3ds Max 2012 Bible - Kelly L. Murdock [330]
Working with Hair
Applying hair to an object is as easy as selecting an object and choosing the Hair and Fur WSM modifier, which is found in the Modifiers⇒Hair and Fur⇒Hair and Fur WSM. After hair is applied to an object, you can use the parameters in the Modify panel to change the hair's properties.
Growing hair
Hair can be grown on any geometry surface, including splines, by simply applying the Hair and Fur WSM to the selected object. When the Hair and Fur modifier is first applied to an object, it is applied to the entire surface of the selected object, and when it is applied to a set of splines, the hair appears between the first and last spline.
If you want to localize the hair growth to a specific area of the object, you can make a subobject selection using the controls in the Selection rollout. The available subobjects include Face, Polygon, Element, and Guides. After making a subobject selection, click the Update Selection to display the guide hairs only in the selected area in the viewports. Figure 29.1 shows hair grown on a man's face to create a beard.
Tip
After taking the time to make a subobject selection, create a selection set for the hair area for quick recall. •
FIGURE 29.1
By making a subobject selection, you can control precisely where hair is grown.
Applying hair to a single spline doesn't create any hair, but if multiple splines are included as part of the same Editable Spline object, then the hair is interpolated between the various splines in the order they are attached following the spline's curvature. This provides a great way to add special features like a ringlet to an existing set of hair.
Setting hair properties
Several rollouts of properties can be used to change the look of the hair. The General Parameters rollout, shown in Figure 29.2, includes settings for the overall Hair Count, the number of Hair Segments between adjacent splines, the number of Hair Passes, Density, Scale, Cut Length, Random Scale, Root and Tip Thickness, and Displacement. The Hair Count value sets the total number of hairs for the given geometry. Higher values take longer to render but produce more realistic hair. The Hair Passes sets the number of render passes to use for determining hair transparency. The higher the Hair Passes value, the wispier the hair looks. The Rand Scale value provides a random amount of scaling for a percentage of hairs to look more natural. The Displacement value sets how far from the source object the hairs grow and can be a negative value.
Caution
Although the Hair Count value can accept huge numbers, adding a large number of hairs takes a long time to render and can really slow your system. •
FIGURE 29.2
Hair properties can be altered using the General and Material Parameters rollouts.
The buttons to the right of most of the parameters in the General Parameters rollout let you add a map to control the property with a grayscale bitmap. Figure 29.3 shows a simple plane object mapped with a bitmap used to control the hair density. The black areas of the bitmap have no hair growth, but the white areas have maximum growth. This provides a way to create patchy hair on a character or creature.
The Material Parameters rollout, also shown in Figure 29.2, includes settings for the Occluded Ambient value, controlling the tip and root colors, Hue and Value Variations, the addition of mutant hairs, percentage to include, and specular and glossiness settings. The Occluded Ambient value sets the contrast for the hair lighting. Smaller values have a stronger contrast, and higher values appear more washed out. The Hue and Value Variation values define a percentage that the hair color can deviate from the specified color to give the hair a more natural coloring. The Mutant percentage defines the percentage and color of hairs that are discolored, such as white hairs.
Note
The Occluded Ambient property is applied as an