5 secrets to making a virtual reality film

The unsolved murder of teenager Ramona Wilson is the subject of CBC's firstvirtual reality documentaryHighway of Tears.

Wilson's body was found in 1995, nearly a year after she went missing along the notorious stretch of B.C.'s Highway 16 between Prince George and Prince Rupert, where at least 18 women have been killed or have gone missing since 1969, most of them Indigenous. First Nations communities say the number is closer to 50.

The documentary uses virtual reality (VR) to allow viewers to explore a three-dimensional space by simply moving their heads. As a relatively new technology, the rules and conventions for creating VR are still being established. Here are five cool things you probably didn't know about making a VR film.

How to watch

The best way towatch theHighway of Tearsdocumentary andget the full virtual reality experienceis to use anOculus Rift or Gear VRheadset.

You can also view a 360video version of the documentaryon amobile device using theYouTubeappor by visiting theThe Current'sFacebookpage.

Android users can download theCBC VR appin the Google Play store; the iOS app foriPhone usersis here.

1. There is nowhere to hide

VR is shot using as many as 16 GoPro cameras set up to shoot 360 degrees, which means once you hit "record" on the cameras, you have get out of the way. There is no such thing as behind the camera. To shoot this documentary, we found ourselves hiding in ditches, bushes and even closets. We also sent the cameras up in a drone, which we flew far enough away so you couldn't see us.

2. There are no cutaways

Interviewing people becomes more difficult in virtual reality because, unlike conventional documentaries, VR can't employ B-roll (supplemental) footage to mask edits. Once you drop the viewer into an environment, the shot has to be played unedited until you move on to the next shot. We had to put the documentary together in an unconventional way: we first cut the audio from our interview with Ramona's mother, Matilda Wilson, and then laid the images over it.

3. The pain is in the post

VR technology is advancing at a remarkable pace, but the most cumbersome, time-consuming and expensive part of making a VR doc is the post-production. An editor has to stitch together the images shot on multiple GoPro cameras to create one seamless image. This becomes all the more complicated when people move through the space or when the camera itself is moving, such as in the aerial shots of the highway we included in this VR doc.

• How to watch The Current's VR documentary
• Learn more about the Highway of Tears VR documentary
• In virtual and augmented realities, computers adapt to humans

4. Everything is 360

It's not just the visuals in VR that exist in 360 degrees, the sound is also 360. Sound in VR most oftenmirrors the way we actually hear the world. In the Highway of Tears doc, the sound of a car driving past you along the highway will move from behind and to your left, to up ahead and to your right. The crickets in the woods will sound different depending on which direction you are facing.

5. We want your 'presence'

VR is an immersive experience that can trick your brain into believing you exist in a virtual world. The 3D and 360-degree visuals, combined with 360-degree sound, create an almost complete suspension of disbelief that is referred to as a sense of "presence." Presence can create a visceral experience of a story that cannot be emulated with other media. VR is sometimes referred to as an "empathy machine" because of this potential to connect viewers with the content they are viewing.

Josh Bloch is a producer at The Current and one of the producers of Highway of Tears, which launches Monday.

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