Source code is here.

This is a simple carousel that uses cubes instead of pictures.  It can be rotated by clicking on a cube.  I've used an image brush for the cube with the picture, a linear gradient brush, a radiant gradient brush, and no brush with a dark blue material.

The code can be easily modified to use other images or add more cubes, and even use different images on the same cube.  This all was done in WPF to demonstrate some basic 3D techniques.

My biggest hurdle was getting an image to show up when the code for adding the image was outside the main page.  I was getting errors about the image not being found in my debug directory when I had already added it to to my project as a resource.  By default, adding an image to the WPF project has the Build set to "Resource" which works fine for most apps.  After a lot of searching on the internet and trials and errors, I found that I had to set that image's Build to Content and Copy to Output Directory to "Copy always".