Abstract — In this text, we explore the capabilities of the AR Foundation and its implementation through a coded approach for creating video games in Augmented Reality (AR). The rising popularity of visual scripting in game development offers a seemingly user-friendly interface for creators; however, it often comes at the cost of producing redundant or inefficient code, which can be particularly detrimental in the resource- constrained environment of mobile devices. By forgoing visual scripting in favor of direct coding, we propose a pathway not only to avoid these pitfalls but also to harness the full potential of AR development. This approach seeks to streamline the development process during the timeframe of a game jam, highlighting the challenges and triumphs of surviving 48 hours of AR game development without relying on visual scripting.

Keywords—AR, Unity, AR Foundation, Code, GameJam , Visual Scripting

I. INTRODUCTION

In recent years, the video game industry has experienced rapid evolution driven by technological advances such as virtual reality and improvements in graphics. This evolution poses challenges to staying current, as developers must constantly adapt to deliver innovative and engaging experiences that make the most of new technologies, preventing their products from becoming obsolete.

Augmented Reality (AR) represents an enhanced and engaging version of the real world, by integrating with visual elements, sounds and sensory stimuli through holographic technology. AR offers a fusion between the digital and physical world, real-time interactions, as well as precise 3D identification of virtual and real objects.[1]

AR integration has been used in various games in recent years, but its popularity increased significantly with the release of Pokémon GO, developed by Niantic in collaboration with Gamefreak, becoming one of the most popular games of the last decade. This game transformed the perception of the industry, laying global foundations that could drive new AR projects, whether through smartphones or devices such as glasses. [2]

II. EXAMPLES OF VIDEO GAMES DEVELOPED WITH AR FOUNDATION

AR Foundation and Unity helped increment the number of games that combine augmented reality with immersive gaming experiences. Within the most known AR video games are:

Pokémon GO : This game allows players to catch Pokémon in the real world using AR. Developed in Unity, it uses ARCore on Android and ARKit on iOS.

Harry Potter : Wizards Unite : Players explore the magical world of Harry Potter in real life, discovering creatures and artifacts using AR. Developed in Unity, it uses AR Foundation to support a variety of devices.

Minecraft Earth : Inspired by Minecraft, this game allows players to build in the real world using AR. Developed in Unity, uses ARCore and ARKit .

Jurassic World Alive : Players hunt dinosaurs in the real world using AR. Developed in Unity, uses ARKit and ARCore .

The Walking Dead : Our World : Players fight zombies in the real world using AR. Developed in Unity, uses ARCore and ARKit .

III. AR FOUNDATION: FUNDAMENTALS AND FEATURES Unity's AR Foundation is a cross-platform framework

designed for developing augmented reality experiences. It allows creators to design and develop their AR apps once and then build them for Android or iOS devices without any additional settings. This functionality ensures a smooth and efficient transition between platforms, making it easy for developers to maximize their reach with minimal adaptation efforts.

A. Main features of AR Foundation.

• Session

o Enables, disables and configures augmented reality on the target platform.

• Device Tracking

o Monitors the position and rotation of the device in physical space.

• Camera

o Renders images captured by the device's camera and estimates ambient lighting.

• Plane Detection

o Detects and monitors flat surfaces.

• Image Tracking

o Detects and tracks 2D images.

• Object Tracking

o Detect and track 3D objects.

• Body Tracking

o Detects and tracks human bodies.

• Face Tracking

o Detects and tracks human faces.

•

Plane detection

Yes

Yes

Yes

Yes

Yes

Image tracking

Yes

Yes

Yes

Object tracking

Yes

Face tracking

Yes

Yes

Body tracking

Yes

Point clouds

Yes

Yes

Raycasts

Yes

Yes

Yes

Yes

Anchors

Yes

Yes

Yes

Yes

Yes

Meshing

Yes

Yes

Yes

Environment probes

Yes

Yes

Occlusion

Yes

Yes

Participants

Yes

Point Clouds

o Detect and track key points in the environment.

• Raycast

o Cast rays at detected objects to interact with them.

• Anchors

o Allows you to fix arbitrary points in space that remain constant.

• Meshing

o Generates meshes of the environment for a detailed representation of it.

• Environment Probes

o Create cubemaps to reflect the surrounding environment.

• Occlusion

o Allows you to hide augmented reality content behind physical objects and performs human segmentation.

