Is it possible to customize the ZoomPanelNavigator further?
I have seen in the examples that I can change color and size.
But can I change the look of the buttons and the slider or use my own images?
There are many ways to customize the ZoomPanelNavigator.
As demonstrated in the samples, the colors can be changed with using Ab2d.Common.ZoomPanel.CommonNavigationResources.Instance.SetMainColors method.
To change the buttons in the navigation circle, you can access them from ZoomPanelNavigator.UsedNavigationCircle - this will give you the NavigationCircle object with properties that represent the buttons.
Because ZoomPanelNavigator is created with using standard WPF templates, you can provide your own template for the control and customize it in any way you want. To see the XAML for original template, see the Generic.xaml file that is installed into Themes folder in Ab2d.Controls.ZoomPanel installation folder. This will allow you to change the things you want to change and preserve the others.
See internet on how to provide different template for WPF controls.