chrono::ChFrame< Real > Class Template Reference

Description

template<class Real = double>
class chrono::ChFrame< Real >

Representation of a 3D transform.

A 'frame' coordinate system has a translation and a rotation respect to a 'parent' coordinate system, usually the absolute (world) coordinates. Differently from a simple ChCoordsys object, the ChFrame also stores the 3x3 rotation matrix implements, which permits some optimizations, especially when a large number of vectors must be transformed by the same frame.

See Coordinate Systems manual page.

#include <ChFrame.h>

Inheritance diagram for chrono::ChFrame< Real >:

Public Member Functions

 ChFrame ()
 Default constructor (identity frame).
 
 ChFrame (const ChVector3< Real > &v, const ChQuaternion< Real > &q=ChQuaternion< Real >(1, 0, 0, 0))
 Construct from position and rotation (as quaternion).
 
 ChFrame (const ChVector3< Real > &v, const ChMatrix33< Real > &R)
 Construct from pos and rotation (as a 3x3 matrix).
 
 ChFrame (const ChVector3< Real > &v, const Real angle, const ChVector3< Real > &u)
 Construct from position mv and rotation of angle alpha around unit vector mu.
 
 ChFrame (const ChCoordsys< Real > &C)
 Construct from a coordsys.
 
 ChFrame (const ChFrame< Real > &other)
 Copy constructor, build from another frame.
 
ChFrame< Real > & operator= (const ChFrame< Real > &other)
 Assignment operator: copy from another frame.
 
bool operator== (const ChFrame< Real > &other) const
 Returns true for identical frames.
 
bool operator!= (const ChFrame< Real > &other) const
 Returns true for different frames.
 
ChFrame< Real > operator* (const ChFrame< Real > &F) const
 Transform another frame through this frame. More...
 
ChFrame< Real > operator>> (const ChFrame< Real > &F) const
 Transform another frame through this frame. More...
 
ChVector3< Real > operator* (const ChVector3< Real > &v) const
 Transform a vector through this frame (express in parent frame). More...
 
ChVector3< Real > operator/ (const ChVector3< Real > &v) const
 Transform a vector through this frame (express from parent frame). More...
 
ChFrame< Real > & operator>>= (const ChFrame< Real > &F)
 Transform this frame by pre-multiplication with another frame. More...
 
ChFrame< Real > & operator*= (const ChFrame< Real > &F)
 Transform this frame by post-multiplication with another frame. More...
 
ChFrame< Real > & operator>>= (const ChVector3< Real > &v)
 Transform this frame by pre-multiplication with a given vector (translate frame).
 
ChFrame< Real > & operator>>= (const ChQuaternion< Real > &q)
 Transform this frame by pre-multiplication with a given quaternion (rotate frame).
 
ChFrame< Real > & operator>>= (const ChCoordsys< Real > &C)
 Transform this frame by pre-multiplication with a given coordinate system.
 
const ChCoordsys< Real > & GetCoordsys () const
 Return both current rotation and translation as a ChCoordsys object.
 
const ChVector3< Real > & GetPos () const
 Return the current translation vector.
 
const ChQuaternion< Real > & GetRot () const
 Return the current rotation quaternion.
 
const ChMatrix33< Real > & GetRotMat () const
 Return the current 3x3 rotation matrix.
 
ChVector3< Real > GetRotAxis () const
 Get axis of finite rotation, in parent space.
 
