Distances in VR
From building 3D scenes to designing object interactions, depth and distance are an essential part of VR design. It’s also a delicate balancing act – between our natural instincts about the physical world, and the unique capabilities of the hardware.
Safety Goggles: 10 centimeters (4 inches). As human beings, we’ve evolved very strong fear responses to protect ourselves from objects flying at our eyes. Objects should never get too close to the viewer’s eyes, so you’ll want to create a shield that pushes all moveable objects away from the user. In Unity, for instance, one approach is to set the camera’s near clip plane to be roughly 10 cm out.
Optimal Tracking: 30 centimeters (12 inches). While the Leap Motion Controller can track more than 2 feet away, the “sweet spot” for tracking is roughly 1 foot from the device. This is the best range for reliable user interactions.
Object Rendering: 75 centimeters (30 inches). In the real world, your eyes are able to dynamically adjust depending on how near or far objects are in space. However, with headsets like the Oculus Rift, the user’s eye lenses remain focused at infinity. This means that objects can’t be comfortably rendered at close distances. The most comfortable rendering distance will depend on the optics of the VR headset being used. For example, the Oculus Rift DK2 recommends a minimum range of 75 cm. Since this is beyond the optimal Leap Motion tracking range, you’ll want to make interactive objects appear within reach, or respond to reach within that range.