Change model3dgroup associated to model3d

Hi, my project started from your kinect example. I'm trying to do a kinect recorder and player.

all is going well but now i need to reproduce my video, obj after obj.
in public MainWindow() i do this:

this.KinectGroup = new Model3DGroup();
Model = KinectGroup;

and the rendered model is the kinectGroup i set. All fine!
but now i need to unbind that KinectGroup and use another group, the one i'm using to reproduce the "video"

This is my try:

Model3DGroup group = HelixToolkit.Wpf.ModelImporter.Load(extractPath + @"\model1.obj");
Model = new GeometryModel3D();
Model = group;

i tried to reinitialize the model and associate my group to it.. but this seems to do nothing! I still see the older group (my 2 kinects input) while it still refresh itself :(

how i can do this? thank you!

Solved by removing kinectGroup's children and adding the new ones. Maybe not optimal solution but it works :\