Creating Face Accessories

A face accessory is a cosmetic Accessory that attaches to the head and can include items such as hair, eyebrows, glasses, and facial hair. To create a face accessory that is compatible with animateable heads, you use a similar design process as layered clothing to allow your accessory model to deform and stretch on a head when the head is posed or animated.

To create a face accessory, use a third-party modeling tool, such as Blender or Maya, to create a 3D model with the following requirements:

  • The accessory model must meet Studio's mesh requirements.
  • The model must be parented (Blender) or bound (Maya) to an R15 character rig.
  • The model must include an inner and outer cage.

This guide covers the basic process in Blender for applying rigging and cage data to a basic reference model using the Cubie model referenced in Creating Basic Heads.

Reference Files

The following are face accessory reference files, including all example files from this guide:

Name Description
Cubie-Complete.fbx The complete Cubie reference character, from Creating Basic Heads. This file is ready for import into Studio.
Cubie-Cage-Only.fbx The full body cage mesh of the Cubie reference character. This includes the inner and outer cage meshes.
Cubie-Eyebrow-Geo.fbx A standalone eyebrow model, designed for the Cubie model.
Cubie-Eyebrow-Rigged-And-Caged.fbx The Cubie eyebrow model, correctly rigged and caged following the instructions in this guide. This file is ready for import into Studio.
Cubie-Hawk-Hair.fbx A hair model reference, designed for the Cubie model.
Creating-Face-Accessories-Reference-Files.zip A collection of all the provided reference files.

Modeling

This guide uses a simple eyebrow reference as a demonstration for creating a face accessory. If rigging and caging a different model, ensure that your model meets the universal mesh and modeling standards for Studio import.

If creating your own model, consider the following guidelines:

  • Model your accessory with your character model for best results and fit.
  • When possible, try to match up the edges of your model geometry with the edges/vertices of the underlying head topology. This improves the deformation of the accessory with the underlying head model.
  • Some accessories, like eyebrows, can extrude or slightly intersect the character model mesh to achieve a certain cosmetic look.
  • When working with an accessory with multiple pieces, such as eyebrows, combine the meshes to a single mesh once the modeling and fitting is completed.
  • Face accessory meshes do not require a _Geo naming convention.

Rigging

You must rig your accessory to an R15 bone structure so the accessory can bend and deform along with your character's facial poses. After rigging, you can choose to immediately skin your model in your modeling tool, or you can transfer skinning data from your character to the accessory later in Studio by enabling Auto-Skin Transfer.

Project Setup

As an example in this guide, we are using the completed basic Head model from Creating a Basic Head and a simple eyebrow model in a new Blender project.

To set up your Blender project:

  1. Open a new General project in Blender.

  2. Select the default shape, camera, and lights, then press Delete.

  3. In the left-hand navigation of the Properties Editor, navigate to Scene Properties.

  4. In the Units section, change the Unit Scale to 0.01 and the Length to Centimeters.

  5. Import the character rig you intend to parent the accessory to, in this example: Cubie-Complete.fbx.

  6. To simplify the workspace, you can delete the R15 inner and outer cage mesh objects since you will later import a full-body cage in the Caging step.

  7. Import your accessory model, in this example: CubieEyebrow_Geo.fbx.

    1. If required, reposition the accessory model on the face.
    2. You can hide the armature temporarily to verify model placement.

Parenting Armature

Connect the mesh object to the character's armature by parenting the armature to the mesh object. To parent the armature:

  1. In Object Mode, hold shift and click the accessory model and then any of the character bones.
  2. Right click and select Parent, then select With Automatic Weights.

Optional Skinning

In a traditional modeling process, modelers will typically skin, or add vertex influences, to their rigged model. Depending on the complexity and design of your accessory, you can skip the skinning process in your modeling software and use Roblox's Auto Skin Transfer instead.

At this point, you can either continue directly to Caging, or apply skinning manually to your accessory by using modeling tools, such as Blender's Weight Paint or Transfer Weights to transfer skinning data from the Head_Geo to the accessory.

Caging

The caging process for face accessories is similar to caging layered clothing accessories and share the same modeling and caging requirements. After rigging, import a full-body inner and outer cage to your project, rename the cages, then stretch the vertices of the Outer Cage to cover the accessory model with minimal space.

To cage the eyebrow accessory:

  1. With Blender's .fbx importer, import Cubie-Cage-Only.fbx. This includes a single full-body inner and outer cage mesh for the Cubie model.

  2. Rename cages to begin with "CubieEyebrow" before the _InnerCage and _OuterCage affix.

  3. In Edit mode, extend the outer cage to fit over the accessory with minimal space. Use various material and viewing options to easily manipulate the correct vertices on the outer cage.

Optimization for Auto-Skin Transfer

Roblox's Auto-Skin Transfer feature is a convenient way to apply skinning onto your accessory mesh by transferring skinning data from the head or body of the character it is attached to. When enabled, this feature allows you to transfer the skinning data from the source geometry using the relationship of the accessory mesh geometry and the nearest surfaces of the mesh's inner cage. In some cases, such as larger or more complex accessories, you can ensure that auto-skin transfer only applies to specific parts of the body by removing unnecessary sections of the cage.

In the following example, a beard accessory is modeled using a blocky-type full-body cage:

When using auto-skin transfer with this particular accessory and character combination, this can cause unexpected skinning because portions of this beard accessory model is close in proximity to the cage's upper-chest geometry causing parts of the beard to auto-skin to the chest area instead of the chin:

To prevent the beard from using skinning data from the upper chest, you can remove parts of the cage that the face accessory isn't designed to be skinned to. In the following example, the cage is modified so that it only includes the head geometry:

When automatically transferring skinning data, this beard and partial cage correctly transfers skinning only from the head geometry:

Exporting

Export your model when ready to test your accessory model in Studio or when setting up for final export. When exporting face accessories, keep in mind the following guidelines:

  • Ensure that the final accessory model follows Studio's Modeling Requirements, including properly named mesh and cage objects.
  • Do not export any unnecessary data, such as animation data, or light and camera objects.
  • If exporting PBR textures, follow texture modeling requirements when exporting texture images from your texture software.

To export:

  1. Ensure only the accessory mesh, armature object and cages meshes are exported. Delete all other objects in the workspace.

    1. You can quickly filter out Geo and Att named objects in your workspace to quickly delete them.

  2. Follow Studio's Export Requirements for Blender and save the file to your preferred location. The final export of the eyebrow .fbx is available for reference.

Testing in Studio

To bring your exported model into Studio, follow the instructions in Converting Models to Accessories to import the mesh and convert it to an Accessory. At this point, you can equip the accessory to a humanoid character. If you intend to transfer skinning data from your character to the accessory model, you can enable auto-skinning for your accessory.

Enabling Auto-Skin Transfer

After following the instructions in Converting Models to Accessories to create an Accessory model, you can enable auto-skin transfer to your accessory to transfer skinning data from your character to the equipped accessory.

Use the following steps to set your accessory to transfer skinning data from whichever character model it is equipped to:

  1. In the Explorer, locate the Accessory's WrapLayer instance.
  2. In the Properties, set AutoSkin to your preferred skinning behavior:
    • Disabled: Does not apply Automatic Skin Transfer. This is the default setting.
    • EnabledOverride: Overrides any existing skinning data on the mesh with the transferred skin data.
    • EnabledPreserve: Only transfers skinning data if no skinning data is included with the accessory. Choose this option if you want Studio to only apply the skin-transfer to accessories without skinning data.