[osg-users] Speeding u/down animation smoothly

[Julien Valentin]

set _firstframe to 0 to think in animation time base (not in simulation time)
let timemultiplier to 1
and set latesttime to what you want(in animation time base)

then setup

mp3butcher wrote:
> 
> Code:
> float getAnimationTime{return ((_latestTime-_firstTime)-_timeOffset)*_timeMultiplier;}
> 
> 
> 
> so you'll have to do math!!
> ;)
> 
> 
> dhhabyc wrote:
> > Hello,
> > 
> > I'm trying to sppeding up/down an animation using AnimationPathCallback. The idea is to pause/speed/up/down the animation using key strokes, for this I have a GuiEventHandler derived class and a NodeVisitor derived class. So far I've playing round with the base clases AnimationPath and AnimationPathCallback methods get/setStartTime, get/setTimeOffset, get/setLastTime and get/settimeMultiplier with no success.
> > 
> >  I found http://forum.openscenegraph.org/viewtopic.php?t=10014 but my implementation still jumps around when speeding up/down:
> > 
> > 
> > Code:
> > void AnimationVisitor::apply(osg::Transform& transform)
> > {
> > 	osg::AnimationPathCallback* apc = dynamic_cast<osg::AnimationPathCallback*>(transform.getUpdateCallback());
> > 	
> > 	if (apc)
> > 	{
> > 		osg::AnimationPath * path = apc->getAnimationPath();
> > 		int key = getKey();
> > 		double lambda;
> > 		switch (key)
> > 		{
> > 		case osgGA::GUIEventAdapter::KEY_Space:
> > 		{
> > 			bool is_paused = apc->getPause();
> > 			apc->setPause(!is_paused);
> > 			std::cout << "Animation time: " << apc->getAnimationTime() << std::endl;
> > 			std::cout << "\tPause: " << !is_paused << std::endl;
> > 			std::cout << "---------------------------" << std::endl;
> > 			break;
> > 		}
> > 		case osgGA::GUIEventAdapter::KEY_Right:
> > 		{
> > 			double last = path->getLastTime();
> > 			double first = path->getFirstTime();
> > 			lambda = apc->getTimeMultiplier();
> > 			double simTime = last - first;
> > 			double currOffset = apc->getTimeOffset();
> > 			double offset = simTime - (simTime - currOffset) / 1.1;
> > 			apc->setTimeMultiplier(1.1*lambda);
> > 			apc->setTimeOffset(offset);
> > 			std::cout << "Animation time: " << apc->getAnimationTime() << std::endl;
> > 			std::cout << "\tSpeed up: : " << lambda * 1.1 << std::endl;
> > 			std::cout << "---------------------------" << std::endl;
> > 			break;
> > 		}
> > 		case osgGA::GUIEventAdapter::KEY_Left:
> > 		{
> > 			double last = path->getLastTime();
> > 			double first = path->getFirstTime();
> > 			lambda = apc->getTimeMultiplier();
> > 			double simTime = last - first;
> > 			double currOffset = apc->getTimeOffset();
> > 			double offset = simTime - (simTime - currOffset) * 0.9;
> > 			apc->setTimeMultiplier(0.9*lambda);
> > 			apc->setTimeOffset(offset);
> > 			std::cout << "Animation time: " << apc->getAnimationTime() << std::endl;
> > 			std::cout << "\tSpeed up: : " << lambda * 0.9 << std::endl;
> > 			std::cout << "---------------------------" << std::endl;
> > 			break;
> > 		}
> >                 default:
> > 			break;
> > 		}
> > 		
> > 	}
> > 	traverse(transform);
> > }
> > 
> > 
> >    
> > 
> > Can anyone give some pointers about how to achieve a smooth speeding transition? I look up in the source code of both classes involved (AnimationPath and AnimationPathCallback) but I havent been able to figure out a solution. What can I do? or What am I missing?
> > 
> > Thank you!
> > 
> > Cheers
> 


------------------------
Twirling twirling twirling toward freedom

------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=75289#75289