Module simpa.core

Package simpa.core.api.utils

Class LocalFramesCalculator

java.lang.Object

simpa.core.api.utils.LocalFramesCalculator

public class LocalFramesCalculator
extends Object

Calculator class to define local frames along a curve. It uses a parallel transport algorithm. An initial vector is parallel transported along a general 3D curve. It can optimize an initial vector if the OPTIMIZE_TORSION strategy is selected or uses the given one when the PARALLEL_TRANSPORT_WITHOUT_OPTIMIZATION strategy is selected. For the algorithm of the parallel transport See: Parallel Transport Approach to Curve Framing Andrew J. Hanson and Hui Ma https://legacy.cs.indiana.edu/ftp/techreports/TR425.pdf

Author:

lbojtar

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	LocalFramesCalculator.Strategy	The MINIMIZE_TORSION strategy is searching for an initial vector normal the the first tangent vector of the curve such the total torsion is minimized along the curve.

Field Summary

Fields

Modifier and Type	Field	Description
static final LocalFramesCalculator.Strategy	DEFAULT_STRATEGY
static final org.apache.commons.math3.geometry.euclidean.threed.Vector3D	DEFAULT_VERTICAL

Constructor Summary

Constructors

Constructor	Description
LocalFramesCalculator(List<org.apache.commons.math3.geometry.euclidean.threed.Vector3D> curve, boolean closed, LocalFramesCalculator.Strategy strategy, org.apache.commons.math3.geometry.euclidean.threed.Vector3D vertical)	Constructor for LocalFramesCalculator.

Method Summary

Modifier and Type	Method	Description
List<LocalFrame>	getLocalFrames()	Get the local frame calculated.
void	writeToFile(String file, int increment)	Writes the reference frame unit vectors into a file

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_STRATEGY

public static final LocalFramesCalculator.Strategy DEFAULT_STRATEGY

DEFAULT_VERTICAL

public static final org.apache.commons.math3.geometry.euclidean.threed.Vector3D DEFAULT_VERTICAL

Constructor Details

LocalFramesCalculator

public LocalFramesCalculator(List<org.apache.commons.math3.geometry.euclidean.threed.Vector3D> curve,
 boolean closed,
 LocalFramesCalculator.Strategy strategy,
 org.apache.commons.math3.geometry.euclidean.threed.Vector3D vertical)

Constructor for LocalFramesCalculator.

Parameters:

curve - A curve in 3D.

closed - Closed or open indicator. If closed the last point in the list considered connected to the first one.

strategy - Strategy to optimize the initial vector. It determines how the local frame is constructed.

vertical - Preferred vertical direction. It can be null, in this case by default it is the +Y global axis. There are two optimal initial orientation which minimizes the torsion of a planar curve. By setting this vector one can be chosen. The preferred vertical direction should be perpendicular to the first tangent vector of the curve.

Method Details

writeToFile

public void writeToFile(String file,
 int increment)

Writes the reference frame unit vectors into a file

Parameters:

file - Output file.

increment - Increment of steps while sampling the curve. The value 1 takes all the curve points, 2 every second, 3 every third and so on.

getLocalFrames

public List<LocalFrame> getLocalFrames()

Get the local frame calculated. The calculation itself called by the constructor.

Returns:

List of local frame objects. There is a frame in the list for each curve points given at the constructor.