• Participants

o Monitor other devices in shared AR sessions.

[3]

The AR Foundation package acts as a set of interfaces for augmented reality functionality, without directly implementing any features. To use AR Foundation on a specific platform, it is necessary to additionally install a plugin package provided by the manufacturer of that platform. Unity offers official support for the following vendor plugins:

• Google ARCore XR Plugin for Android.

• Apple ARKit XR Plugin for iOS.

• Apple VisionOS XR Plugin for VisionOS.

• OpenXR Plugin for HoloLens 2.

• Unity OpenXR : Meta for Meta Quest.

These plugins enable the implementation of AR Foundation capabilities on their respective platforms, allowing developers to create cross-platform augmented reality applications with a common code base. [4]

Figure 1 outlines the key features of leading augmented reality platforms, including ARCore, ARKit, and OpenXR, among others. It serves as a vital tool for developers to assess the level of interactivity and specific functionalities each platform offers for their AR projects. By referring to this table, developers can make informed choices about the most suitable technologies for achieving their design goals, thereby enhancing the end-user experience across various devices.

Fig. 1. Comparative Overview of Augmented Reality Platform Features

Drawing upon the insights and data from [5] [6] [7] [4]

[8] [9] we constructed Figure 2, which offers a comprehensive comparison of key features across various augmented reality development platforms and tools, including AR Foundation, ARKit/ARCore, Vuforia, RealityKit, and Unreal Engine. This analysis encompasses factors such as multi-platform compatibility, image/object recognition capabilities, user-friendliness, cost implications, integration ease with Unity, device support range, availability of location-based AR features, graphical fidelity, and access to the latest technological advancements. The table can be used as a guide for developers to evaluate and select the most suitable AR development tool or platform that aligns with their project requirements and goals.

B.

Criterion

AR

Foundati on

ARKit

/ ARCo

re

Vuforia

Reality Kit

Unre al Engi ne

Compatibil ity Multi platform

Yes

No

Yes

No

Yes

Image /

Limited

Yes

Excellent

Limited

Limite

Object

d

Recognitio

n

Features Advanced

Yes

Yes

Yes

Yes

Yes

Easy to use

high

high

Half

high

Half

Comparison to other AR development platforms

Features	ARCore	ARKit		OpenXR
Features	Android	IOS	VisionOS	HoloLens	Goal Quest
Session	Yes	Yes	Yes	Yes	Yes
Device tracking	Yes	Yes	Yes	Yes	Yes
Camera	Yes	Yes			Yes

Cost

Free

Free

Subscripti on / Lic .

Free

Free / Varies

Integration with Unity

Narrow

N/A

Good

Narrow

Good

Support for a Wide Range of Devices

Yes

Limited

Yes

Limited

Limite d

Location- Based AR Features

No

No

Yes

No

No

High Fidelity Graphics

No

No

No

Yes

Yes

Access to Latest Features

Depends on Unity

Yes

Depends on license

Yes

Yes

Fig. 2. Comparative Analysis of Augmented Reality Development Platforms and Tools

By synthesizing the information from both Figure 1 and 2, we gained a comprehensive understanding of various AR platforms and tools available. After careful consideration, we ultimately decided to utilize AR Foundation in conjunction with Unity due to the numerous benefits it offers. However, one drawback we encountered was that most tutorials for AR Foundation were geared towards utilizing visual scripting, which wasn't our preferred method. Despite this challenge, we recognized the potential of AR Foundation and Unity to meet our project requirements, leveraging their advanced features and multi-platform compatibility to create immersive AR experiences.

IV. UNITY: VIDEO GAME DEVELOPMENT PLATFORM Unity is a highly used game development platform that

offers a wide variety of tools to create interactive experiences in 2D, 3D, and virtual and augmented reality (AR). It is known for its flexibility, ease of use, and its ability to create cross- platform games. Unity provides an intuitive editor that allows developers to design environments, create animations, program behaviors, and deploy their games on a variety of platforms, including PC, consoles, mobile devices, and the web . [10]

A. Advantages of using Unity for AR game development

Unity stands as a top choice for crafting AR games, thanks to its user-friendly nature and broad compatibility. With Unity, developers can effortlessly target various devices, spanning iOS and Android platforms, making their AR creations accessible to a wide audience. This versatility streamlines development, letting creators focus on crafting immersive experiences without fretting over compatibility issues. Plus, Unity's intuitive interface and extensive documentation make it easy for developers of all levels to dive into AR game development, regardless of their experience.

