The Groom Asset enables you to create textures based on the strands data from your imported grooms. You can generate a follicle mask for your skeletal mesh to better blend hair with its mesh surface. You can also create multiple strands textures that can be used to create a hair mesh or hair cards.
To get started, follow these steps:
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Right-click your Groom Asset in the Content Browser.
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Choose the type of texture you want to create: Create Follicle Texture and Create Strands Texture.
Follicle Texture
The Follicle texture contains a small distance field of the roots, which allows some effects within the shaders of the underlying surface materials to be captured from the Skeletal Mesh. The generate texture contains multiple channels to store texture information. You can choose several grooms at the same time to fill these channels in the generated texture.
When you choose Create Follicle Texture, the Groom Follicle Mask Options window opens. Choose your options and click Create to generate your follicle texture mask. These textures will be saved in the same location as your Groom Asset.
| Property | Description |
|---|---|
| Resolution | The texture resolution of the follicle mask. The resolution is rounded to the closest power-of-two size, for example, 256, 512, and 1024. |
| Root Radius | The size of the root of the strand in the generated follicle mask, measured in pixels. |
| Grooms | |
| Groom | The Groom Asset to be used to generate the follicle texture mask. |
| Channel | The color channel of the texture mask to store this groom's follicle texture mask in. |
In the following example, two grooms have been selected with the first groom outputting its follicle mask into the R (or red) channel, and the second outputs a follicle mask to the G (or green) channel.
Click image for full size.
Strands Textures
The Strands textures includes several textures generated from your groom to be applied to a specified hair mesh.
When you choose Create Strands Textures, the Groom Strands Textures Options window opens. Choose your options and click Create to generate your strands textures. These textures will be saved in the same location as your Groom Asset.
| Property | Description |
|---|---|
| Resolution | The texture resolution of the strands textures that are generated (tangent, opacity, depth, and attribute). The resolution is rounded to the closest power-of-two size, for example, 256, 512, and 1024. |
| Trace Type | Choose the direction of the traces that should be performed for the projection when generating the strands textures.
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| Trace Distance | The distance from the mesh surface until the hair is projected onto the mesh. |
| Mesh Type | Selects the type of input mesh that is used for tracing: Static Mesh or Skeletal Mesh. |
| Static Mesh | The Static Mesh asset on which the groom strands will be projected on to generate textures. Requires you to set the Mesh Type to Static Mesh. |
| Skeletal Mesh | The Skeletal Mesh asset on which the groom strands will be projected on to generate textures. Requires you to set the Mesh Type to Skeletal Mesh. |
| LOD Index | The level of detail mesh index on which the texture projection is performed. |
| Section Index | The section of the mesh on which the texture projection is performed. |
| UV Channel Index | The UV channel index to use for texture projection. |
| Group Index | The groom index which should be baked into the textures. When the array is empty, all groups are included by default. |
The result is several texture assets that include depth, attributes, opacity and tangent, with which you can apply to a hair mesh. Below are two example textures output from the groom mapped to a hair mesh.
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| Depth Texture | Tangent Texture |
An example hair mesh representation of the groom with the generated textures applied:
Click image for full size.