[away3d] Reverse Collada Animation Away3D 3.4.0

[miles]

hi
at first i use old Awya3D because i need use FlarToolKit. It seems the
last Away3D 3.5.0 doesn't work with it.
so i need to reverse animation i my collada model
code:

        if(animDirection==-1 && animTimer>0){
                animTimer+=animDirection/30;
                skinAnimation.update(animTimer, true);
        }else if(animDirection==1 && animTimer<2.8){
                animTimer+=animDirection/30;
                skinAnimation.update(animTimer, true);
        }

so playing forward is ok, but when i try play reverse it's stop at
last frame. in trace animTimer working
may be how i can make reverse animation in Away3D 3.4.0?
thanks