I cloned the repo of citysim from bitbucket and ran the simplecity.world. Everything looks really great; only there is a strange occurrence when adding models via the GUI. The models seem to hover above the ground; and this occurs for the primitives as well as other models. See picture. C:\fakepath\floating_sphere.png

Any idea on how to correct this? Gravity is turned on; when positioned high above the ground, models fall but stop short above the ground; as though there is some invisible plane.