Game Level Authoring in XR

Ayaskant Panigrahi

Introduction

Gaming remains one of the primary consumer use cases for Extended Reality (XR). Many popular games offer level editors that empower players to create customized levels, limited only by their imagination. However, exceptional games take it a step further, providing tools that enable players to create content with the same level of creativity and complexity as those designed by the developers themselves. These games often also facilitate easy sharing of user-generated content (UGC). By incorporating a level editor, developers can tap into the collective creativity and ingenuity of their players, and potentially extend the game’s lifespan beyond the support capabilities of the development team. In this article, I will delve into several XR games that feature level editors and highlight key takeaways from their approaches.

Deep Dives into XR apps

Cubism VR

My interest in searching for and creating my own level editors for XR games started with the critically acclaimed and popular block puzzle game, Cubism. Reminiscent of wooden block puzzles and Tetris, Cubism VR challenges the player to fit floating puzzle pieces together to completely fill a target volume. The game’s developer, Thomas Van Bouwel, opened the game to modding by supporting a puzzle file format that could be sideloaded to play new levels. Since the game initially lacked a built-in level editor when I first discovered it, I developed a simple puzzle editing program in Unity that could load, edit, and save puzzles in this format. A subsequent update added an official level editor to the game. The core features that stand out in the official in-game editor experience for this game are:

1. The editor offers the flexibility to create any type of puzzle imaginable, not just edit existing ones. In fact, the developer mentions in the accompanying video that he used a version of the editor to create all the puzzles in the game, ensuring full feature parity.
2. It has an approachable and familiar UI that guides the player through all the steps for creating a puzzle. Players who have completed even a few levels can easily understand how the editor works.
3. Being able to playtest while creating the level is a big win, as it allows the designer to make adjustments and iterate quickly.

Gadgeteer

Gadgeteer is a physics-based VR puzzle game that lets players build intricate Rube Goldberg machines. The puzzle mode challenges the player to create a path from start to finish using limited pieces. The sandbox / maker mode on the other hand lifts this limitation, providing the player with an infinite number of pieces to create complex machines. Some notable aspects of the editor mode include:

1. The editor features a simple and intuitive toolset, reminiscent of SteamVR Home, with only four tools: Create, Clone, Paint, and Destroy. This limited toolset and the intuitive workbench metaphor makes the editor easy to learn and use.
2. Limited snapping functionality and ability to use tools only one-handedly make editing tedious and tiring. This highlights the difficulty of precise manipulation of virtual objects in the absence of scaffolding mechanisms like snapping. It also brings to light controller fatigue issues specific to XR.
3. The sandbox mode is a major draw for the game, and the developers wisely prioritized it as a core feature from the outset. By listening to player feedback and focusing on the implementation of XR interactions that enhance the editing experience, the developers demonstrate a key strategy for success in XR game development. This approach is particularly important, as the medium is still evolving, and comfort and support options are still being refined.

Jumpy Balls

Jumpy Balls is a physics platformer game developed by Mozilla, where the player guides balls towards a target area using various kinds of platforms. It was created as a proof-of-concept for WebXR and ecsy, an Entity-Component-System library. While adding an AR passthrough mode to the now-archived game, I discovered that the game has a hidden level editor mode that can be accessed by appending “?edit” to the URL. Additionally, a complementary hidden feature allows users to export levels to JSON, which can then be added to the game’s level data. However, this editor mode has limitations, as it does not permit the addition or removal of elements within a level. One workaround is to anticipate all required elements ahead of time and manually add them into the JSON before entering the edit mode.

think outside with boxes

think outside with boxes is a WebXR puzzle game based on perspectives and projections. I developed this as a submission to the VR Challenge #2 by Steampunk Digital. From the outset, I decided that regardless of the game I created for this game jam, I would also develop a level editor for it. The spatial nature of the game lent itself well to editing in XR, so I created a full-fledged editor and used it to design the levels. Through this process, I made some key discoveries:

1. Having the level editor (and the entire game) work in both 2D and XR made design and iteration times much faster than if it were solely available in only XR. However, I found that simply mapping interactions from 2D to 3D (or vice versa) in a one-to-one manner didn’t work well. Each environment has its own unique affordances and user expectations, built up over years, which can negatively impact UX if not taken into account. Experimentation was necessary to find what works best for XR.
2. The instant playtest button also proved to be a huge time-saver when designing puzzles.

