Common mistakes
related to fixedTimeStepping - UNCOVERED
a.) Design-Time Planning and Recognition of Hardware Min. Sys. Requirements
b.) "Scaling the World" - Gravity, Mass, Size and Hidden Effects of fixedStepping
c.) Jitter, Wobbles, Choppiness and Slowdowns: Unstable Physics & Smooth Animation

Common pitfalls
for any kind of simulation, say - MOLECULAR DYNAMICS
-"Error and timing analysis
of multiple time-step integration methods for molecular dynamics"

-"In molecular dynamics simulations,
'Energy Drift' is the gradual change in the total energy of a closed system"

-"Multiple time-step integration
hampered by parametric resonance exhibits the instability phenomenon"

Allegory Novella, Tech. Paper
& Chronicles of an Algorithm discovery: Three bugs with one stone.. allegory continues

Sep 2, 2008
>"i'm just saying that undersampling does not quite work "correctly" ..at first i thought that was in agreement, but then it turned out to be a matter of interpretation ...the rest was to define "undersampling" in more practical terms, something like this.."

"Half-solution A"
//----------------------------------------------------------------------
accum= 0.0f;
STEP= 1.0f / 60;
fpsTensor= 30;

while( theBeatGoesOn )
{

}
//----------------------------------------------------------------------
(R) All rights reserved, dont you dare use this code unless you can prove to me you're human being.
Use of this algorithm in commercial products without my permission will be cheerfully taken to court.

+++"Half-solution A"
//----------------------------------------------------------------------
//-------------------------- *** 1st algo - scaling the TIME "inside"
static btClock realTime;
double simDT, anmDT, STEP;
double secCnt, deltaTime = 0.0;
int cnt, FPS, SPS, fpsTensor= 60;
int btDiscreteDynamicsWorld::stepSimulation(btScalar timeStep, int maxSubSteps, btScalar fixedTimeStep)
{
deltaTime= double(realTime.getTimeMicroseconds())*0.000001f;
if(deltaTime > 0.75) deltaTime= 0; STEP= fixedTimeStep;
m_localTime+= deltaTime; realTime.reset(); FPS++;
saveKinematicState(fixedTimeStep); applyGravity();
anmDT= deltaTime - simDT; if(cnt > 0) simDT/= cnt; cnt= 0;
while( m_localTime >= fixedTimeStep )
{
cnt++; SPS++; internalSingleStepSimulation(fixedTimeStep);
m_localTime-= (simDT >= STEP)? simDT+(STEP*anmDT*fpsTensor) : STEP;
}
synchronizeMotionStates(); clearForces();
simDT= double(realTime.getTimeMicroseconds())*0.000001f;
return cnt;
}

+++"Full-solution A" (simplistic accumulator)
//----------------------------------------------------------------------
//-------------------------- *** 2nd algo - capping the TIME "outside"
int btDiscreteDynamicsWorld::stepSimulation(
btScalar timeStep,int maxSubSteps, btScalar fixedTimeStep)
{
    m_localTime+= (timeStep < fixedTimeStep*2)? timeStep : fixedTimeStep*2;
    saveKinematicState(fixedTimeStep); applyGravity(); maxSubSteps= 0;
    while( m_localTime >= fixedTimeStep )
    {
       internalSingleStepSimulation(fixedTimeStep);
       m_localTime-= fixedTimeStep; maxSubSteps++;
    }
    synchronizeMotionStates(); clearForces();
return maxSubSteps;
}
//--------------------------------------------------------------------------------
//================================================================================
content="Microsoft FrontPage Express 2.0"

"The Hitchhiker's Guide to the Earth"

Prixoni & Mixoni
AROUND the WORLD in 80 YEARS..

Prixoni, living at the thin line between life and death has pressed this creature to adapt in the most amazing way. With the help of magic rituals it is able to transcend to lower levels of awareness where it can sustain prolonged period of time virtually dead. Ritual begins with meticulous preparation where bodily fluids are exerted through the front end of the creature's body that resembles human head. Then, it assumes the "death pose", and in this state all vital functions cease. Scientists are completely baffled as how it is possible for this creature to revive.

Mixoni, doesn't really exists, it is phantasmal manifestation that accompanies Prixoni in its thaumaturgical ventures as an odylic force to another spheres of existence. It possesses great power to ignore and awesome ability to misunderstand.

The Ultimate "Best of the World"