Inside curved spaces

Visualizations of some 3D curved spaces made from curved 2D surfaces with one orthogonal dimension added, like S^2 x R. Visualizer source code and binaries: Written in D programming language. One important feature of D is used: compile-time function execution. To describe a world I just encode the formula of embedding 2D manifold (u,v) into 3D space (x,y,z). Then at compile time my symbolic computation module takes this expression, finds its partial derivatives