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5.5.1 Point/implicit algebraic surface intersection

The mathematical description for a point and an implicit surface $ f(\mathbf r)=0$ intersection is given by
$\displaystyle \mathbf{r}_0 \cap f(\mathbf{r})=0\;.$     (5.31)

Similar to the point implicit curve intersection case, the condition for intersection is given by

$\displaystyle \vert f(\mathbf{r}_0)\vert < \varepsilon, \quad
\frac{\vert f(\mathbf{r}_0)\vert}{\vert\nabla
f(\mathbf{r}_0)\vert} < \delta\;,$     (5.32)

where $ \varepsilon, \delta$ are small positive constants, provided $ \vert\nabla f(\mathbf{r}_0)\vert\neq 0$ .



December 2009