Grooms can have multiple levels of details (LODs) and each can use a strand, card, or mesh for their representation. The number of LODs a groom has is set up in the LOD panel of the Groom Asset Editor. Card and mesh geometries are managed in their own Cards and Meshes panels. In each panel, you can add new entries and configure the mesh geometry and its material.
Cards Panel
The Cards panel is where you set the cards mesh, textures, and mapping to specific hair groups and LODs. Statistical information about each card mesh is displayed at the top of each entry for the number of cards and vertices it contains.
When importing a mesh used as card geometry, you must choose the Guide Type to for each card mesh:
- Generated guides generate deformation guides based on the mesh itself. These guides are run through the middle of each hair card geometry.
- Guide-Based uses the groom's guides for skinning the cards geometry by picking the closest guide for each card vertex.
The Textures section configures the input textures used for card geometry. Two different card layouts are available: Default and Compact. These layouts define how the attributes are packed for these textures. Attributes such as GroupID and Per-Point Color are automatically generated by voxelizing the strands and transferring the average value to each card vertex.
 |
 |
| Groom Textures Default Layout | Groom Textures Compact Layout |
The textures in the list are automatically bound and sampled in a material when using the Hair Attributes expression. For more information on this material expression and its usage, see Groom Material.
The following properties are available in the Cards panel:
| Property | Description |
|---|---|
| Material | The assigned material used for card representation LODs. This material is picked from the list shown in the Materials panel of the Groom Asset Editor. |
| Guide Type | Choose the type of guides used for cards:
|
| Mesh | The mesh referenced by the card geometry. |
| Textures | |
| Layout | This setting determines how the attributes of the groom are packed into textures. You can choose between Card or Mesh Default and Compact. Default packs attributes separately into textures where it makes sense. Compact groups more attributes into fewer textures. |
| Depth | The depth texture used for the card asset. This texture is optional, but when set, the value is forwarded to the Hair Attributes node in the Material Editor. |
| Coverage | This texture is used for the card asset. This texture is optional, but when set, the value is forwarded to the Hair Attributes node in the Material Editor. |
| Tangent | This texture is used for the card asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Attributes: RootUV / CoordU / Seed | This texture is used for the card asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Material: Color / Roughness | This texture is used for the mesh asset. This texture is generated with the hair textures option on the Groom Asset. |
| Auxiliary | This texture enables user data to be transferred for the card asset. It is an optional texture. When this value is set, it is forwarded to the Hair Attributes** node in the Material Editor. |
| Group Settings | |
| Group Index | The group index on which this card's geometry is mapped. |
| LOD Index | The LOD index at which this card asset should be used. |
Hair Card Generator Plugin
This feature is experimental. Output results can vary depending on the complexity of the groom.
Creating these hair cards can be a difficult and time-consuming task, especially when trying to match the volume and styling of a strand based groom counterpart. The Hair Card Generator plugin makes this process simpler by converting strand based grooms to card based representations within the Groom Asset Editor.
 |
 |
| Original Strand Based Groom | Generated Card Based Groom |
To learn how to use this plugin and set it up, see Hair Card Generator.
Meshes Panel
The Meshes panel is where you set the mesh, textures, and mapping to specific hair groups and LODs. This panel lists all geometry but not all geometry is necessarily used.
The following properties are available in the Meshes panel:
| Property | Description |
|---|---|
| Material | The assigned material used for mesh representation LODs. This material is picked from the list shown in the Materials panel of the Groom Asset Editor. |
| Mesh | The geometry referenced for this mesh. |
| Textures | |
| Depth | The depth texture used for the mesh asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Coverage | This texture is used for the mesh asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Tangent | This texture is used for the mesh asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Attributes: RootUV / CoordU / Seed | This texture is used for the mesh asset. This texture is optional, but when set the value is forwarded to the Hair Attributes node in the Material Editor. |
| Material: Color / Roughness | This texture is used for the mesh asset. This texture is generated with the hair textures option on the Groom Asset. |
| Auxiliary | This texture enables user data to be transferred for the card asset. It is an optional texture. When this value is set, it is forwarded to the Hair Attributes node in the Material Editor. |
| Group Settings | |
| Group Index | The group index on which this mesh's geometry is mapped. |
| LOD Index | The LOD index at which this mesh's asset should be used. |
| LOD | |
| Minimum LOD | Specify the minimum level of detail to cook for all platforms, or specify minimums for individual platforms by adding them to the array using the Add (+) icon. |