XGen interactive grooming Clump modifier attributes

Use a Clump modifier to globally generate large numbers of hair and fur clumps.

Clump Effect

Clump: Sets the strength of the clumping effect applied to the hairs. Increasing this value pulls surrounding hairs closer to the clump's center, which results in tighter clumps. You can use a mask to control the amount of clumping effect in specific areas of the groom. See Work with masks.
Clump Scale: Lets you scale the magnitude of the clumping effect along the length of the hair from root (left end of the ramp) to tip (right side of the ramp). For example, this lets you make the clumps tighter at the tips and more relaxed at the root.
See also Set attributes using ramps.
Clump Volumize: When on, the volume around each hair clump increases so they can resist compression. Use this on small clumps.
Clump Variance: Lets you vary the clumping effect by pushing individual hairs away from the center of their clump towards other nearby clumps. Increase this value to breakup uniform looking clumps in the groom.
Preserve Length: Blends the modified hair length due to the clumping effect with the hair's original length. When set to 0 the hairs stretch to the clump point. When set to 100 the hairs do not stretch past their original length and reach towards the clump point as far as they can.

Clump Points

Randomness: Adds randomization to the distribution of clump points on the mesh. When set to 0, the clump points are uniformly positioned. Increasing this value adds more randomization to their distribution on the bound mesh. Use Randomness to breakup uniformity in the groom.
Density: Sets the number of clump points per unit area created on the bound mesh. Increasing this value creates more hair clumps.
Density Mask: Lets you use a mask or an expression as a multiplier to vary the density of clump points on the mesh.
Seed: Sets the seed value for randomly generating clump points.

Clump Map

Auto Update

When on, the clump map gets automatically updated after you make changes to any Clump modifier attribute.

Radius Variance

Randomizes the radius of the hair clumps throughout the groom. You can also use a texture map or an expression node to add randomization. Use this to breakup uniformity in the groom.

Map Subdivision Level

Sets the resolution of the clump map. Higher values increase the number of cells in the clumping map. Increasing this value gives more definition to the hair clumps.

Use Control Map

Turn on to enable the use of control maps, such as other Clump modifiers or painted texture files to control the hair position of hair clumps. Use control maps when:

The description uses guides that are controlled by a region map. In this case, you can select the region map as the control map. This ensures that the hair clumps are generated within the boundaries specified by the region map. Otherwise, the hair clumps may cross the region map boundaries creating an undesired effect, such being generated in the middle of a hair part.
The current Clump modifier is creating secondary hair clumps. In this case, specify the primary Clump modifier as the control map. This ensures that the secondary clumps generate inside the primary hair clumps.
You want additional control over the placement and scale of the hair clumping effect. In this case, you can select a texture file or paint a texture to control the hair clumps

Control Using

Lists the Clump modifiers or region maps that can be used as a control maps for the current Clump modifier. For example, if you are creating secondary hair clumps with the current modifier, you can select the primary Clump modifier as the control map. You can also use a texture file or painted texture as a control map by selecting Custom Map.

Custom Map

Click this icon

and browse to the location of the texture file you want to use as a control map. Click this icon

to paint a texture on the surface to act as the control map (see Control hairs by painting a mask on the mesh).

Control Mask

Let's you use a texture file or painted texture to scale the influence of the selected Control Map. Use a control mask to specify where the control map has greater and lesser effect.

See Work with Masks.

Update Clump Map

When Auto Update is off, click this option to regenerate the clump map based on any new attribute values.

Advanced Shape

Flatness: Compresses the space between individual hairs to create a flattening effect. Increasing this value reduces the amount of space between the hairs.
Flatness helps create the natural tendency of hair clumps to flatten out towards the tips in long hair. Use the Flatten Scale ramp to make fine adjustments to this effect.
Offset: Sets an offset between the hair clumps and the clump points, which are at the center of the clump. Use this to allows space for hair curls, coils, and spirals. Higher values increase the offset distance. Use the Offset Scale ramp to set Offset along the length of the hairs.
Curl: Applies curl to the hairs. Higher values increase the tightness and number of curls. Use the Curl Scale attribute to define the shape of the curls and coils.
Orient: Lets you adjust the orientation, in degrees, of the shape generated by Flatness, Offset, and Curl. For example, you can use this attribute to change the direction of the hair curls. The default range is 0 to 360 degrees, but you can type values outside of this range. Use the Orient Scale attribute to adjust orientation along the length of the hairs.
Flatness Scale: Lets you scale the Flatness value at various points along the length of each hair from root (left end of the ramp) to tip (right side of the ramp). For example, use this to compress hairs more at their tips and less at the root.
See also Set attributes using ramps.
Offset Scale: Lets you scale the Offset distance at various points along the length of the hair from root (left of the ramp) to tip(right side of the ramp).
See also Set attributes using ramps.

Secondary Effects