VR Quick Tip: Reticle Positions

Our VR game, Bazaar, is releasing for the Gear VR in time for Black Friday 2015.

While developing Bazaar, we ran into issues debugging the reticle position -- the eye-shaped cursor in the center of the view that shows where the player is looking. Here’s a quick tip that helped us.

Reticles in VR are tricky because they need to be positioned on their target. Unlike normal games, where the reticle can be drawn in 2D on the screen, VR games need it drawn at a 3D position. To do this, 3D reticles are normally drawn with z-reading turned off and with the reticle scaled to be a consistent size on the screen. This helps you see distance with stereo vision. This might not seem too important, but it’s immediately obvious if the game isn’t doing this. It feels like the reticle is making you cross-eyed.

With stereo vision you see the reticle on the cloud, not the statue’s face.

To speed development, we rely heavily on monitors to show what would happen with a VR headset. But with computer monitors, the reticle always draws on the same pixels in the screen. This means we can’t see the problems with the reticle position. The VR headset is required to spot reticle position issues -- even then sometimes it’s hard to tell exactly where the reticle is drawing when it’s wrong. In these cases, it helps to close one eye at a time to try and figure out its location.

In VR, will the reticle be on the cloud or statue’s nose in this monitor screenshot? You can’t tell!

For quick and easy reticle debugging, my simple trick is to draw a red cube on top of the reticle. This makes it easy to see the reticle position on a monitor and fix all the errors.

So there you have it. My quick trick for fixing reticle problems on a monitor. Shameless plug - if you have a Gear VR be sure to check out Bazaar!