KeepUpAttitudeCorrection Class Reference

#include <src/KeepUpAttitudeCorrection.h>

Inheritance diagram for KeepUpAttitudeCorrection:

[legend]Collaboration diagram for KeepUpAttitudeCorrection:

[legend]List of all members.

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Detailed Description

When mapping old direction to the new one, the rotation around the new direction is made so the up vector lies in the plane of the target up vector.

Alternatively, a function is provided to force the up vector to match perfectly the target vector, which is not the same, as it modifies the forward vector.

No costly acos or sin are used, the quaternion is found only with fast geometrical properties. See for example http://logiciels.cnes.fr/MARMOTTES/marmottes-mathematique.pdf for an explanation of the math used.

Care is taken for reconditionning the quaternion after too many rotations, when this becomes necessary.

Author:

Nicolas Brodu

Public Member Functions
	KeepUpAttitudeCorrection (const osg::Vec3d &targetUpVector, const osg::Vec3d &initUp)
	In addition to the target up vector, the initial up vector must be provided.
virtual void	set (const osg::Vec3d &targetUpVector, const osg::Vec3d &initUp)
	Avoid building a new object when we can re-use an existing one.
const osg::Vec3d &	getUpVector () const
	read-only accessor => use matchTarget or set to change
virtual void	updateAttitude (osg::Quat &newAttitude, const osg::Quat &oldAttitude, const osg::Vec3d &newForward, const osg::Vec3d &oldForward)
	See class descrition.
virtual void	matchTarget (osg::Quat &newAttitude, osg::Vec3d &newForward)
	Force the up vector to match perfectly the target vector, and modify the forward direction accordingly.
Public Attributes
osg::Vec3d	targetUp
	The target Up vector.
Protected Attributes
osg::Quat	qpassage
osg::Vec3d	newUp
osg::Vec3d	oldUp

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Constructor & Destructor Documentation

KeepUpAttitudeCorrection::KeepUpAttitudeCorrection (  const osg::Vec3d &  targetUpVector, const osg::Vec3d &  initUp )

In addition to the target up vector, the initial up vector must be provided. The matchTarget function also needs a current Up vector.

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Member Function Documentation

void KeepUpAttitudeCorrection::matchTarget (  osg::Quat &  newAttitude, osg::Vec3d &  newForward )  [virtual]

Force the up vector to match perfectly the target vector, and modify the forward direction accordingly. The mapping from Up to targetUp is done using shortest-angle quaternion rotation.

void KeepUpAttitudeCorrection::set (  const osg::Vec3d &  targetUpVector, const osg::Vec3d &  initUp )  [virtual]

Avoid building a new object when we can re-use an existing one. Equivalent to operator= In addition to the target up vector, the initial up vector must be provided. The matchTarget function also needs a current Up vector.

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Member Data Documentation

osg::Vec3d KeepUpAttitudeCorrection::targetUp

The target Up vector. See the class description. See also: matchTarget

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

• KeepUpAttitudeCorrection.h
• KeepUpAttitudeCorrection.cpp

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