[ODE] Newbie Question on Numerical Integration Method

Piotr Obrzut piotr_obrzut at o2.pl
Wed Jun 8 14:03:19 MST 2005

Hi Alen,

7 czerwca 2005 (10:37:24) Alen wrote:

AL> Hi Piotr,

AL> Joint feedback forces are wrong because position correction in constraints
AL> is mixed with velocity correction, giveing you larger forces. You might want
AL> to look into some recently mentioned modifications (see threads "Patch for
AL> eliminating penetration bounce mega-force?" and "patch - position-correcting
AL> constraints", though you might need to dig some more backwards in time).
AL> Note that I didn't actually try this myself, so perhaps I cannot be sure
AL> that it is _the_ complete solution, as there might be some other reasons for
AL> wrong forces that pop up later, but this should at least help to get more
AL> correct forces, regardless of the solver used.

Thanks I was trying position-constraint path and it helped a bit
(feedback forces was more stable), but as you said this didn't
resolved all my problems, perhaps I will have to look closer on
quickstep solver and solver in general, but this will mean a lot
of doc reading so I will just drop this for now.

Oh and while testing I've found that on the begining of simulation my
model is getting crazy for vey little time and it is the main reason
of very large joint forces :) (but unfortunatly not the only reason).

btw. here is what I was(am) doing (nothing much but I had very little
time for this, maybe I will find some on my summer holidays):


   just run the mordobij.bat

   - for roatation camera use mouse + right button

   - for moving use arrows

   - for adding force (displayed on the left corner) click on the bone
   name with left button

   - for changing force value use ('x'+ 'Page Up'), ('y' + 'Page Up'),
     ('z' + 'Page Up') to increase proper values or ('x'+ 'Page Down'),
     ('y' + 'Page Down'),('z' + 'Page Down') to decrease them


I'm now thinking about mixing animation physics controllers and
behaviour controllers, anyone was doing such a thing? I will apriciate
any tips.

 Piotr Obrzut

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