[ODE] how to debug and fix NAN values

Paweł Kmiotek lewapq at tlen.pl
Mon Nov 5 09:32:58 MST 2007


Hi, Hampa have you found the solution ? I have simliar problem.

I'm curious maybe you have found something that would help me.

Best regards,
Lewap


    Message: 9 Date: Tue, 23 Oct 2007 00:16:33 +0800 From: Hampa
    <hampa at toribash.com> Subject: Re: [ODE] how to debug and fix NAN
    values To: "ODE Mailing List ((E-mail))" <ode at ode.org> Message-ID:
    <E14E58FC-CE2C-4A46-BA7E-4003A5AD089B at toribash.com> Content-Type:
    text/plain; charset="us-ascii" Hi Bram, It is the dNormalize4 (b->q)
    in void dxStepBody (dxBody *b, dReal h) in util.cpp. This is called
    from dInternalStepIsland_x2. I checked the values when entering the
    dxStepBody function and (depending on scenario) the lvel, avel, facc
    or tacc values have ended up as nan. With this I think I need to
    figure out where in dInternalStepIsland_x2 the values are
    introduced. /hampa On 22 Oct 2007, at 11:45 PM, Bram Stolk wrote:
>     > Run the app in a debugger.
>     > You wil get a call-stack.
>     >
>     > We would like to know in what part of the code, the normalization  
>     > was called.
>     >
>     > When I got this error, it was because I had a triangle that had a  
>     > zero-length edge.
>     > Thus, two vertices co-incided.
>     >
>     >   Bram
>     >
>     >
>     > On 10/22/07, Hampa <hampa at toribash.com> wrote:
>     > Hi,
>     >
>     > Every now and then my simulation produces NAN values, usually during
>     > collisions using hi velocity objects.
>     >
>     > In the debug build (lastets 0.9 svn checkout) I get asserts in:
>     > ODE INTERNAL ERROR 1: assertion "bNormalizationResult" failed in
>     > _dNormalize4() [../../include/ode/odemath.h]
>     >
>     > What is the recommended way to debug and fix this kind of problems?
>     >
>     > cheers,
>     > hampa
>     >
>     > _______________________________________________
>     > ODE mailing list
>     > ODE at ode.org
>     > http://ode.org/mailman/listinfo/ode
>     >
>     >
>     >
>     > -- 
>     > Zapp: Captain's log, stardate...er..
>     > Kif: Ohhh. April 13th.



More information about the ODE mailing list