Hello everyone, my name is Chih-Wei Ning.
Today, I’m gonna present Haptic-Go-Round
a surrounding platfrom for encounter-type haptics in virtual reality experiences
This work is done by me and my fellows from National Taiwan University.
Haptic-go-round is a merry-go-round like platform.
With this platform, VR experience designers could deploy props and devices to provide haptic feedbacks.
you can see from this video, a user wearing VR headset is holding a controller, that is attacheed to the platform.
As the whole platform rotates, the user feels force feedback.
Okay let’s start with why we do this work
Researchers have proposed different haptic approaches, to enhance immersion in virtual reality.
Some of them present physical geometries, some simulate texture, and some provide force feedback.
However, most of these devices are specialized for limited use cases.
In order to provide haptic feedback in more general cases, encounter-type haptics are first proposed in 1993 in the work “Robotic graphics”.
This approach often include robots or humans that carry interactive devices to the right place, at the right moment.
It also enable hands-free interactions. And can reuse single physical device as several virtual objects.
However, there’re several downside:
First of all, switching equipment is inefficient;
Also, adding additional actuators costs much and requires complicated calculation.
Such as planning the path and picking objects.
So it is hard to scale up.
Finally the working range is often limited.
As a result, it is quite difficult for designers to really use encounter-type haptics in there VR applications.
To solve this problem, we were inspired by previous works and focus on creating immersive space using circular system.
So, we present Haptic-Go-Round.
Classic encounter-type haptics usually use multiple high degree of freedom actuators, and carry only one equipment at a time.
Our key idea is: we want to use less Degree of freedom, but carry multiple components around the user, at the same time.
We provide both hardware and software interfaces for more agile deployment in VR applications.
Let me show you how HGR can be used in a VR application designing process
I’m gonna develop an immersive “Warship” game
First of all, we need a driving system to navigate the boat.
We want a steering wheel to control the direction, and a lever to control the throttle
So, we made the corresponding props
and we insert them into two of the cartridge slots on the platform
the RFID reader on the platform would read the tag on the prop.
And automatically register it into Unity application.
Then, we can adjust the position of virtual objects in Unity editor.
As you can see, the software interface shows a transparent ring as the indicator of the real position of HGR.
To spice up the cruise, we decided to add some pirates in our experience.
So, we equip our boat with a telescope that can discover enemies, and a canon to attack enemies.
We use a pair of spade grip to represent the handle of the telescope.
As for the canon, since it has a similar handle as the telescope.
We can just simply reuse the spade-grip.
and then we add a cannonball prop to load the canon.
We then insert them as well
Now that in our Warship game, we can drive the boat, discover enemies, and shoot down enemies.
Since the telescope and the canon share the same physical prop, user may have to wait for the platform to rotate to the right position.
If it’s not ready, the system would highlight the contour to warn the user.
Finally, we want to add a full-body intensive interaction: fishing
This time, instead of making our own prop, we decide to use the VR controller as the fishing rod.
We connect the controller to a prop cartridge with an elastic rope.
As the ring rotates, the user could feel the force feedback as if a marlin is dragging the fishing rod around.
Let me show you more examples of HGR integrating with existing game types.
Let's begin with a first person shooter game.
We mount a Nerf gun that can simulate enemies shooting from any directions all around the user.
In this example, we show that HGR enable full-directional interaction that is not only limited to the front of the user.
We can mount a button, and create a 360-degree rhythm game.
We could also mount more than one buttons, so that the average distance of rotation is smaller, and thus the reaction time could be shorter.
In this game, we demonstrate how HGR can reuse one single haptic component as multiple virtual objects.
The surrounding platform also enable large-scale bimanual interactions.
In our room escaping game. The user grabs an electric plug and a socket in each of his hands on the two sides of the platform
He then connect them to open the door.
With above examples, we’ve demonstrated several functionalities of Haptic-Go-Round.
First, HGR rotates haptic components to the right place, at the right time to provide right haptic feedback.
Second, HGR could work with lots of type of haptic components.
Designers could mount either customized prop or existing VR controllers.
Third, with our platform, single haptic component could be reused for multiple virtual objects.
Forth, HGR could provide force feedback by the movement of platform
Finally, the surrounding platform could provide more immersive experiences,
such as bimanual interaction and all-directional interaction.
there’re even more to explore with any props system that you can imagine.
In the next part, I’m gonna talk about how we design haptic-go-round.
Our goal is to create a minimal platform as mentioned to support full-body interactions.
We design our platform based on the following consideration
We set the shape to be a uniform ring, so that every prop has the same distance to the user.
The scale is set to be just fit for a user to reach the prop with his hand simply raise.
As for the degree of freedom, since one of our primary goals is to reduce the complexity of using encounter-type haptics.
We decided to use only one actuator, that is, a ring frame that spins independently.
