeightField &) const
	Add a given node with an existing heightfield. More...
virtual void	Draw (QGraphicsScene &) const
	Renders the node into a QGraphicsScene. More...

Protected Attributes
Box2	box = Box2::Infinity
	Bounding box.

Static Protected Attributes
static const double	epsilon = 1e-2
	Epsilon value for gradient computations.

Detailed Description

This class implements a generic node in the ArchesTree model.

The default elevation function is set to 0 and the weight to 1.

Constructor & Destructor Documentation

TerraNode()

TerraNode::TerraNode ( const Box2 &  box = Box2::Infinity )

explicit

Create a node.

Parameters

box

The box.

Referenced by Memory().

Member Function Documentation

Add()

void TerraNode::Add

(

HeightField &

h

)

const

Add a given node with an existing heightfield.

Parameters

h	HeighfField.

References ScalarAlpha::Alpha(), box, ElevationAlpha(), and ScalarAlpha::Value().

Alpha() [1/2]

ScalarField2 TerraNode::Alpha

(

const Array2 &

a

)

const

Create a discrete scalar field by sampling the elevation over a given domain.

Parameters

a

Domain.

References Alpha(), Array2::ArrayVertex(), Array2::GetSizeX(), and Array2::GetSizeY().

Alpha() [2/2]

double TerraNode::Alpha ( const Vector2 &  p ) const

virtual

Compute the alpha mask at a given position.

See also

Elevation

Parameters

p

Point.

References ScalarAlpha::Alpha(), and ElevationAlpha().

Referenced by Alpha().

Blend()

void TerraNode::Blend

(

HeightField &

h

)

const

Blend a given node with an existing terrain over an input heightfield.

Let a the mask of the node, the mask of the heightfield is implicitly defined as (1-a).

Parameters

h	HeighfField.

References ScalarAlpha::Alpha(), box, ElevationAlpha(), Math::Lerp(), and ScalarAlpha::Value().

Draw()

void TerraNode::Draw ( QGraphicsScene &  scene ) const

virtual

Renders the node into a QGraphicsScene.

Draws the box.

Parameters

scene

The scene.

Reimplemented in TerraBinary, TerraBlend, TerraPlateau, TerraVertex, TerraDisc, TerraCurveThick, TerraAddMusgrave, and TerraOcean.

References box, and Box2::Draw().

Referenced by TerraBinary::Draw(), and TerraAddMusgrave::Draw().

Elevation()

double TerraNode::Elevation ( const Vector2 &  p ) const

virtual

Compute the elevation at a given position.

This is a shortcut for:

TerraNode* node; // Node
double e=node->ElevationAlpha(p).Value(); // Get elevation from ScalarAlpha

Parameters

p

Point.

References ElevationAlpha(), and ScalarAlpha::Value().

Referenced by Gradient(), ArchesTree::Intersect(), and Sample().

ElevationAlpha()

ScalarAlpha TerraNode::ElevationAlpha ( const Vector2 &  ) const

virtual

Compute the elevation and weight.

Parameters

p

Point.

Reimplemented in TerraRotate, TerraTransform, TerraDunes, TerraGrid, TerraBlend, TerraBlendGrid, TerraUnion, TerraLowest, TerraAdd, TerraSub, TerraReplace, TerraBinaryBlend, Terra2015Replace, TerraPlateau, TerraVertex, TerraDisc, TerraVertexSlope, Terra2013VertexSlopeNoise, TerraVertexNoise, TerraDiscNoise, TerraVertexNoiseRydge, TerraVertexFractal, TerraBox, TerraBoxImage, TerraVertexImage, TerraQuadrangleImage, TerraCubic, TerraCrater, TerraCubicImage, TerraScale, TerraDiscCut, TerraClampWeight, TerraTranslate, TerraWarpNoise, TerraTwist, TerraCircleWarp, Terra2015ReplaceAlpha, Terra2015ReplaceMaxAlpha, TerraSmooth, TerraCurveThick, TerraAddMusgrave, TerraOcean, TerraUnary, TerraOperator, and TerraImages.

Referenced by Add(), Alpha(), Blend(), ArchesTree::CreateLayerStack(), ArchesTree::dichotomie(), Elevation(), TerraRotate::ElevationAlpha(), TerraTransform::ElevationAlpha(), TerraGrid::ElevationAlpha(), TerraLowest::ElevationAlpha(), TerraAdd::ElevationAlpha(), TerraSub::ElevationAlpha(), TerraReplace::ElevationAlpha(), TerraBinaryBlend::ElevationAlpha(), Terra2015Replace::ElevationAlpha(), TerraPlateau::ElevationAlpha(), TerraScale::ElevationAlpha(), TerraDiscCut::ElevationAlpha(), TerraClampWeight::ElevationAlpha(), TerraTranslate::ElevationAlpha(), TerraWarpNoise::ElevationAlpha(), TerraTwist::ElevationAlpha(), TerraCircleWarp::ElevationAlpha(), Terra2015ReplaceAlpha::ElevationAlpha(), Terra2015ReplaceMaxAlpha::ElevationAlpha(), TerraSmooth::ElevationAlpha(), TerraAddMusgrave::ElevationAlpha(), ArchesTree::GetBedrock(), ArchesTree::GetFoam(), ArchesTree::GetSand(), ArchesTree::GetTriangles(), and ArchesTree::GetWater().

Gradient()

Vector2 TerraNode::Gradient ( const Vector2 &  p ) const

virtual

Compute the gradient at a given position.

Parameters

p

Point.

References Elevation(), and epsilon.

Referenced by Normal().

Normal()

Vector TerraNode::Normal ( const Vector2 &  p ) const

virtual

Compute the normal at a given position.

See also

TerraNode::Gradient

Parameters

p

Point.

References Gradient().

Referenced by ArchesTree::CreateMesh().

Sample()

ScalarField2 TerraNode::Sample

(

const Array2 &

a

)

const

Create a discrete scalar field by sampling the elevation over a given domain.

Parameters

a

Domain.

References Array2::ArrayVertex(), Elevation(), Array2::GetSizeX(), and Array2::GetSizeY().

Referenced by ArchesTree::HeightFieldRock(), ArchesTree::HeightFieldSand(), and ArchesTree::HeightFieldWater().

Traversal()

int TerraNode::Traversal ( const Vector2 &  p ) const

virtual

Compute the number of nodes that are traversed when evaluating the tree.

Parameters

p

Point.

Reimplemented in TerraBinary, TerraUnary, TerraPrimitive, TerraBlend, and TerraAddMusgrave.

Referenced by ArchesTree::Traversal(), TerraBinary::Traversal(), TerraUnary::Traversal(), and TerraAddMusgrave::Traversal().