Real GetRotAngle () const
 Get angle of rotation about axis of finite rotation.
 
void SetCoordsys (const ChCoordsys< Real > &C)
 Impose both translation and rotation as a single ChCoordsys. More...
 
void SetCoordsys (const ChVector3< Real > &v, const ChQuaternion< Real > &q)
 Impose both translation and rotation. More...
 
void SetRot (const ChQuaternion< Real > &q)
 Impose the rotation as a quaternion. More...
 
void SetRot (const ChMatrix33< Real > &R)
 Impose the rotation as a 3x3 matrix. More...
 
void SetPos (const ChVector3< Real > &pos)
 Impose the translation vector.
 
void ConcatenatePreTransformation (const ChFrame< Real > &F)
 Apply a transformation (rotation and translation) represented by another frame. More...
 
void ConcatenatePostTransformation (const ChFrame< Real > &F)
 Apply a transformation (rotation and translation) represented by another frame F in local coordinate. More...
 
void Move (const ChVector3< Real > &v)
 An easy way to move the frame by the amount specified by vector v, (assuming v expressed in parent coordinates)
 
void Move (const ChCoordsys< Real > &C)
 Apply both translation and rotation, assuming both expressed in parent coordinates, as a vector for translation and quaternion for rotation,.
 
ChVector3< Real > TransformPointLocalToParent (const ChVector3< Real > &v) const
 Transform a point from the local frame coordinate system to the parent coordinate system.
 
ChVector3< Real > TransformPointParentToLocal (const ChVector3< Real > &v) const
 Transforms a point from the parent coordinate system to local frame coordinate system.
 
ChVector3< Real > TransformDirectionLocalToParent (const ChVector3< Real > &d) const
 Transform a direction from the parent frame coordinate system to 'this' local coordinate system.
 
ChVector3< Real > TransformDirectionParentToLocal (const ChVector3< Real > &d) const
 Transforms a direction from 'this' local coordinate system to parent frame coordinate system.
 
ChWrench< Real > TransformWrenchLocalToParent (const ChWrench< Real > &w) const
 Transform a wrench from the local coordinate system to the parent coordinate system.
 
ChWrench< Real > TransformWrenchParentToLocal (const ChWrench< Real > &w) const
 Transform a wrench from the parent coordinate system to the local coordinate system.
 
ChFrame< Real > TransformLocalToParent (const ChFrame< Real > &F) const
 Transform a frame from 'this' local coordinate system to parent frame coordinate system.
 
ChFrame< Real > TransformParentToLocal (const ChFrame< Real > &F) const
 Transform a frame from the parent coordinate system to 'this' local frame coordinate system.
 
bool Equals (const ChFrame< Real > &other) const
 Returns true if this transform is identical to the other transform.
 
bool Equals (const ChFrame< Real > &other, Real tol) const
 Returns true if this transform is equal to the other transform, within a tolerance 'tol'.
 
void Normalize ()
 Normalize the rotation, so that quaternion has unit length.
 
virtual void SetIdentity ()
 Sets to no translation and no rotation.
 
virtual void Invert ()
 Invert in place. More...
 
ChFrame< Real > GetInverse () const
 Return the inverse transform.
 
virtual void ArchiveOut (ChArchiveOut &archive)
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive)
 Method to allow de-serialization of transient data from archives.
 

Protected Attributes

ChCoordsys< Real > m_csys
 position and rotation, as vector + quaternion
 
ChMatrix33< Real > m_rmat
 3x3 orthogonal rotation matrix
 

Friends

class FmuChronoComponentBase
 

Member Function Documentation

◆ ConcatenatePostTransformation()

template<class Real = double>
void chrono::ChFrame< Real >::ConcatenatePostTransformation ( const ChFrame< Real > &  F)
inline

Apply a transformation (rotation and translation) represented by another frame F in local coordinate.

This is equivalent to post-multiply this frame by the other frame F: this'= this * F or this'= F >> this

◆ ConcatenatePreTransformation()

template<class Real = double>
void chrono::ChFrame< Real >::ConcatenatePreTransformation ( const ChFrame< Real > &  F)
inline

Apply a transformation (rotation and translation) represented by another frame.

This is equivalent to pre-multiply this frame by the other frame F: this'= F * this or this' = this >> F

◆ Invert()

template<class Real = double>
virtual void chrono::ChFrame< Real >::Invert ( )
inlinevirtual

Invert in place.

If w = A * v, after A.Invert() we have v = A * w;

Reimplemented in chrono::ChFrameMoving< Real >, and chrono::ChFrameMoving< double >.

