Haptics in Gaming: Coming of Age

By Chris Ullrich, CTO at Immersion

When I started my career in haptics over 20 years ago, I worked mostly on military and industrial virtual reality systems with high quality (and expensive) haptic feedback. When Sony put haptics in the DualShock controller, more than 20 years ago, I was excited to see haptics becoming mainstream. There was still a big difference between rumble and the high-end experience I was used to. In the real world, haptics in a consumer device has always been an exercise in trade-offs with low budgets. That’s is why I’m ecstatic with Sony’s newly announced PlayStation 5 controller that has not just high definition (HD) vibration but also kinesthetic triggers. 

This new controller represents a whole new level of the tactile experience. As a game developer, why should you care about this new controller’s haptic capabilities? What can this capability do to enhance your game and increase user immersion? Let’s unpack this a little bit. 

What is HD Haptics? 

The two motors in a standard DualShock controller are eccentric rotating mass (ERM) motors. What this means is that as you turn up the voltage, these motors spin faster and make more vibration. Ultimately, developers have only a single number to adjust for each motor, and this number changes both the frequency and the strength of the vibration. This is great because it’s easy to make simple effects, especially if developers are looking for a rumble sensation. However, effects that are subtle, sharp, or high bandwidth are simply not possible with this hardware.  

More than a decade ago, haptic researchers developed a high-bandwidth vibration motor, called a voice coil, that operates more like a speaker than an ERM. These motors enabled developers to control both frequency and strength independently as well as create subtle and sharp sensations. The key problem: these motors were expensive and power-hungry. The good news? In the last few years, these issues have been resolved by various motor manufacturers, and now it’s possible to use these motors cheaply and efficiently to create HD haptics.  

What are Trigger Haptics? 

The triggers on a standard DualShock controller move a small amount and, in the PS4, were resisted by a constant spring force. This means that all trigger pulls feel identical whether the player is shooting a shotgun or driving a Formula 1 car. A relatively new idea is to add resistive force feedback to triggers. This changes the spring to a motor that can modulate the springiness of the trigger – in effect enabling developers to make each trigger feel different. In a game, each weapon can now feel different depending on the weapon. All out of ammo? Well, the trigger has no resistance – players will quickly see the value of this type of feedback. Firing a giant bazooka? Well, the trigger is really hard to pull – you gotta mean it. 

But weapon triggers are just the beginning. As noted in the Wired article, using a bow with haptic triggers is a magical experience. The tension of the bow can be felt by the player. Driving a car over pavement and dirt can feel different – as they would in the pedal of a real car. The opportunities are really endless, especially when trigger feedback is deeply baked into game interactions. 

Enabling Developers with Haptics 

Given all these new degrees of freedom, game developers will need to foster a new skill in their teams: haptic designer. Somewhat similar to a sound designer, a haptic designer is responsible for creating the control signals that drive deep immersion and bring the game experience to life with powerful tactile feedback. The combination of HD motors and haptic triggers means that each game controller has 4 high-bandwidth effect slots that must be synced up with game audio and animations. Tool developers such as Unity and Unreal – as well as Sony’s native developer tools – need to offer much more sophisticated content creation tools to allow these experiences to be explored and delivered to players. 

Players are the Winners 

At the end of all this is, almost certainly, a deeper level of immersion in PS5 games vs. previous generations. Haptic feedback is a different animal than visuals and audio; however, these three modalities, when working together, create an unrivaled immersive experience. This at least begins to bring the high-end virtual reality expected by military and industrial users to the masses. I’m extremely excited to see what developers will do with this new capability, and I’m looking forward to getting my PS5 in 2020!