net.java.dev.joode.stepper
Class QuickStepper

java.lang.Object
  net.java.dev.joode.stepper.AbstractStepperFunction
      net.java.dev.joode.stepper.QuickStepper

All Implemented Interfaces:

StepperFunction

public class QuickStepper
extends AbstractStepperFunction

Field Summary

static QuickStepper	INSTANCE
QuickStepParameters	qsp
static boolean	RANDOMLY_REORDER_CONSTRAINTS for the SOR method: uncomment the following line to randomly reorder constraint rows during the solution.
static boolean	REORDER_CONSTRAINTS for the SOR method: uncomment the following line to determine a new constraint-solving order for each iteration.
static java.util.Random	rnd
static boolean	WARM_STARTING for the SOR and CG methods: uncomment the following line to use warm starting.

Fields inherited from class net.java.dev.joode.stepper.AbstractStepperFunction

GYROSCOPIC

Fields inherited from interface net.java.dev.joode.stepper.StepperFunction

EULER, RK4

Constructor Summary

QuickStepper()

Method Summary

void	SOR_LCP(int m, Matrix J, int[][] jb, Body[] body, Matrix3[] invI, float[] lambda, float[][] fc, float[] b, float[] lo, float[] hi, float[] cfm, int[] findex) SOR-LCP method note: fc is returned as inv(M)*J'*lambda, the constraint force is actually J'*lambda
void	stepConstraints(int m, World world, Body[] body, int bcount, Joint[] joint, int jcount, Joint.Info1[] info, int[] ofs, Matrix3[] invI, float stepsize)

Methods inherited from class net.java.dev.joode.stepper.AbstractStepperFunction

addExternalForces, createRowOffsetArray, getInverseInertiaTensors, getJointInfo, resetForces, step, tagBodies, updateVelocity

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final QuickStepper INSTANCE

WARM_STARTING

public static final boolean WARM_STARTING

for the SOR and CG methods: uncomment the following line to use warm starting. this definitely help for motor-driven joints. unfortunately it appears to hurt with high-friction contacts using the SOR method. use with care

See Also:

Constant Field Values

REORDER_CONSTRAINTS

public static final boolean REORDER_CONSTRAINTS

for the SOR method: uncomment the following line to determine a new constraint-solving order for each iteration. however, the qsort per iteration is expensive, and the optimal order is somewhat problem dependent.

See Also:

Constant Field Values

RANDOMLY_REORDER_CONSTRAINTS

public static final boolean RANDOMLY_REORDER_CONSTRAINTS

for the SOR method: uncomment the following line to randomly reorder constraint rows during the solution. depending on the situation, this can help a lot or hardly at all, but it doesn't seem to hurt.

See Also:

Constant Field Values

rnd

public static final java.util.Random rnd

qsp

public final QuickStepParameters qsp

Constructor Detail

QuickStepper

public QuickStepper()

Method Detail

stepConstraints

public void stepConstraints(int m,
                            World world,
                            Body[] body,
                            int bcount,
                            Joint[] joint,
                            int jcount,
                            Joint.Info1[] info,
                            int[] ofs,
                            Matrix3[] invI,
                            float stepsize)

Specified by:

stepConstraints in class AbstractStepperFunction

SOR_LCP

public void SOR_LCP(int m,
                    Matrix J,
                    int[][] jb,
                    Body[] body,
                    Matrix3[] invI,
                    float[] lambda,
                    float[][] fc,
                    float[] b,
                    float[] lo,
                    float[] hi,
                    float[] cfm,
                    int[] findex)

SOR-LCP method note: fc is returned as inv(M)*J'*lambda, the constraint force is actually J'*lambda

Parameters:

m - number of constraints

J - an m*12 matrix of constraint rows

jb - an array of first and second body numbers for each constraint row

invI - the global frame inverse inertia for each body (stacked 3x3 matrices)

lambda - return values

fc - returns the constraint force

b -

lo -

hi -