• VR Interaction Framework

"Getting Hands On"

One thing that was sorely lacking with the introduction of motion controllers in VR was natural physical interaction. This experiment set out to change that.

In theory motion controllers should make interacting with the virtual world effortless and natural, but in practice there are many cases where the illusion breaks down or things just don't work as you'd expect. This framework was created over the course of several days as an exploration of direct object manipulation in virtual reality. The goal was to come up with a flexible and extendable system that feels right

  • Client

    Independent experiment
    April 2016

  • Results

    Reusable framework v1
    UX insight

  • Details

    Unity/C#
    Supports Vive and Oculus Touch

Features and demo

Two-handed interaction

The system switches seamlessly between single handed and two handed grabs, allowing the user to adjust any object they are holding just like they would in real life. No longer do you need to twist your wrists to pick up an object just the right way.

The system elegantly handles "impossible situations" and works on all interactive objects, allowing the user to forget about being in VR and fully immerse themselves.

Two-handed interaction
Massive objects

Objects respond differently to manipulation depending on their mass. Heavy objects will react slower to input, lagging behind the user's "action" or continuing on their path when the user has already stopped dragging them. Put too much force on your grabbing hand and the object will slip between your fingers.

This is where the distinction between your hands and your action becomes clear. By visualising this difference, the system retains a responsive feeling while making heavy objects truly more difficult to manipulate.

Inertia and momentum in heavy objects
Grip strength
Precision

Not all object manipulation is free and unconstrained. Controls like levers, sliders, switches, dials and others all require the manipulated object to follow a certain path or stay in a certain orientation. Precision placement of objects becomes much easier by applying simple alignment snaps.

Hands On's constraint system can be used and extended for a range of applications. This makes it just as suitable for inserting a puzzle piece or controlling a valve as it is for throwing a ball.

Levers and sliders
Position/orientation snapping
Support for tools

Sometimes, interaction with an object is more elaborate than a simple pick up and drop. Hands On features various grab modes to facilitate different kinds of object usage.

Besides localized and aligned grabs, objects can be configured as a tool which snaps them to a certain orientation when you pick them up and keeps them there until you drop them again. This frees up buttons and allows for tools like screwdrivers, guns, flashlights or even bows.

Two different grip types

Core idea

"In VR, your hands and your influence on the world are not the same thing."

Nothing stops you from holding your hands further apart than the object you're holding is long. Hands On embraces this separation and makes it clear to the user while handling the cases where it would get annoying.

Ironically, it makes interactions much more intuitive by making them less like real life.

Aims

Hands On set out to realize four qualities that would improve user experience significantly.

It is not that none of these existed yet, but that I felt they had not been unified and made in a way that feels good to the user

Two-handed interaction

We are two-handed creatures.
Using two hands is what comes most naturally to us. So why do most VR experiences handicap us into only using one hand at a time?

Physicality

Everyday objects are not weightless and people do not have infinite strength. For interactions to feel natural, a user needs to sense the weight and volume of an object even if they cannot physically feel it.

Clear feedback

Because you cannot physically feel a virtual object, extra care must be taken to clearly communicate what the user is doing with it. Clever use of haptics and visual feedback can help.

Responsive and deliberate

Game physics feel bad, most of the time. Hands On does not use force/damper systems or rigid constraints to avoid the digital oddities that these systems bring to the table.