rt::element Class Reference

Geometric surface element unit. More...

#include <element.hpp>

Public Member Functions
	element ()
	Default constructor. More...
	element (const Geometry *g, const vector &position, const vector &normal, const vector &tangent)
	Contruct a surface element from its attributes. More...
	element (const element &)
	Copy constructor.
	~element ()
	Destructor.
vector	uv () const
	Get uv mapping of the element. More...
const vector &	position () const
	Position of the element on the surface. More...
const vector &	normal () const
	Normal of the element on the surface. More...
const vector &	tangent () const
	A tangent of the surface at this position. More...
vector	binormal () const
	A binormal of the surface at this point. More...
const Geometry *	geometry () const
	The geometry owner. More...
const Material *	material () const
	The surface material. More...
void	setMaterial (Material *m)
	Attach a material to the element. More...
const vector &	globalPosition () const
	Global position of the surface element. More...
const vector &	globalNormal () const
	Global normal of the surface element. More...
const vector &	globalTangent () const
	Global tangent of the surface element. More...
vector	globalBinormal () const
	Global binormal of the surface element. More...
element &	operator= (const element &)
	operator = More...

Detailed Description

Geometric surface element unit.

This class represents a unit of surface of a geometric element. It is described by its Geometry owner, the unit position, normal and tangent in the local geometry space.

Global position, normal and tangent can be retreived, but with some inexorable time consumtion. For this reason, global attributes will be computed only when its needed, and only one time.

A surface element can be attached to a Material. By default, the material is set to null.

There is some work to do around this class to avoid useless calculations of global components. Maybe construct an element directly from its global coordinates ? But local coordinantes will be needed to compute texture mapping...

Constructor & Destructor Documentation

element() [1/2]

rt::element::element

(

)

Default constructor.

Make a new null surface element.

element() [2/2]

rt::element::element	(	const Geometry *	g,
		const vector &	position,
		const vector &	normal,
		const vector &	tangent
	)

Contruct a surface element from its attributes.

Parameters

g	the Geometry owner
position	Location vector of the surface on the geometry
normal	Normal vector of the surface at this position
tangent	A tangent to the surface at this position

The element is build with material attribute set to null.

Member Function Documentation

binormal()

vector rt::element::binormal ( ) const

inline

A binormal of the surface at this point.

Returns

The cross product between the normal and a tangent.

geometry()

const Geometry* rt::element::geometry ( ) const

inline

The geometry owner.

Returns

A pointer to the Geometry this element belong to. Can be null.

globalBinormal()

vector rt::element::globalBinormal ( ) const

inline

Global binormal of the surface element.

Returns

The cross product between the global normal and a global tangent.

globalNormal()

const vector & rt::element::globalNormal

(

)

const

Global normal of the surface element.

Returns

The normal vector of the surface in global space referential.

This vector is computed only the first time this method is called.

globalPosition()

const vector & rt::element::globalPosition

(

)

const

Global position of the surface element.

Returns

The location vector in global space referential

This vector is computed only the first time this method is called.

globalTangent()

const vector & rt::element::globalTangent

(

)

const

Global tangent of the surface element.

Returns

A tangent vector mapped in global space referential.

This vector is computed only the first time this method is called.

material()

const Material* rt::element::material ( ) const

inline

The surface material.

By default, the material is set to null.

Returns

A pointer to the material attached to this element. Typicaly, it correspond to the material of the surface at this point. Can be null.

normal()

const vector& rt::element::normal ( ) const

inline

Normal of the element on the surface.

Returns

A normal vector in Geometry owner local space

operator=()

element & rt::element::operator=

(

const element &

e

)

operator =

Returns

This element after modification.

position()

const vector& rt::element::position ( ) const

inline

Position of the element on the surface.

Returns

A location vector in Geometry owner local space

setMaterial()

void rt::element::setMaterial ( Material *  m )

inline

Attach a material to the element.

Parameters

m	A pointer to the material to attach to.

Conventionally, and for the ray-tracer purpose, this material matchs the surface material at this location. This method is used by Object::hit in this very way.

tangent()

const vector& rt::element::tangent ( ) const

inline

A tangent of the surface at this position.

Returns

A tangent vector in Geometry owner local space

uv()

vector rt::element::uv

(

)

const

Get uv mapping of the element.

This function directly call Geometry::uv. Make sure that this is not a null surface element in order to call this function to avoid segmentation fault.

Returns

The UV texture coordinate of the surface at this point

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The documentation for this class was generated from the following files:

• sources/geometry/element.hpp
• sources/geometry/element.cpp