vtkBooleanTexture - generate 2D texture map based on combinations of inside, outside, and on region boundary
vtkBooleanTexture is a filter to generate a 2D texture map based on
combinations of inside, outside, and on region boundary. The "region" is
implicitly represented via 2D texture coordinates. These texture
coordinates are normally generated using a filter like
vtkImplicitTextureCoords, which generates the texture coordinates for
any implicit function.
vtkBooleanTexture generates the map according to the s-t texture
coordinates plus the notion of being in, on, or outside of a
region. An in region is when the texture coordinate is between
(0,0.5-thickness/2). An out region is where the texture coordinate
is (0.5+thickness/2). An on region is between
(0.5-thickness/2,0.5+thickness/2). The combination in, on, and out
for each of the s-t texture coordinates results in 16 possible
combinations (see text). For each combination, a different value of
intensity and transparency can be assigned. To assign maximum intensity
and/or opacity use the value 255. A minimum value of 0 results in
a black region (for intensity) and a fully transparent region (for
transparency).