All content in this course uses:

Attach and position 3D accessories on a tracked face, optimize meshes and custom assets, then build and test the app.

Add accessories to your filter

When you’re tracking the user’s face, you're also effectively tracking the position and rotation of their head. This allows you to add 3D models on and around the user’s head, like a halo or funny glasses!

In this tutorial you'll do the following: 

Place the 3D accessories, using the Face Reference Mesh as a reference.

Learn about the basics of mesh optimization and working with custom assets.

So far you’ve added a 2D texture to your app, but AR filters can do more. In this tutorial you’ll do the following:

Place the 3D accessories, using the Face Reference Mesh as a reference. 

Learn about the basics of mesh optimization and working with FBX custom assets.

By the end of this tutorial, you’ll be ready to start making your own 3D face filters. 

Overview

The package you downloaded for this project contains pre-made accessories that you can add to your scene. In the 

 and take some time to explore the provided models. 

Explore the 3D accessories

Before you attach one of these 3D accessories to the face tracker, you need to add a visible face reference to your 

Follow the below instructions to add a face reference: 

 prefab in the folder to open the prefab in the 

window to act as a reference. To zoom in on the

  Drag one of the provided accessories onto the 

This will add the accessory to the prefab as a child of the GameObject. 

  Use the Transform tools to place your chosen accessory in the correct position. You can also adjust the rotation and scale if necessary. 

 If you need to refresh your memory, you can 

review the Transform tools and their shortcuts

window, select the back arrow in the top left of the window to exit prefab editing mode.

Attach an accessory to the face tracker

When you build your application now, the accessory you added should appear in the correct position on your face. This may take some trial and error. If you’re not happy with the position of the accessory, open the prefab again to make further adjustments.

Follow the below instructions to build and test your app:

 Make sure that your device is plugged in and then select 

 The application will open automatically on your device. 

When a face is detected, the application should display the accessory you added (though it may not be in the perfect position).

 For a reminder of how to build to your device, you can review the process for 

Build and test

Since AR typically runs on mobile hardware, it’s critical to create and use optimized assets for your applications. Optimization is a complicated topic, and there are many ways to optimize experiences.

 is one of the most important ways you can ensure better performance in your games and apps. The mesh for every model in a game or application (like the accessory that you just added to your AR app) is made up of polygons. The number of polygons in your game assets influences the performance of your game. High polycounts require a lot of real-time calculations and management, leading to a drop in frame rate. 

For mobile hardware, keeping the polycount between 300 and 1500 polygons per mesh will yield good results, whereas for desktop platforms the ideal range is 1500 to 4000 polygons. Keep in mind that these are only general recommendations. The overall polycount in the scene is also critical, meaning a scene with lots of characters would need to use even lower polycount models.

If you want to know more about mesh optimization, you can explore the following resources:

Arm & Unity Presents: 3D Art Optimization for Mobile Applications

, which is an intermediate course for mobile development.

, which you can use to give low-poly models high-poly details.

Tips on using your own assets 

If you create your own assets and export them to Unity in FBX format, the materials and textures are usually embedded in the model during the export process by the modeling application, such as 

.  When you import these models into Unity, the materials and textures will often not be visible and the model will only display in gray.

To fix this, you need to extract the embedded materials and textures after you have imported the model:

 folder and select the imported FBX model.

 and choose the folder where the texture will be saved.

 and choose the folder where the materials will be saved.

Import FBX files

If you want to further develop your skills, explore new concepts, or improve your project, check out some of the optional activities below. Each one is tagged as either Easy or Difficult, so you can choose the level of challenge. 

These activities are entirely optional, so if you’re not interested, no problem — just skip this step. We do recommend attempting at least one of them in order to get the most out of this learning experience. Good luck!

Easy: Import accessories from the Asset Store

The Unity Asset Store has many different kinds of assets you can use in your applications. Remember to use low-poly models for your app to ensure good performance on mobile devices. The 

 from Unity is a great asset package to start with! 

Find low-poly assets in the Unity Asset Store.

Add the accessory model or prefab to your app using the process that you followed earlier in this tutorial.

There are many ways to create your own 3D accessories both inside of Unity and with third-party applications like 

. In Unity, you can use combinations of primitive shapes that share an empty parent, like cubes, spheres, and capsules, to create new looks and objects. You can also use Unity tools like 

 to create more complex shapes inside of the Editor.  

When you’re ready to create your own 3D masterpiece, remember to use the Face Reference Mesh as a reference for the placement, rotation, and scale of your own 3D accessories. 

More things to try

In this tutorial you learned how to add additional 3D accessories to a face filter. In the next tutorial, you'll make things even more exciting with special effects!

Next steps

Absolute Beginner AR Development

Zu-UnityLearn

Desarrollo de AR para novatos

Hammad_N

Games

Develop AR experiences that use trackable targets in the environment

Build AR projects to mobile devices

 Crear proyectos de AR en dispositivos móviles.

robinmitra

Desarrollar experiencias de AR con objetivos que se puedan rastrear en el entorno.

Unity Version 2022.3