Moreover, Unity's vibrant community and strong graphics support add to its appeal. With a bustling ecosystem of developers and a treasure trove of tutorials, forums, and assets, Unity fosters collaboration and accelerates development. This community-driven approach encourages innovation, helping developers turn their AR gaming dreams into reality. Additionally, Unity's powerful graphics tools empower creators to build visually stunning AR environments that grab players' attention. And with AR Foundation seamlessly integrated into Unity, developers can create AR apps with ease, ensuring smooth performance across different devices. Overall, Unity's blend of accessibility, community support, graphics prowess, and AR Foundation integration makes it a go-to platform for captivating crafting AR gaming experiences.

V. VIDEO GAME DEVELOPMENT WITH AR FOUNDATION

A. Basic steps to start developing an AR game with AR Foundation.

B. Description of personal experience as an AR game developer using AR Foundation.

During the Global Game Jam, the team embarked on the challenge of creating an augmented reality (AR) game using the AR Foundation, motivated by the event's theme: "Make Me Laugh." With the aim of creating a fun and novel experience, we created a game titled "Ayudando Ando". [11]

C. Challenges faced during the development process.

During the 48 hours of the event, our team faced a series of challenges both technical and creative. We started by diving into the tutorials provided by Unity with the goal of mastering the generation of objects in markers through the use of the Image Track Manager. This initial step was

crucial, as it allowed us to instantiate prefabs (A prefab is a pre- made object or group of objects in Unity that can be reused across different parts of a game. It simplifies development by allowing quick and easy placement of game elements) within the real environment, thus establishing a solid foundation upon which we could build interactive levels and immerse players in a unique and immersive gaming experience.

Fig. 3. AR solution in Visual Scripting

Despite the advantages of visual scripting, we soon ran into limitations in implementing additional functionality. Block programming was restrictive, and the lack of tutorials focused on direct coding prompted us to look for alternatives.

Our research led us to delve into the official documentation and follow specialized content creators, where we finally discovered that instead of the AR-specific ARRaycast, what we really needed was to use the traditional Unity raycast.

Fig. 4. Proposed solution for object detection in code

With the right code, we achieve seamless interaction with objects instantiated in the real world. This advancement meant a big step forward in our project, allowing us to continue development with a new perspective and tools.

alternative solutions are critical when working with emerging technologies like AR Foundation.

Additionally, we emphasize the importance of extensive planning and research before embarking on a project of this nature. A good understanding of the fundamental principles of augmented reality (a combination of digital and physical worlds, interactions performed in real time, and precise 3D identification of virtual and real objects [1]) and how AR Foundation works can greatly facilitate the development process and reduce the likelihood of facing significant technical obstacles.

VI. CHALLENGES AND FUTURE OF AR VIDEO GAME DEVELOPMENT

As a team, we're constantly seeking out new tutorials, guides, and best practices to enhance our skills and expand our knowledge base in augmented reality. This proactive approach ensures that we're well-equipped to face the challenges and opportunities that come our way, including the integration of cutting-edge technologies like the Apple’s Vision Pro. We excitedly anticipate the integration of AR Foundation with Vision Pro, as it promises to open up exciting possibilities for learning and potentially creating even more immersive games that push the boundaries of what's possible in augmented reality.

VII. CONCLUSIONS

The development of augmented reality (AR) games with Unity's AR Foundation marks an exciting milestone in interactive entertainment, merging the digital and physical worlds through technology and creativity. Despite the technical challenges and the quest for innovation, it offers enormous possibilities to transform our interactions with technology. However, it faces a shortage of documentation and pure code examples; most tutorials lean towards visual scripting, which can be an obstacle for those who prefer direct development in code. This aspect underlines the importance of expanding resources for a more technical implementation, allowing developers to fully exploit the potential of AR Foundation.

ACKNOWLEDGMENT

We would like to thank the REDINDVJ for the publication opportunity, as well as the IIDIV and 48 to play for the support during our participation in the Global Game Jam.

VIII. REFERENCES

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] Reality Experiences,” Unreal Engine, 2024. [Online].

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[1 Unity, “Unity Documentation,” 2024. [Online].

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https://globalgamejam.org/games/2024/ayudando-ando-

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