Enlarge Image Oculus

I've just walked half a mile up a mountain in the snow, but that's not what's taken my breath away. That honour belongs to Quill, a new virtual-reality tool from Oculus that allows you to paint in the air around you simply by waving your hands.

It's one of many cool and clever virtual-reality developments here at the 2016 Sundance Film Festival in Park City, Utah. VR has exploded in popularity since Oculus, the company that kicked off the current wave of interest in VR with its Rift headset back in 2012, announced its content creation arm Oculus Story Studio at last year's festival.

This year, VR devices are finally on sale, and panels on the embryonic field of immersive filmmaking are packed with interested cinephiles while festival-goers don HTC Vive and Samsung Gear VR headsets to see what the fuss is about. "It's the next step of cinema," said Edward Saatchi, a producer at Oculus.

At the festival's New Frontier Gateway -- where film fans try a host of virtual-reality demos from live action documentaries to computer-animated sci-fi adventure games -- I looked at the map to see that the house where the Oculus team was holed up was a mere half mile away. No problem, I thought... forgetting that it's snowing, I'm wearing totally the wrong shoes, and I have the cardio capacity of, well, a technology journalist halfway up a mountain.

But the hike up what turned out to be a pretty substantial incline was well worth it. By the warming fireplace of the Oculus-occupied house, I'm introduced to Wesley Allsbrook, comic book artist, illustrator and art director of "Dear Angelica". In a cosy media room, I slipped on an Oculus headset and watched a few moments from "Dear Angelica", the third film from Oculus Story Studio following "Lost" and "Henry".

The animated story about a young girl imagining her mother, an actress, unfolds with brushstrokes arcing gracefully through the air, building into a beautiful multi-coloured three-dimensional dragon. You can move around and even through the bubble of luminous lines and swirls, watching the dragon curve around you to envelop you in an ethereal cloud of colour as you turn, move and look around within it.

Enlarge Image Video screenshot by Leslie Katz/CNET

As the lines and shapes form around you, you can reveal different elements by walking around within the virtual space, adding a feeling that you control the pace.

"With Quill, I get to make a mark directly in space," Wesley told me. "I can make my world around me, instead of making a drawing."

She donned the headset to show me how she created the story using a new piece of software developed by Oculus called Quill, painting in the air using Oculus Touch wireless hand controls. You draw a line in the air using the triggers on the controller in your right hand, using the controller in your left hand to rotate your 3D drawing. You can then erase a stroke by clicking on it with another button, or change the thickness of the line with a thumbstick. You can draw brushstrokes that stay solid, or trace out lines that become translucent as you move around them.

Then I got to try it.

Wesley had already sketched a 3D shape of a fish in the air, like a sort of painted wireframe. I started trying to colour it in with simple strokes.

I've always loved to draw, and I've always been fascinated by the possibilities of digital art. I remember creating art in Microsoft Paint by tortuously filling in individual pixels. I remember when I first scanned a drawing and was able to digitally colour and manipulate what I had hand-drawn. I remember the joy of discovering layers in Photoshop. Mind-blowing moments all -- and as hard as I tried to maintain my journalistic composure under that Rift headset, this took me back to those moments of pure creative joy.

At first, I found myself drawing on a flat plane in front of me, as if drawing on a wall. I even stepped from side to side to draw on different parts until Wesley encouraged me to rotate the artwork instead. And as I spun the fish in the air, something amazing happened: I started to draw in 3D.

When I pressed the trigger and extended my arm, the line stretched out away from me instead of staying on the flat plane we're used to writing and drawing on. When I turned my wrist as I drew, the brushstroke corkscrewed through the air. When I spun my hand in circles as I reached out my arm, the brushstroke formed an elegant spiral like those ribbons gymnasts twirl around. The spiraling ribbon-like brushstroke hung in the air in front of me, suspended in space as I moved towards it, around it, through it. I couldn't stop grinning.

I know, I know -- it's hard to describe the experience of virtual reality. The only way to understand it is to try it yourself. And after a long three days of VR movies and animations, I'd started to become a little inured to VR.

But being able to create shapes and brushstrokes in space like this, in an environment Oculus compared to a lucid dream, was exhilarating. The folks at Oculus describe Quill as a tool designed specifically to create this kind of 3D VR experience, as opposed to adapting tools that are used in other media, like the movie cameras or the Unreal gaming engine used to create many other VR movies and animations. Interestingly enough it began life as a project knocked together in a hackathon by Oculus engineer Inigo Quilez after he was disgruntled with traditional VR creation tools.

"Dear Angelica" and Quill will be showcased Tueday night at Sundance when Oculus throws a special event with actor Joseph Gordon-Levitt. Gordon-Levitt got excited about VR when his recent film "The Walk" was turned into a dizzying VR experience that allowed you to tightrope walk high above New York's streets.

Quill is similar to Tilt Brush, a 3D VR drawing experience developed by design studio Skillman & Hackett for the Rift headset, which offers a range of different brushstrokes and effects. At the moment, Quill is an internal tool for story creation with no plans for wider release. The idea is to show a new kind of VR experience to add to the live action and animated forms we're already seeing. But Oculus talks a lot about sharing its knowledge with other filmmakers. "Oculus Studios was created," said Saatchi, "with the goal of taking the members of that community that want something completely new, showing them the movies to inspire them and giving them the tools to make movies themselves."

"We want peers," said Max Planck, technical director of Oculus Story Studio. "We want to be inspired back. Any good filmmaker is inspired by other filmmakers."