Difference between revisions of "Virtual reality"

Revision as of 08:24, 6 November 2015

Virtual reality or VR for short usually refers to stereoscopic 3D real-time rendering.

Art Rules for VR Environments

At Playful we are building a VR game with Oculus. Before we ended up with our current art style we tried a slew of different art styles. I've developed on DK1, HDKit, Chrystal Cove and DK2 ( and others )

The biggest challenges are mipping and aliasing. The screen is just inches from your eyes and each camera alias and mips slightly differently. This causes a lot of discomfort. You also lose a lot of resolution with the camera shader used to send a distorted image through the lens.

(Anti-Alias is the smoothing of polygonal edges. Mipmapping is the smoothing of textures as the angle / distance increase from the render camera.)

These are the rules we came up with so far.

• Use Chromatic Aberration to correct color bleeding from the lenses.
• Don't use high frequency detail or noise in textures. Even with mip mapping enabled it just turns into swimming pixels.
• 3D geometry "feels" way better than normal maps.
• Specularity instantly give a lot of interest in VR.
• We used a lot of angular and organic shapes because vertical and horizontal lines would align to the screen pixels and alias very badly.
• We rendered the final image at 2592x1458 then down scaled to 1920x1080 to get better anti-aliasing.
• In Unity we used the 8x Multi-Sampling. (Along with the upscaling.)
• Skyboxes require a special shader to display the same on both eyes/cameras.
• We are working on a shader that fades out texture detail at a distance to prevent mipping / swimming textures.
• You need to maintain 76 FPS for low persistence to activate on DK2. This is a challenge because everything is rendered twice, once for each eye.

I'm sure I'm forgetting lots of stuff right now. If I remember anything pertinent I'll update.

Image by Playful.

Links

• Oculus Connect: Learning from Lucky's Tale presentation by Design Director Dan Hurd and CEO Paul Bettner from Playful at the Oculus Connect developer conference
• The quest for comfortable VR by Michael Schenck
• Designing for virtual reality by Xin Xin