Built with Unity, so you need the plugin and allow it to run. Drag and release to clip.
For Kingdom, I built a depth-based outline shader. It is similar in a sense to SSAO because it uses the depth buffer (though not the normals) to compute pixels that are inside a 'fold' and make those darker. Somewhat like Unity's built-in "Crease Shading", except it does not create drop shadows if the depth difference is too high, so it will not shade the sky/background or objects that are far behind others. We ended up not using this for Kingdom though. Press space to highlight the shaded pixels.