[ODE] Look at my Humanoid Example

[Gene Ruebsamen]

Sure, if my code can help you in your game, feel free to use it!
I'm still trying to work out the stability issues, can anyone comment on my
previous post?  (Russ? =)

Thanks,

Gene

> -----Original Message-----
> From: McEvoy, Nick [mailto:nick.mcevoy@dsto.defence.gov.au]
> Sent: Thursday, February 14, 2002 1:12 PM
> To: 'gene@erachampion.com'
> Subject: RE:[ODE] Look at my Humanoid Example
>
>
> Ouch ... bit of a tumble .... cool stuff but !!!  Now you got to
> get him to
> stand up and walk.  :-)
>
> Sorry I haven't got any stability notes for you ... I just wanted to say
> keep up the good work.
>
> Your example code might come useful in my game one day (if that is ok with
> you of course) !  :-)
>
> Nick
> http://members.ozemail.com.au/~ndmcevoy/
> _________________________________________
>
> Message: 5
> From: Gene Ruebsamen <gene@erachampion.com>
> To: ode@q12.org
> Date: 13 Feb 2002 19:03:51 -0800
> Subject: [ODE] Look at my Humanoid Example
>
> Hello Everybody,
>
> I've created a humanoid figure in ODE. I used ball & socket joints for
> the arm and leg sockets, and hinges for the elbows, knees, and ankles.
>
> You can view a demo at: www.realtyroad.com/gene/
>
> My problem is... stability.  I am using ODE 0.3 and am having a horrible
> time with stability. I am dropping my humanoid from an altitude onto a
> staircase.  Depending upon the initial starting conditions (altitude,
> gravity, etc), either he will tumble down the staircase (as expected) or
> he will start to gyrate and oscillate (usually in the legs) and even
> explode.  The instability usually occurs when a joint hits its stop (as
> far as I can tell).
>
> At one time, I had the simulation fairly stable, using a global ERP of
> 0.1 and a global CFM of 0.01; however, looking through the docs, I think
> Russ recommended an ERP of between 0.2 and 0.9.  So I decided to set the
> ERP and CFM in each joint individually. I currently have it set at 0.5
> and 0.01 respectively.  Can I only achieve stability with such a low ERP
> of 0.1?  And if so, won't that introduce alot of joint error?
>
> Another question I have is with regards to motors.  When a powered joint
> reaches it's stop, must I shut off the motor (ie, set FMax to 0)?  Or is
> there a way to have the stop override the motor?  Right now, I have all
> my joints Fmax at 0; however, at one time I was running with FMax at
> 0.01 and velocity at 0 to simulate friction.
>
> The source is posted on the page above, in case anyone is curious, and
> wants to critique it for me... =) and hopefully help me solve the
> instability problems.
>
> Thanks!!
>
> Gene Ruebsamen
>