Editing Vtk/Quadric (section)

===vtkSampleFunction===

As implemented in this example visualization, this module assigns default values and behavior to all methods ''except'' one:
* SampleDimensions is specified by the three integers (30, 30, 30); this is presumably the number of (uniformly sized) grid cells in each of the three coordinate directions &#8212; respectively, (x, y, z) &#8212; that will be assigned values of the function, <math>~F_0(x, y, z)</math>.

While initially deciphering the behavior of this entire workflow, I wondered how the edges of the (black) bounding box were specified.  Simultaneously, I wondered over what range of values of x, y, and z the grid resolution of (30, 30, 30) was being stretched.  The answer to both of these questions is the same.  The function is sampled over the range of coordinate values &#8212; and the (black) bounding box is drawn at the edges of this sampled region &#8212; as specified by the vtkSampleFunction method, ModelBounds.
* By experimentation, I discovered that the ''default'' coordinate values assigned to Modelbounds are, for x, y, and z, respectively, (-1.0, 1.0), (-1.0, 1.0), and (-1.0, 1.0).  By assigning, instead, values of (0.0, 1.0), (0.0, 1.0), and (0.0, 1.0), precisely one octant of the original configuration is displayed.