Hi everyone! I’m Derek, a gameplay engineer on Overwatch and wanted to run through this new feature in version 1.42, and exactly what it does and how it works.

First, a quick summary on how aiming and shooting happens in Overwatch. Overwatch simulates (or ticks) every 16 milliseconds, or at 62.5Hz. Each tick, we update the players aiming direction based on whatever raw inputs we’ve received from the mouse hardware since the previous tick. If the player has pressed primary fire, we then launch their shot in that direction (assuming they are alive, have ammo, aren’t in the middle of some other action, etc.)

Despite this being a conventional way of handling mouse input in a first-person shooter, we wanted to do better. Many gaming mice these days support 500Hz, 1000Hz or even more in terms of polling rates. At 1000Hz, this means the mouse movement done between game ticks can be done by as many as 16 discrete mouse movements delivered from the hardware. An example here may help.

This is a simulated flick in Overwatch. By simulated I mean uniform mouse movement per mouse polling frame, which isn’t how humans move a mouse, but is helpful for purposes of explanation.

From above, here’s what it looks like:

The white lines are where the player’s aim direction is pointing every 16ms.

Now we add in red lines, drawing where the player is aiming after every received mouse input @1000Hz:

With the new High Precision option enabled, projectiles can now travel down any of the red lines! This means you can also functionally shoot between rendered frames (or at high fps, on rendered frames that are in between ticks):

Some additional things worth noting:

This will not change how it “feels” to look around. Looking around will feel the same as it always has, since the final rendered view always took into account any and all raw input messages received from hardware prior to that frame.

Enabling this option does come with a small CPU cost overhead.

Subframe aiming only takes place when a mouse button is either going down or up, and only when using primary or secondary fire. Ie: Holding down primary fire for tracking type weapons will not have any changes to how it behaves.

We hope you enjoy this new feature! We’re always reading and looking for feedback, so please let us know what you think!