The HairTG – Hair Clump Tool 1.1 update brings four new features. One in particular, thickness control, is especially useful to create stylized hair.
Hair strand group rotation
Each parent hair strand can be rotated independently. Child strands attached to each parent are also rotated accordingly. Along with the existing hair group X/Y offset setting, it is now possible to precisely position and orient each hair group.
A hair combing functionality enables further control as to how child hair strands are positioned relatively to their parent. Combing is controlled with two parameters:
- Power: the higher the power, the more child hair strands will be ordered and aligned to the strand root. Used in conjunction with the child root drift control (i.e. children horizontal drift at control point 1), it is possible to widen the spacing between combed hair strands.
- Comb length: combing can be applied partially starting from root. The comb length defines how long combing will occur starting from the clump root.
Reducing the vertical child drifts to 0, it is possible to have child hair strands exactly following the shape of the parent hair strand, and their spacing is controlled by the horizontal drift at control point 1 (root).
Child hair strands dispersion attenuation
This feature is a bit like combing but not exactly in the same way. It also applies to child hair strands. When no attenuation is being used, the child hair strand horizontal drift from parent is calculated independently at each control point with no relationship between them. When the random drift range is large, this can create a wide dispersion of hair when the picked random values are very different for each drift. The attenuation brings in a relationship between the drifts at each control point, in such a way the random drift will be a depart from the previous drift instead of being totally uncorrelated. This way, child hair strands are more realistically flowing along the hair clump. Parameters are the following:
- Dispersion attenuator: at 0, no attenuation is performed. As the value is raised, child hair strands horizontal drifts at each control point are more and more correlated between each other and the random factors associated to each of them are less and less effective. This makes the hair strands more closely following the overall flow of the hair clump.
- Dispersion towards tip: this modulates the attenuation function of the control point position. For control points closer to the tip of the hair, attenuation will be reduced, so more freedom will be given to the hair dispersion.
Hair strand thickness (i.e. dynamic pattern sizing) can now be controlled in a similar way as the fade effect. We can define lengths for the top (root) and bottom (tip) thickness variations as well as a midpoint defining where the top and bottom lengths end/begin. We can also define a sizing factor to shrink or widen thickness at each end as well as a variation type. Parameters are as follows:
- Thickness variation top/bottom: a multiplier for the pattern size to use along the top/bottom variation lengths. If lower than 1 the thickness will be diminished, if greater than 1 it will grow.
- Thickness variation type: Linear will generate a linear thickness variation along the variation length, this is a straight progression. Cosine will generate a more curvy variation. A third variation type is also available, Xn, which is an x^n interpolation type with n configurable as variation shape. This can be used to create steep variations at the beginning of the variation space.
- Thickness variation length top/bottom: the length onto which the thickness will vary in respectively the top and bottom spaces. These spaces are defined by the midpoint.
- Thickness variation length midpoint: a midpoint telling where the top length ends and where the bottom length begins.
- Thickness variation length random: brings a random factor to the thickness length for each strand so they are not all exactly the same.
Thickness control is key to produce stylized hair, the picture above shows a few demos of what can be done with it.