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|  | CheckEikonal (const GridT &grid, const ValueType &_min, const ValueType &_max) | 
|  | Constructor taking a grid and a range to be tested against. 
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|  | CheckEikonal (const CheckEikonal &other) | 
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| bool | operator() (const ValueType &v) const | 
|  | Return true if the value is smaller than min or larger than max. 
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| bool | operator() (const TreeIterT &) const | 
|  | Return true if zero is outside the range. 
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| bool | operator() (const VoxelIterT &iter) const | 
|  | Return true if the norm of the gradient at a zero-crossing voxel location of the iterator is out of range. 
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|  | 
| std::string | str () const | 
|  | Return a string describing a failed check. 
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|  | 
template<typename GridT, typename TreeIterT = typename GridT::ValueOnCIter, typename StencilT = math::WenoStencil<GridT>>
struct openvdb::v12_0::tools::CheckEikonal< GridT, TreeIterT, StencilT >
Checks the norm of the gradient at zero-crossing voxels against a range. 
CheckEikonal differs from CheckNormGrad in that it only checks the norm of the gradient at voxel locations where the FD-stencil crosses the zero isosurface!