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Creating custom textures and 3D models for Augmented Faces

To implement Augmented Faces, you need customized textures and models for overlaying on identified face meshes. These assets are created by artists ahead of time in 3D modeling and animation software, and exported as FBX files.

The SDKs ship with a canonical_face_mesh.fbx file and a canonical_face_mesh.psd file to help artists create assets that will overlay properly onto faces detected by ARCore. These files can be found in the following locations for each SDK:

SDK Location
ARCore SDK for Android assets/canonical_face_mesh.fbx
ARCore SDK for iOS assets/canonical_face_mesh.fbx
For iOS, note that both the FBX and PSD files are included in the public iOS GitHub repo, but are not shipped as part of the ARCore Cocoapod.
ARCore SDK for Unity /Assets/GoogleARCore/Examples/AugmentedFaces/Models/

Using the FBX file to create assets

The FBX file contains the face mesh topology, UV texture coordinates, and rig that defines the supported facial regions provided for creating and attaching assets. To ensure they're compatible with ARCore, FBX files should be saved using supported settings. You can then import these files into your project as SFB files.

This file contains a reference facemesh that should not be exported as part of the final FBX. ARCore will generate and update a separate face mesh at runtime.

Using the PSD file to create assets

The .psd face mesh reference texture is used to see how a texture that an artist creates lines up with a user's facial features at runtime. It includes four layers:

  • Mask: Shows where the eyes, nostrils, and mouth are located in the texture.
  • Lines: Guidelines that show how a user's facial features line up with a texture during runtime.
  • UVs: Represents triangulation of the 468 point face texture mesh.
  • Background: A neutral gray background layer to make the other three components visually clear.

If you modify the PSD file, you should see your changes as soon as you export.

FBX asset format and requirements

We recommend and support the following settings for FBX files exported from modeling and animation software.

  • File format: FBX 2016/2017 or later

  • Axis conversion: Up axis is Y

  • Scale factor: Centimeters

  • Required geometry settings:

    • Smoothing groups
    • Smooth mesh
    • Referenced asset content

  • Recommended geometry settings:

    • Tangents and binormals
    • Triangulate
    • NURBS

  • Animation: enabled

  • Deformed models settings:

    • Deformed models
    • Skins

Customizing the canonical face mesh

If models and textures are being created using the assets/canonical_face_mesh.fbx included in the SDK, these settings are also required when exporting FBX files:

  • Make sure the any custom meshes are skinned to the associated bones or regions.

  • Use the following hierarchy:

    asset
|__root
|   |__NOSE_TIP
|   |__FOREHEAD_RIGHT
|   |__FOREHEAD_LEFT
|__facemesh           <-- for reference
|__                   <-- place additional custom 3D meshes here

  • Do not export the included facemesh model. This mesh is for reference only. ARCore will create a separate face mesh at runtime. Use the UVs in facemesh as a reference when creating custom face mesh textures.

  • Place custom meshes as children of the asset node.

  • Use of namespaces is supported.

  • The asset contains four bones consisting of root and NOSE_TIP, FOREHEAD_RIGHT, and FOREHEAD_LEFT regions. Do not change the names of these bones.

Comparing coordinate spaces

Since different content packages work with different coordinate spaces, it is best to check the deltas between your content creation package and the target platform when creating assets. Use the following coordinate axis asset to visualize these differences.

Importing and using the coordinate axis asset

Use the following steps to identify the correct facing axis, up axis, and scale for your setup.

  1. Import the coordinate axis asset into your digital content creation package.

  2. Rotate the object so that the colored arrows and axes line up:

    • Red: X+
    • Green: Y+
    • Blue: Z+

  3. Scale the object so that the cube represents a single unit. If the size appears to be inaccurate in your app, adjust the scale to centimeters. For example, if one unit represents one meter in the scene settings, set Scale X, Scale Y, and Scale Z of the asset by a factor of 0.01.

  4. Export the asset using the OBJ file format.

  5. Import the asset into your project and attach it to a region. Compare the position, size, and orientation of the asset to its expected dimensions.

Exporting assets from the canonical face mesh

When exporting assets from the canonical face mesh, the coordinate spaces may differ depending on your setup and content package. Refer to Comparing coordinate spaces to ensure that the assets are configured with the facing axis, up axis, and scale according to your content package.

A mesh is not required to be skinned to associated bones or regions. However, an unskinned mesh must be a child of the associated bone or region. Local rotation and translation offsets can then be directly applied to child meshes.

The following steps assume that all meshes have been positioned and rotated to your liking, and are ready for export.

  1. Set the facing direction. Apply global rotations to the root joint only, instead of to the child joints or meshes. If the whole asset is facing in the opposite direction, set Up Axis of the root to 180.

  2. Reset the region transforms to the origin. Select the regions NOSE_TIP, FOREHEAD_RIGHT, and FOREHEAD_LEFT. Set the Translate and Rotate values to 0.

  3. Scale the asset correctly. If the size appears off in your app, adjust the scale to be in centimeters. For example, if one unit represents one meter in the scene settings, select the regions NOSE_TIP, FOREHEAD_RIGHT, and factor of 0.01.

  4. Export each region separately. For each region, select all corresponding meshes, then choose Export Selection.