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Classic design principles to inspire your VR & AR creationsLast updated: January 2019
What you will get from this page: classic design principles to inform design of your XR content. These come from Don Norman, the Founder and Director of the Design Lab at the University of California, San Diego, and co-founder of the Nielsen Norman group.
By seeing how many everyday objects–doors, windows and chairs–are designed for easy use (or not), you can start to understand how to make your virtual content feel natural to players.
You can watch the session by Stella Cannefax, a Unity Labs engineer, here.
How do you know a chair is for sitting, or a ball for throwing? It’s obvious, right? Affordances are the innate properties of a thing which determine how it can be used, or the relationship between the thing and a person. When you look at a chair, you just know that it’s for sitting in a particular position, or that a door is for opening and going through.
But, how do you know if you’re supposed to push or pull the door open? That’s where signifiers come in.
Sometimes the innate properties of an object cannot imply what it affords. Signifiers are signs that make affordances clearer, for example, a sign on a door that reads “pull” or “push”. They try to close the gap between the truth of what an object can do, and our perception of what it can do.
Tips for your XR design: Wherever you can, avoid using signifiers that are text-based, as the text will have to be translated if your game is available globally, plus, on current-gen VR hardware, text can be hard to read at a distance.
Mappings are relationships between two sets of things. In the case of XR, there is the set of possible user actions/input (the total set of things a user can do), and, the possible set of actions afforded by your system or object (the total set of things that we allow to interact in our system or application).
Tips for your XR design: Be aware that often, a mapping will feel natural to you, but in fact it’s a learned experience, rooted in your culture, and therefore might not be universally understood.
Stella gives the example of prototyping a tool that lets you place lights in VR and then modify their range and intensity with only hand motions. She had to think carefully about what hand motions (user input) would most naturally, and universally, map to the system actions, (adjusting range, intensity, and so on)? For example, an upwards hand motion to most people would indicate increasing the intensity of the light.
Feedback communicates the results of a user action. In VR especially, the feedback has to “feel” real so the user remains immersed.
Tips for your XR design:
Feedback has to be:
- Fast: even a 100ms delay is slow for users in a real-world situation. Ensure that your chosen feedback channels relay feedback fast enough.
- Planned: actions need confirmation, but without distracting the user.
- Prioritized: you’ll need to prioritize multiple types of feedback that are important in any given interaction. And, experiment with you to present feedback so that it gets the player’s attention.
Stella points out that feedback on one channel doesn’t necessarily interfere with another type of feedback on another channel. Users can comfortably receive multiple types information through multiple channels. But, multiple kinds of feedback via a single channel can be confusing.
Constraints are limits on the possible user actions in a system.
Tips for your XR design:
Some constraints XR developers have to work within include:
- Maintaining 90 FPS.
- Limitations of specific hardware.
- Head and hands tracking.
Think about how you can use constraints in XR development to enhance the fun and immersion of your content. Here’s a great talk on creative solutions from Owlchemy Labs, who developed a VR game based in the Rick and Morty TV series.