\( \boldsymbol{x}(u, v) = \begin{pmatrix} a \cos u \hskip 0.1em \cos v \\ b \cos u \hskip 0.1em \sin v \\ c \sin u \end{pmatrix} \)

\( \left( - \dfrac{4 \pi}{9} \leq u \leq \dfrac{4 \pi}{9}, \, 0 \leq v \leq 2 \pi \right) \)

\( a = \) , \( b = \) , \( c = \) 更新

\( (0.1 \leq a, b, c \leq 10) \)