ParametricPlot3D[{r Cos[theta],r Sin[theta],Sin[theta/2]^2},{r,0,1},{theta,0,2 Pi},ViewPoint->{1,1/2,7/8}]

ParametricPlot3D[{r Cos[theta],r Sin[theta],Sin[theta/2]},{r,0,1},{theta,0,4 Pi},ViewPoint->{1,1/2,7/8}]

ParametricPlot3D[{r Cos[theta],r Sin[theta],Sin[theta/2]},{r,0,1},{theta,0,4 Pi},ViewPoint->{1,1/4,1/4}]