Locomotion 🚂

You know what’s really fun? Being able to move around and interact in a virtual environment. You know what isn’t? Barfing all over your new all birds.

That’s exactly what’s at stake when designing a good VR experience. Particular one that includes movement. When developing for VR it’s important to build a good understanding of “simulator sickness” and what can be done to eliminate, or at the very least, minimise it.

Just like with other forms of motion sickness, simulator sickness affects different people in different ways. As it’s still early days of mainstream VR, there’s still a lot of research to be done into causes and solutions. Having said that there’s also a lot of good material out there that can help you provide comfortable experience for users.

Some general rules of thumb to follow include:

  1. Tightly control the users speed and rate of acceleration. Slower speeds are generally more comfortable for users, as is a very high rate of acceleration. Any gradual acceleration at all in VR can trigger simulator sickness so it’s best to keep speed transitions short and infrequent
  2. Leave your user in control of their vision. In other words don’t disconnect what you see from the users head tracking. If you need the user to look in a certain direction use other techniques such as sound or lighting to draw their gaze.
  3. Make sure your experience is performant by maintaining a suitable frame rate. 90 FPS is optimal.

The best way to stay on top user comfort is to test things on them as early into development as possible. Ask them questions about their comfort levels and always make sure you let them know to remove the headset right away if they feel any discomfort. After all, The last thing you want is to push a tester to the point of ruining their shoes.

VR and the power of scale 💡

One of the most powerful things about VR is its ability to have a shared experience at scale.

From an education perspective this is an extremely exciting thing. The below TED talk is a fantastic example of how VR can bring multi million dollar facilities to every student without the cost of traditional real world labs.

Not only that but the evidence in the video suggests that combining teachers and VR in this way results in a 2x improvement in learning outcomes. Just awesome!


Process: User experience testing 🔬

As I said in my previous post on process, it’s important to test your work early and often. This means getting in front of your users and collecting feedback, aka UX testing.

When you’re starting out with user testing it can be quite intimidating, but with a few tips and a bit of preparation it can be very valuable. There’s a few basic things to consider when carrying out tests.

Asking the right questions

Just rolling up to your user and asking questions may provide some value, but it may also give you some bias or low value results. To avoid this it pays to prepare your questions in advance of the interview. When formulating the questions themselves make sure you avoid both leading and dead end questions.

Leading questions

An example of a leading question is “do you find the mood of the scene magical?”. By asking a question in this way you’re influencing your user to think of the scene in a magical context. This may effect their answers, reducing the value of the feedback. A better question to ask would be “can you describe the mood of the scene?”. It’s more open ended, leaving the user to describe the mood without bias.

Dead end questions

Likewise asking dead end questions also provides little value. Dead end questions are questions that can be answered with a simple yes or no. An example would be “did you enjoy the experience?”. A better option would be “tell me about the experience?”.

If need be, you can always ask follow up questions to clarify anything you feel isn’t clearly communicated in the users answers.

Sample size

On the surface you’d think you’d need dozens and dozens of users to test on, and in the past many UX practitioners have done just that. As it turns out, that really isn’t needed. In fact according to a study by the Norman Nelson Group you’re actually wasting your time with big sample sizes. You’re actually far better served by performing multiple small test on 3-5 people. Not only is it cheaper and easier to do, but it’s actually more effective.

Working with GameObjects in Unity 👾

Given I’m currently learning to develop in Unity I thought I’d share a few tips I pick up along the way to becoming proficient with it.

When creating a scene in Unity you’ll work with loads of different GameObjects. Your virtual world is built out of them (Floors, walls, trees everything) and you’ll be manipulating them all the time.

One thing you’ll notice is the more GameObjects you have the more complex it becomes placing things correctly. Trying to line everything up, preventing different objects overlapping, and just generally making things look as they should, can consume a lot of time.

Thankfully there’s a few things you can do to make life a while lot simpler. First is learning to navigate around the environment, second duplicating objects, third vertex snapping.

Navigating the environment

The odds are good if you’re doing VR development in Unity you’ve played at least some 3D person shooter on a PC or Console. If so, you’re in luck because navigating in a 3D unity scene can be exactly like this with a few extras. Click and hold the right mouse button and you’ll be able to look around the environment with your mouse and use the WASD keys to move forward (W), backward (S), strafe left (A), and right (D). A little extra something for moving quickly is selecting a GameObject and pressing the F key to jump to it for manipulation.

Duplicating objects

When creating an environment it’s essential to duplicate GameObjects or groups of objects. To do this is very easy, just select the GameObject and do what you’d do to duplicate and just like text in a text editor, copy and paste. Easy as that you’ll have a duplicate item to move around and position in the scene.

Vertex snapping

For the first few months I was learning I didn’t know about this one and boy does it save some time and frustration. Let’s say you’ve got a section of wall and you’ve duplicated it to make the wall bigger. You move your newly duplicated wall GameObject to line it up with the original and you slide it along just a little, you eye ball it and there’s a small gap. You move it back a little and now it overlaps. This sort of thing can go on and on. Vertex snapping will save you from hours of repetition by allowing you to snap two objects together cleanly.

To do this, select the move tool then select the GameObject you want to move. Now hold down the V key, move your cursor to a vertex, then click and drag it to the vertex of the GameObject you want to snap to. Now release the mouse button and boom, just like that you’ll have a perfectly placed GameObject in line with the first.

Now to be completely honest it can be difficult to get your head around vertex snapping from reading a text description of it. Thankfully a number of people have made excellent YouTube videos showing just how it’s done. Here’s one I found useful:

For more information on vertex snapping and a whole lot more, see the Positioning GameObjects section of the Unity manual.