◆ operator*() [1/2]

template<class Real = double>
ChFrame<Real> chrono::ChFrame< Real >::operator* ( const ChFrame< Real > &  F) const
inline

Transform another frame through this frame.

If A is this frame and F another frame expressed in A, then G = A * F is the frame F expresssed in the parent frame of A. For a sequence of transformations, i.e. a chain of coordinate systems, one can also write: G = F_1to0 * F_2to1 * F_3to2 * F; i.e., just like done with a sequence of Denavitt-Hartemberg matrix multiplications. This operation is not commutative.

◆ operator*() [2/2]

template<class Real = double>
ChVector3<Real> chrono::ChFrame< Real >::operator* ( const ChVector3< Real > &  v) const
inline

Transform a vector through this frame (express in parent frame).

If A is this frame and v a vector expressed in this frame, w = A * v is the vector expressed in the parent frame of A. For a sequence of transformations, i.e. a chain of coordinate systems, one can also write: w = F_1to0 * F_2to1 * F_3to2 * v; i.e., just like done with a sequence of Denavitt-Hartemberg matrix multiplications. This operation is not commutative. NOTE: since c++ operator execution is from left to right, in case of multiple transformations w = v >> C >> B >> A may be faster than w = A * B * C * v

◆ operator*=()

template<class Real = double>
ChFrame<Real>& chrono::ChFrame< Real >::operator*= ( const ChFrame< Real > &  F)
inline

Transform this frame by post-multiplication with another frame.

If A is this frame, then A *= F means A' = A * F or A' = F >> A.

◆ operator/()

template<class Real = double>
ChVector3<Real> chrono::ChFrame< Real >::operator/ ( const ChVector3< Real > &  v) const
inline

Transform a vector through this frame (express from parent frame).

If A is this frame and v a vector expressed in the parent frame of A, then w = A / v is the vector expressed in A. In other words, w = A * v implies v = A/w.

◆ operator>>()

template<class Real = double>
ChFrame<Real> chrono::ChFrame< Real >::operator>> ( const ChFrame< Real > &  F) const
inline

Transform another frame through this frame.

If A is this frame and F another frame expressed in A, then G = F >> A is the frame F expresssed in the parent frame of A. For a sequence of transformations, i.e. a chain of coordinate systems, one can also write: G = F >> F_3to2 >> F_2to1 >> F_1to0; i.e., just like done with a sequence of Denavitt-Hartemberg matrix multiplications (but reverting order). This operation is not commutative.

◆ operator>>=()

template<class Real = double>
ChFrame<Real>& chrono::ChFrame< Real >::operator>>= ( const ChFrame< Real > &  F)
inline

Transform this frame by pre-multiplication with another frame.

If A is this frame, then A >>= F means A' = F * A or A' = A >> F.

◆ SetCoordsys() [1/2]

template<class Real = double>
void chrono::ChFrame< Real >::SetCoordsys ( const ChCoordsys< Real > &  C)
inline

Impose both translation and rotation as a single ChCoordsys.

Note: the quaternion part must be already normalized.

◆ SetCoordsys() [2/2]

template<class Real = double>
void chrono::ChFrame< Real >::SetCoordsys ( const ChVector3< Real > &  v,
const ChQuaternion< Real > &  q 
)
inline

Impose both translation and rotation.

Note: the quaternion part must be already normalized.

◆ SetRot() [1/2]

template<class Real = double>
void chrono::ChFrame< Real >::SetRot ( const ChMatrix33< Real > &  R)
inline

Impose the rotation as a 3x3 matrix.

Note: the rotation matrix must be already orthogonal.

◆ SetRot() [2/2]

template<class Real = double>
void chrono::ChFrame< Real >::SetRot ( const ChQuaternion< Real > &  q)
inline

Impose the rotation as a quaternion.

Note: the quaternion must be already normalized.


The documentation for this class was generated from the following file:
  • /builds/uwsbel/chrono/src/chrono/core/ChFrame.h