I know that the general form of a 2D projective transformation is following rational linear mapping: $(u, v) \mapsto (x, y)$
$ x = \frac{\mathit{a}\mathit{u}+\mathit{b}\mathit{v}+c}{\mathit{g}\mathit{u}+\mathit{h}\mathit{v}+i}\\ y = \frac{\mathit{d}\mathit{u}+\mathit{e}\mathit{v}+f}{\mathit{g}\mathit{u}+\mathit{h}\mathit{v}+i} $
What is its 3D version?