That tells me that the skewers of the inertia matrix if critical to get the effect,
you can see that professor Walter Lewin Lewin points that out, if a shape with a very skew inertia matrix the effect does not happens, I disagree, I believe the effect should happen for all shape, is just that the space is why chis happen is outside of the practical limit physical constraints of nature.
for example I was trying to simulate a earth precession, and it seem as if not matter what I did in did not worked, the I let the simulation running for hours and when to watch TV, and when I cam back the annual velocity and almost at 80 degree,
so I check out the code. and what happen is that the prevision rate is a function of the difference for the skew inertia (Imax - Imin) / Imax
so the period of that rotation is very, very large value. this is because for a sphere all axis are axis of symmetry no wonder the earth precession is 26 thousand years.
of could I could fake the value and made I min a long small, so that (Imax - Imin) / Imax grows larger, but that will be cheating, then I realice that we do parcticla example have example of this, is called the Frisbee effect
https://www.youtube.com/watch?v=DLdyR6ZMIwk
basically by making Imin smaller is the equivalent of make a thin cylinder, so I made the demo with a thin cylinder and it works by the book, processing at twice he main omega.
here is the interesting part if Imin == IMax the precession will be zero. and the will be a spherical shape. so the object wil rtale liek si was preseccing and will conserve angular velocity and angular momentum because that the case where Ixx = Tyy == Tzz
this is not wrong but is not right either because is a special case.
This is hwo Mr Kenny Bodin and his student de managed to unilaterally discredit me and may work, base of a total fallacy of an argument fro autoritity.
http://www8.cs.umu.se/education/examina ... gRolin.pdf
if you open the link and go to page 38. you will see the graph of angular momentum total energy.
there is so much wrong with that methodology that is breathtaken. I will just address the Giro part
The general equation of motion is this
I * a = T - w x (I * w)
but T = 0 so the equation is
I * a = - w x (I * w)
and the energy will be
E = w.Dot ((I * w))
as you can see of the three engine they tested, ODE was the one that was trying to do the right thing,
basically ODE was integation this
I * a = - w x L
but since ODE uses an explicit integration, that blew up and
E = w.Dot ((I * w)) went up out of control
Netwon was ignored Gyro velocity torques
I * a = 0
and
I * a = - w x (I * w)
which is the sine wave you see in the graph
because in newton the torque was a responsibility of the callback, but the did not do it and when called on it, they simply ignored me.
https://pybullet.org/Bullet/phpBB3/view ... f=4&t=1334
Instead to cut all my post and placed them out for contactex in one thread.
Had they add the torque function I posted, the energy would be conserved but not the angular momentum, and it would behave more like ODE but without explosion of energy because the position corrector integrator in newton took care of that.
what Novodex was doing was a total cheat the did this
Ix = Tx = Tz
therefore w x (w * L) == w x (w * Ixx) = 0
so they integrated
I * a = 0
and the energy was
E = w x (w * Ixx) = Ixx * w^2 = const.
you would think a self appointed expert like Kr Kenney Boddin would see thought that, instead he accepted those result an published it. This is what they concluded.
As shown by the results this test is hard for ODE and Newton. When running the simulation a little longer, the Newton toolkit will make the object stop moving. The simulation with ODE will explode. The documentation for ODE(section 12.12) explains this problem and gives some suggestions on how to make a simulation more stable. The suggestions are not used in this test since then the physical aspects wont be fair to the other engines. Novodex handles this test best, but still does not conserve angular momentum.
That was how they beat Newton based on a fallacious lies, and to this day that document has been used as a weapon in google scholar to discourage people in academia from even considering using the newton engine.