What's always bothered me about these kinds of animations is that there is a grid of straight lines, but none of the objects actually follow these grid lines. I

What's always bothered me about these kinds of animations is that there is a grid of straight lines, but none of the objects actually follow these grid lines. Instead, the geodesics they follow are determined by the topology of the deformed surface, invoking the viewer's intuitive understanding of gravity...in order to understand the unintuitive formulation of it. But, as you say, I haven't seen better.