Owlchemy Labs

Falling, flying, and headaches: the physical, and unique, demands of development in virtual reality

Falling, flying, and headaches: the physical, and unique, demands of development in virtual reality

Dejobaan and Owlchemy labs first teamed up to make AaaaaAAaaaAAAaaAAAAaAAAAA!!! for the Awesome, a sort-of sequel to the almost surreally fun AaaaaAAaaaAAAaaAAAAaAAAAA!!! A Reckless Disregard for Gravity. You play the part of a daredevil skydiver who flies through abstract environments, moving close to buildings without hitting them to gain points.

Give the trailer a quick watch so you understand the visuals of the game, this will be important later.

People had begun to ask about Rift support, and when a development kit landed at Owlchemy Labs, they got to work.

“We had our first build up and running on day one. The Oculus crew did a good job of providing sample code and a clear API to work with,” Owlchemy’s Alex Schwartz told the Report. “The skyboxes were completely wrong and messing with our eyes pretty badly, nothing was tuned properly, and our interface was completely incorrect, but it was WORKING! And it was incredible.” Of course, the last 20 percent of a game take 80 percent of the time, and designing for virtual reality is an intense process, and there are few best practices that are widely known.

Getting it right

The first thing Owlchemy realized is that the standard 2D heads-up display is just about worthless in virtual reality.

“It breaks immersion, causes eye focus issues and is blurry at the edges, where you would traditionally put HUD elements. It turns out your periphery is great at sensing motion but not at reading tiny bits of text,” Schwartz said. “We opted to remove all 2D HUD elements while falling in-game, except for occasional informational messages that appear in the middle of your view to let you know it’s time to deploy your parachute. These come up and then quickly fade away. We can get away with this because most information is conveyed to the player via the in-world visual and audio cues.”

The menus were rendered to a flat plane, and then suspended that in front of the player, in the foreground. Text was scaled up, and it expands even the player mouses over elements of the menu, allowing you to read the text. It’s not perfect, and many of the challenges here will be fixed when a high definition version of the hardware is released, but it’s serviceable for getting information to the player and getting them in the game. It’s one of the few full menus available for the Oculus Rift right now that actually works, and other developers will likely be learning from the work and experimentation Owlchemy put into the process.

“In the future when developing games from scratch for VR, developers will need to be inventive when it comes to new ways to represent menu systems, including using head tracking, reducing content, contextualizing data instead of pinning it to the edges, and even using 3D content incorporated into the world,” Schwartz stated.

Looking down, without killing your neck

You fall straight down in the game, but looking straight down at your feet to match the camera angle is hell on your neck. They experimented with just rotating the camera angle 90 degrees, so suddenly looking ahead was like looking down. Imagine the wall in front of you was the ground, and you began to fall towards it. It worked, but it didn’t give them the feeling they were looking for. They don’t want you to feel like Superman flying forward, your body should feel as if you were falling down.

The solution was magic, but it’s hard to explain without putting you in the hardware itself. The camera angle is rotated 45 degrees downward.

“What really happens is quite cool. When we start the level and the player is walking around on the top of a building, their camera angle is matched 1:1 with the real world, but once they jump off, the camera re-orients in a thrilling sensory moment where the player begins their fall,” Schwartz explained.

“It truly feels like you’re weightless and actually hurtling through the air. Those with tangible fears of heights will feel that same uneasiness when looking over the edge of the building, down to the city below. It’s simultaneously thrilling and unbelievable. In that moment, we re-orient the camera downward by 45 degrees, and players feel completely natural starting their descent.”

What’s interesting is that your body thinks you’ll looking straight down, to the point where it can be uncomfortable to remove the Rift. “It’s a bit disorienting to return to the real world,” Schwartz said. “You could have sworn that you were looking right down at your feet, but in fact, you were not. It’s all Hollywood magic.”

The camera angle is sacred.

Another aspect of the game’s design that feels perfectly natural when playing, but came after intense experimentation and trial and error, is how the game handles your view, and movement.

“The player can turn their head and not only do they expect their head to be able to turn, but their eyes, brain, and inner ear also expect that freedom. Conversely, when the camera view rotates without them turning their head, their body is confused by the disconnect,” Schwartz explained.

You can experiment with this effect at home! Get someone into a Rift demo that allows mouse look, have them stare straight ahead, and then adjust their view with the mouse, without warning. It makes the player sick almost immediately. Even when you control the mouse yourself, moving your view without moving your head can be sickening.  

“For that reason, we limited the mouse look in Aaaaaculus! to be heavily smoothed and affect only a single-axis. This allows the player to rotate while looking down, a corkscrew motion, which is useful in the game when you want to face the opposite way,” he said. “Having un-smoothed, full look rotation with the mouse is wild and unexpected when you get used to full Oculus head tracking, so we had to be careful with the other ways that we modified the camera angle, such as hitting a building, shaking the camera when deploying parachute, dying, etc.”

Missing one of these details would make most games hard to control, but in virtual reality you can actively make the player sick or disoriented in all these different aspects of controls and view don’t line up perfectly. In fact, that brings us to…

Developing for the Rift is physically taxing

Most game development happens on a computer screen, or maybe two monitors so you can test your work. You adjust something, and then play the game to see if your solution worked. A bug can be spotted, and then fixed. It’s not easy, but people know how to do it. This isn’t the case in virtual reality.

“The problem comes from switching contexts back and forth from Oculus Rift to the real world, or a computer monitor, which is necessary when making tweaks and fixing bugs,” Schwartz said. “This switching back and forth hundreds of times a day causes strain on your eyes and we found that taking a day off was necessary after an extended stint of development.”

It’s the same way with bugs. Inside the Rift, they can cause anything from eye strain to headaches, effectively killing productivity. One bug causes an incorrect image to be shown to only one eye, while another caused the view to spin wildly. To fix these issues, developers had to spend a significant amount of time viewing them in the Rift, trying to determine if they had been fixed. Imagine having to deal with a bug that could make you physically sick to your stomach all day, and you begin to see how wrong this could feel.

“Building this port was a huge lesson in VR, and it became clear that we as developers have a ton to learn about this space. It’s an exciting time to be developing software for such an unexplored space,” Schwarts told the Report. “It’s very much the Wild Wild West when it comes to VR best practices. We’re happy to help further that along, even if just a bit.”

They sent me an early, unfinished version of the game, and their work is amazing. You truly feel as if you’re falling through these amazing environments, which is a scary, thrilling thing to experience. Your stomach drops to your feet every time you begin falling, and the 45 degree angle of the view works very well; you feel as if you’re staring straight down. This version of the game will be added as a free update to the game in the near future.