This operator generates an anti-aliased vein pattern that can be used in any VEX context.
The most important parameter is the Vein Projection type. The Linear
projection generates stripe-like veins to which noise is added to
resemble a marble-like pattern. The Cylindrical projection generates
radial veins, also perturbed by noise, which yield a wood-like pattern
if the Vein Direction (
vdir) is given a predominantly Z bias, such as
(0, 0, 1). The Spherical projection is useful for simulating agate-like
patterns and other layered material cross-sections.
The Vein Direction (
vdir) input, used with the Linear and Cylindrical
projection types, determines the overall orientation of the veins. To
better visualize the general vein orientation, you can temporarily
reduce the Vein Frequency (
vfreq) and the Noise Frequency (
The Vein Frequency (
vfreq) input controls the number of veins in the
pattern by varying the "s" parametric value of the Ramps operator called
internally. For wider or thinner veins, vary the Vein Attenuation
vatten) input. Vein Spacing (
vspacing) works similarly to Vein
Frequency in that it influences the number of veins in the pattern,
except it works not with "s" but with the frequency of the ramps. In
vfreq is a domain multiplier, while
the stripe frequency given a domain.
The Even Softness (
evensoft) toggle determines whether the veins should
attenuate softly on both sides of the vein backbone, or end sharply on
one side. This feature may become useful in distinguishing between
marbles, which have overall soft veins, and some types of wood, whose
rings have a distinct one-sided sharpness.
Make sure at least the Position (
pos) input is connected in order to
notice any pattern. The easiest way to accomplish this is to pipe the
P into the
pos input. Typically, however, you will
use Rest Position or UV Space Change as inputs into
pos. If you do
P, you will find it in the Global Variables operator.