Re: [Plib-users] TweenController in plib

[Steve B. <sjb...@ai...>]

Rolf Jakob wrote:

> I try to get a tween controller to work with the current CVS snapshot. What I 
> did :
> Used exposer to have some animation and saved a tweened model with a bank 
> every second.
> Load the model using ssgLoadSSG resulting to a hierarchy starting with an 
> ssgEntity. In fact this should be a ssgTweenController.

Well, ssgEntity is an abstract base class in SSG - you can't have a 'pure'
ssgEntity - it's always some kind of derived class.

> Create a ssgTransform and add the tween controller as a kid to be able to 
> transform the model in the scene.
> Use the ssgTransform for transformation and the ssgTweenController for the 
> animation (this one has to be casted from ssgEntity).
> The animation has the default length of 10 seconds, so I should have 10 banks.

Sounds reasonable.

> The problem is I cannot see the model moving, it's always in its first 
> position. A debug shows that the bank selecting factor travels from 0.0 to 
> somewhere near 10 and restarts at 0.0, so that should be ok.

Indeed.

> I'm quite sure I miss something very simple, but what ?
> Is the way I got the model into the scene the way it should be ? Is the type 
> of the root node preserved from exposer through a ssgLoadSSG() ?

Yes - it should be.

> Code sniplets:
> // global
> ssgTransform *femme=0;
> ssgEntity *femme_obj;
> 
> // init
> femme=new ssgTransform;
> femme_obj=ssgLoadSSG("player-female_tweened.ssg");
> femme->addKid(femme_obj);
> sgCoord fc;
> sgSetCoord(&fc,1.67,0.126,0,90,0,0);
> femme->setTransform(&fc);
> scene->addKid(femme);
> 
> // redraw
> float bank=(frameno%140)/14.0;
> ((ssgTweenController *)femme_obj)->selectBank(bank);
> cerr << "bank : " << bank << endl;


Well, that *looks* OK.

One of my programs does this:

   body_tween = new ssgTweenController () ;
   body_tween  -> addKid ( ssgLoad ( "body.ssg"  , loader_opts ) ) ;

...and then...

void update_motion ()
{
   static int frameno = 0 ;

   frameno++ ;

   body_tween -> selectBank ( (float)frameno/100.0 ) ;
}

...so I think you are basically doing the right thing - you must have
a bug somewhere.  I guess you should do:

    cerr << femme->getTypeName() << endl ;

...to be sure that you really have an ssgTweenController.


----------------------------- Steve Baker -------------------------------
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