Ogre::TransformBase Class Reference

Class encapsulating a standard 4x4 homogeneous matrix. More...

#include <OgreMatrix4.h>

Inheritance diagram for Ogre::TransformBase:

Public Member Functions
Real	determinant () const
void	extract3x3Matrix (Matrix3 &m3x3) const
Quaternion	extractQuaternion () const
Vector3	getTrans () const
	Extracts the translation transformation part of the matrix. More...
Matrix3	linear () const
	Extracts the rotation / scaling part of the Matrix as a 3x3 matrix. More...
void	makeInverseTransform (const Vector3 &position, const Vector3 &scale, const Quaternion &orientation)
	Building an inverse Affine3 from orientation / scale / position. More...
void	makeTrans (const Vector3 &v)
	Builds a translation matrix. More...
void	makeTrans (Real tx, Real ty, Real tz)
void	makeTransform (const Vector3 &position, const Vector3 &scale, const Quaternion &orientation)
	Building a Affine3 from orientation / scale / position. More...
Real *	operator[] (size_t iRow)
const Real *	operator[] (size_t iRow) const
void	set3x3Matrix (const Matrix3 &mat3)
	Assignment from 3x3 matrix. More...
void	setScale (const Vector3 &v)
	Sets the scale part of the matrix. More...
void	setTrans (const Vector3 &v)
	Sets the translation transformation part of the matrix. More...
Matrix4	transpose () const

Friends
std::ostream &	operator<< (std::ostream &o, const TransformBase &mat)
	Function for writing to a stream. More...

Detailed Description

Class encapsulating a standard 4x4 homogeneous matrix.

Remarks

OGRE uses column vectors when applying matrix multiplications, This means a vector is represented as a single column, 4-row matrix. This has the effect that the transformations implemented by the matrices happens right-to-left e.g. if vector V is to be transformed by M1 then M2 then M3, the calculation would be M3 * M2 * M1 * V. The order that matrices are concatenated is vital since matrix multiplication is not commutative, i.e. you can get a different result if you concatenate in the wrong order.

The use of column vectors and right-to-left ordering is the standard in most mathematical texts, and is the same as used in OpenGL. It is, however, the opposite of Direct3D, which has inexplicably chosen to differ from the accepted standard and uses row vectors and left-to-right matrix multiplication.

OGRE deals with the differences between D3D and OpenGL etc. internally when operating through different render systems. OGRE users only need to conform to standard maths conventions, i.e. right-to-left matrix multiplication, (OGRE transposes matrices it passes to D3D to compensate).

The generic form M * V which shows the layout of the matrix entries is shown below:

        [ m[0][0]  m[0][1]  m[0][2]  m[0][3] ]   {x}
        | m[1][0]  m[1][1]  m[1][2]  m[1][3] | * {y}
        | m[2][0]  m[2][1]  m[2][2]  m[2][3] |   {z}
        [ m[3][0]  m[3][1]  m[3][2]  m[3][3] ]   {1}
    

Member Function Documentation

operator[]() [1/2]

Real* Ogre::TransformBase::operator[] ( size_t  iRow )

inline

operator[]() [2/2]

const Real* Ogre::TransformBase::operator[] ( size_t  iRow ) const

inline

set3x3Matrix()

void Ogre::TransformBase::set3x3Matrix ( const Matrix3 &  mat3 )

inline

Assignment from 3x3 matrix.

linear()

Matrix3 Ogre::TransformBase::linear ( ) const

inline

Extracts the rotation / scaling part of the Matrix as a 3x3 matrix.

extract3x3Matrix()

void Ogre::TransformBase::extract3x3Matrix ( Matrix3 &  m3x3 ) const

inline

extractQuaternion()

Quaternion Ogre::TransformBase::extractQuaternion ( ) const

inline

setTrans()

void Ogre::TransformBase::setTrans ( const Vector3 &  v )

inline

Sets the translation transformation part of the matrix.

getTrans()

Vector3 Ogre::TransformBase::getTrans ( ) const

inline

Extracts the translation transformation part of the matrix.

Referenced by Ogre::Affine3::operator const Matrix4 &().

setScale()

void Ogre::TransformBase::setScale ( const Vector3 &  v )

inline

Sets the scale part of the matrix.

makeTrans() [1/2]

void Ogre::TransformBase::makeTrans ( const Vector3 &  v )

inline

Builds a translation matrix.

makeTrans() [2/2]

void Ogre::TransformBase::makeTrans ( Real  tx, Real  ty, Real  tz  )

inline

determinant()

Real Ogre::TransformBase::determinant

(

)

const

makeTransform()

void Ogre::TransformBase::makeTransform	(	const Vector3 &	position,
		const Vector3 &	scale,
		const Quaternion &	orientation
	)

Building a Affine3 from orientation / scale / position.

Remarks

Transform is performed in the order scale, rotate, translation, i.e. translation is independent of orientation axes, scale does not affect size of translation, rotation and scaling are always centered on the origin.

makeInverseTransform()

void Ogre::TransformBase::makeInverseTransform	(	const Vector3 &	position,
		const Vector3 &	scale,
		const Quaternion &	orientation
	)

Building an inverse Affine3 from orientation / scale / position.

Remarks

As makeTransform except it build the inverse given the same data as makeTransform, so performing -translation, -rotate, 1/scale in that order.

Friends And Related Function Documentation

operator<<

std::ostream& operator<< ( std::ostream &  o, const TransformBase &  mat  )

friend

Function for writing to a stream.

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

• OgreMatrix4.h