Rec Room

Rec Room is a popular social VR app themed like a college campus, where each user has a personal dorm room that can be customized over time with unlockables. The app features an in-game tool called the Maker Pen, which enables players to bring their imagination to life, including creating mini-games using node-based scripting features called Circuits. Key takeaways include:

1. Rec Room is available on lots of platforms outside of XR, from phones to consoles and PC. Designing interactions that work consistently and intuitively across all of these platforms and user groups is challenging. What might feel like an acceptable amount of typing and menu hierarchy depth on PC, for instance, might feel like too much in VR.
2. Rec Room’s in-game tool can feel limiting in comparison to VRChat, which provides a Unity SDK to build worlds.
3. Some creators have expressed dissatisfaction with the new UI for accessing these tools, citing that previously easily accessible options are now buried within multiple layers of menus. It is possible these comments are from a vocal minority habituated to their workflow. Still, this highlights the importance of focused testing with expert users who create quality content (vs. the entire user pool), as well as the cost of relearning.

Special Non-XR Mentions

• Any article discussing authorship and editing in 3D would be remiss in not mentioning the creature editor in Spore. The creature editor offers vast creative possibilities, allowing users to build creatures of various sizes and shapes, all while maintaining an intuitive and user-friendly interface.
• Games like Mekorama (which had a version for Google Daydream) and more recently, The Legend of Zelda: Tears of the Kingdom (Switch 2 version), feature the ability to share custom creations with other players using QR Codes. When implemented effectively, this feature can significantly enhance UGC shareability and virality. Moreover, with a dedicated community, it can even outlast any official servers hosting user-created content.

Key Takeaways and Conclusion

As we conclude our exploration of game level authoring in XR, several key points emerge as crucial considerations for developers aiming to create effective and engaging level editing experiences. These takeaways highlight the importance of intuitive design, flexibility, and user empowerment in XR level authoring tools.

• The implementation of intuitive controls is vital. This includes the use of hand gestures, hand-anchored UI, and controller buttons that allow users to seamlessly switch between different modes. Such interfaces not only enhance the overall user experience but also facilitate a more natural and immersive interaction with the level editor.
• The ability to make easily reversible edits is paramount. This can be achieved through the incorporation of a robust versioning or checkpointing system, which enables users to experiment with different designs without the fear of losing their work. By providing a safety net for creativity, developers can encourage users to push the boundaries of what is possible within the game.
• Finding the right balance of complexity in the tools is essential. The level editor should offer enough flexibility to cater to diverse creative visions while remaining accessible and easy to use. Striking this balance is critical, as tools that are too simplistic may limit creativity, while those that are too complex may intimidate users.
• It is crucial that the levels created through the editor match the creativity and complexity of those found in the main game. If the editor’s capabilities are perceived as inferior, players may feel underpowered and restricted, leading to a disappointing experience. By ensuring that the editor’s potential is on par with the game’s design, developers can empower users to create content that is both challenging and engaging.
• Developers can greatly benefit from using the level editor themselves during the game development process, a practice often referred to as “dogfooding.” This approach allows developers to identify potential issues, refine the editor’s functionality, and ensure that it meets the needs of its intended users.
• The ability to easily share creations is a vital aspect of any level editor. By incorporating features that facilitate the sharing of user-generated content, developers can foster a sense of community and encourage users to showcase their creations. This, in turn, can lead to increased user engagement, a broader range of creative content, and a more vibrant community surrounding the game.
  In summary, the key to successful game level authoring in XR lies in creating an intuitive, flexible, and user-friendly experience that empowers creators to bring their visions to life. By prioritizing these elements and incorporating them into the level editor’s design, developers can unlock the full potential of XR game development and provide users with a truly immersive and creative experience.