Flat ground textures can be wonky when viewed from a particular angle. I'd check the readme on the ground texture set for the best render settings. It's possible during the animation you might need to change the ground setting the closer the camera is to the ground (or fiddle with the camera setting). You could morph the ground a bit to give it some depression and rises. Tony Vilters has a great tutorial about how to create the ground morphs.

https://www.youtube.com/watch?v=IQtTmkkAjXc

Changed during my typing. Sam's on to the right answer.

The dust settled, thinking "what a fine home, at least for now" not realizing that doom would soon be coming in the form of a vacuum cleaner.