Android Programming The Big Nerd Ranch Guide by Bill Phillips, Chris Stewart, Kristin Marsicano (z-lib.org)

Material Surfaces

Instead, surfaces exist and maneuver around one another in 3-D space. They can move up toward your
finger, or down and away (Figure 35.2).

Figure 35.2  A material design in 3-D space

To animate one surface across another, you move it up and across the other surface (Figure 35.3).

Figure 35.3  Animating one surface over another