Assignment 4 - Report

Overview

Many people are unable to welcome a furry friend into their homes for reasons outside their control. Take care of your own virtual cat in this interactive simulation built specifically for VR. 

Description

According to studies done by Australian psychologists in 2015 [1], interacting with cats provides a number of psychological benefits, including lower stress levels and reduced negative emotions across the board [2]. However, according to the National Library of medicine, approximately 10-20% of people are allergic to cats [3], effectively barring them from these potential benefits. Our application aims to give users access to a virtual cat for the purpose of relaxation and entertainment without worry about allergies or the hassles that come with owning and caring for a real cat, bypassing cleaning up mess, the expense of food, and the emotional weight of mortality. The application places the user inside a virtual house with a cat. The cat moves about of its own volition, but the player can throw objects anywhere in the room to get the cat’s attention. Once engaged, the player can pet the cat, which causes the controllers to vibrate. This is to simulate some of the physical feedback of interacting with an animal in real life.

Interface solution

We believe our choice of using VR to interface with the program was crucial for immersion. Already, studies have shown that VR animals can help significantly with fear exposure therapy [4], and it stands to reason that if virtual animals can incite and then lessen a fear response, they can also induce positive emotions as well. Using VR has already been shown in studies [5] to provoke sympathy for endangered animals to a greater degree than traditional media such as videos or written reports.

By involving the user directly in our virtual cat’s world where their physical actions are somewhat translated into the virtual world, we hope to achieve a greater emotional response than what would be elicited from a traditional keyboard and mouse set up, or even an augmented reality set up where images are ultimately still displayed on a flat screen as opposed to a stereoscopic headset. 

In bygone years, the cost of a VR headset was prohibitive, but in the modern day, with headsets such as the Oculus Quest 2 retailing at around the price of a game console such as the Playstation 5 or Xbox Series X, our application has potential for broad appeal in conjunction with these such devices. 

The main hurdle VR has to overcome for accessibility in the modern day is accommodations for those with disabilities, the lack of accommodations being a point of frustration for many [6]. Most of these accommodations (i.e for movement based disabilities) need to be made in the realm of VR hardware, which is beyond the scope of our project. Nevertheless, we believe the level of immersion achieved with VR correlating to increased empathy for depicted subjects in a VR environment outweighs accessibility concerns for the time being.

Interaction Design

The application has three main interactions. The first of these is the ability for the player to pick up an object and throw it somewhere inside the room, which piques the cat’s attention. This gives the player some control over where the cat is in the room, even with the cat’s sporadic movement. The second is the ability for the player to pet the cat, resulting in haptic feedback on the player’s controllers that varies with the speed of the controllers. The third is the ability to pick up and drop a food box on the cat's bowl to fill the bowl up with food, causing the cat to come over and eat the food. These interactions add to the immersion of the application, ensuring that interactions with the virtual cat are as convincingly realistic as possible.

In future, we hope to implement a more complicated cat mood system that dictates how the cat behaves. Under this system, a cat in a good mood would be more receptive to petting and playing than a cat in a bad mood, and the cat’s mood would change somewhat randomly. A cat in a neutral mood might react positively or negatively to being handled, and from there, it might be easier or harder to interact with the cat depending on if the cat’s mood declines or improves. This mood system would be based in one script that interacts with other scripts. 

Other features we intend to implement include (similar to the mood system) a hunger system, objects beyond the test object for the cat to interact with, and cat customisation.

Since most of the features we have planned involve the user's hands interacting with the cat in some way, we believe this justifies the use of VR for our project- no other interface allows for mapping the user's hands to virtual hands as closely as VR does. In terms of currently implemented features, haptic feedback applied directly into the user's hands, while limited to vibration, is not possible with a traditional keyboard and mouse set up and unfocused if used at all with a regular controller or mobile phone running an AR application.

Technical Development

The program was developed in Unity using the Oculus development tools and an Oculus Quest 2 headset with plans to build an application for the Oculus Quest that can run natively.

Our prototype thus far is limited to random cat roaming, placing an object the cat becomes interested in, tactile feedback from petting the cat (controller vibration), and a food mechanic. The implementation of these features is relatively simplistic for the moment. Every so often, the cat picks a direction to go and moves towards it. Likewise, the test object the cat can interact with simply tells the cat to move to its location after it hits the ground, and the food box simply makes the cat's food appear in the bowl, with the cat pausing in front of it for a few seconds until the food is gone. The current features are implemented with a limited number of scripts, one for random cat roaming, one for cat-engaging objects, one for cat feeding, and one for controller vibration. 

The vibration sent to the controllers by petting the cat is directly proportionate to how hard you pet the cat, which in future might also be used to encourage users to pet the cat calmly.

The cat navigates its surroundings using Unity's navmesh system. The cat as a navmesh agent can be directed to go anywhere on the navmesh through code, which currently only encompasses the floor of the living room, but might extend to the ledges in the living room, providing the cat with places to leap to and from.

All future features would require at least one script for each feature, and in future, we would like to provide the cat with convincing animations (or at the least, more convincing than a static cat model sliding across the floor), which include walking, running, playing, eating, and idle animations. These can be be done in the 3d modelling suite Blender (the software was also used to create the bowl model below).

3D Models

Cat model, the main focal point of the application. The cat model was designed for use in games, so it is well optimised for our purposes. The cat model, being the focal point, is of a higher resolution than background objects.

Model used as the application’s environment, containing walls, a floor, and various decorations including a garden, skirtings, and lamps. Most of the assets here are relatively low-resolution, which would help our application to easily build to Oculus Quest devices without a loss of performance.

Bowl model, used for feeding the cat. This model, while low resolution to fit with the background assets, is also rendered with smooth shading to give the impression the edges are softer than they are. 

We had planned to model most other 3d assets for the future ourselves.

Conclusion

The application in its current state allows users to experience a simple simulation of some of a cats basic behaviours in response to humans, without the mess or added expenses that come from owning a real cat. As well as this, it removes the hindrance of allergies, allowing users who cannot interact with cats normally to experience some of the benefits of cat ownership.

References

[1] Strade & Gates, 2015 https://www.tandfonline.com/doi/abs/10.2752/089279393787002385

[2] Newman, 2019 https://www.healthline.com/health/benefits-of-being-cat-lover#2.-Stress

[3] Sparkes, 2021 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8721548/ https://www.frontiersin.org/articles/10.3389/frvir.2022.782023/full

[5] Pimentel & Kalyanaraman https://www.nature.com/articles/s41598-022-10268-y

[6] Phillips, 2020 https://blogs.scientificamerican.com/voices/virtual-reality-has-an-accessibility-problem/

House Interior - https://www.models-resource.com/3ds/nintendogscats/model/30284/

Cat - https://sketchfab.com/3d-models/cat-murdered-soul-suspect-836312def1b84e588866500a2bf79f0f

Bowl - Created by Cade