Our system consists of four parts. The first part is the hardware skeleton.
We used 2 metal wheels to create a ring frame for prop cartridges
And put a turntable on the bottom to make the whole platform rotatable
The ring and the turntable are rigidly connected by aluminum profiles.
The second part is the control system
We use a DC motor to friction-drive the turntable.
2 infrared sensors and printed black-and-white stripes make up the incremental encoder.
With the input from the encoder and the output to the motor, we implemented PID control to rotate the platform.
The third, and the most important part, is our plug-and-play prop cartridges system.
Our prototype contains 8 empty slots for cartridge to insert in.
Each slot is made up with 2 markers for inside-out-tracker to calibrate, and an RFID reader to identify the prop.
To mount a prop, user can easily attach their haptic component to a 5-mm acrylic sheet.
Because acrylic sheets are flat and easy to modify.
Finally, is our software system.
We provide an interface that displays the 3D model of Haptic-go-round, as an indicator to locate virtual object in the Unity editor.
The software server is also the communication center of other parts, in order to provide real-time interactions.
You can find more implementation details and technical specs in the paper.
To evaluate our work, we conducted 2 user studies
In the first study, we want to answer the question:
Does the haptic feedback provided by HGR improve user experience?
We recruited 12 participants to try out our Warship game in two conditions:
one with haptic-go-round, and the other have no haptic feedback as the baseline.
After each condition, we had them rate their level of enjoyment and realism.
From the plot we can see that, Haptic-Go-Round got higher ratings in both aspects,
which suggests that our platform do provide appropriate haptic feedback.
However, several participants complained about the misalignment between physical props and virtual objects
This is mainly come from improper tracking of the props
So we might need more accurate sensing techniques to avoid this.
we wanted to further validate HGR as a designing tool, we conducted in-depth interviews with experience designers
We recruited 12 designers. We provided a hands-on walkthrough of the system
then we interviewed them with 2 main directions:
how would they integrate the system with their former projects and
how would they develop a new experience with Haptic-go-round.
All designers who have worked with VR said that they could integrate Haptic-go-round with their previous projects.
And 9 of the participants are willing to use our platform for their future applications.
During the interview, we also received plenty of creative feedback.
For example, 4 of the designers proposed adventure game.
Because this type of game often include a lot of interactive objects.
Also, 3 of them see the opportunity to integrate special modules with our platform
such as heat and odor
However, several participants want us to provide sample props and corresponding scripts. So that they can speed up their development.
More ideas are discussed in the paper.
After the interview, we continued to work with 2 of the participants, and finished the design of two scenes:
First, is a battle game. User can open up a circular menu and select weapons in it.
The second one is a hammer throwing game. Our platform provide force feedback in this game.
Hammers with different weight could be simulated by controlling the resistance from the platform.
The interview show that Haptic-go-round allows VR experience designers to deploy encounter-type haptics in existing applications as well as new ones.
But, both the software interface and the prop cartridge could be further optimized.
There are several limitations of our work.
First of all, is the rotating latency and the resolution
These are mainly caused by the micro controller we use.
Second, is the fact that our platform requires designers to take extra considerations in several aspects
Such as prop tracking. This is very important, in order to avoid the misalignment mentioned in study 1.
Also, if the designer want to use an active prop, they will have to handle the communication between the props and the server on their own.
However, making use of existing VR controllers could largely avoid these situations.
Finally, what we are proposing here is the minimal but not the optimal set-up.
The degree of freedom in our system is currently limited to the yaw rotation.
We can definitely extend it to have more but reasonable degrees of freedom.
In our future work
we plan to add linear actuators for radiation movement and stack more than one ring frame to create a multi-layered Haptic-go-round system.
We will also integrate with an omni-treadmill to allow locomotion.
Finally, I’d like to conclude our work with 2 takeaways.
First of all, we’ve presented HGR, which is aiming to bring the deployment and development of encounter-type haptics to a more pragmatic level.
We provide both hardware and software interfaces so that designers can easily mount a lots of types of haptic components
This component could be whatever you want
In the sample experiences, we’ve shown that how our platform could be used with both self-made props and existing VR controllers.
With this work, we’re seeking the chance to provide a platform that could integrate most kinds of haptic devices
Such as controller-based devices, shape display, and so on.
Secondly, we see Haptic-go-round as a novel type of VR arcade machine.
Most of the current machines only allow user to interact with one single object in a very limited region at all time.
Our surrounding platform can provide all-directional interaction.
We also provide large scale interaction with user simultaneously using multiple objects.
Together with an omni-treadmill, we see that Haptic-go-round is a feasible solution in future VR arcades.
With this work, we want to bring haptic feedback into these kind of arcade set-up machine
and create more immersive experience.
This is the end of my talk, thank you very much!