Background: Simulation of physics is something several modern video games use. These simulations are often used to create more believable and realistic environments. Physics-based animations in the form of muscle simulations is one such technique. Objectives: The aim of this thesis is to investigate three different stages of full-body muscle deformation and observe which of these are preferred. One using no degree of deformation being the control condition and the other two using different degrees of deformation being the treatments. This study is conducted by creating animationswith three different degrees of muscle simulation. These animations are then rendered in Maya as well as put into a small fighting scenario implemented in Unreal Engine 4. A user experiment will be conducted where a number of participants will be asked to choose between different scenarios using two-alternative forced choice. After the user study is completed, the data will be analyzed and used to form a conclusion. Methods: Implementations needed to create the stimulus was first done in Maya where the meshes, muscles and animations were created. Renders were done in Maya of all animations and a scene was also implemented in Unreal Engine 4 simulating a small fighting game using the assets created in Maya. To evaluate player preference,a user experiment was conducted with 13 participants where each participant was asked to watch 27 scenarios containing two side-by-side comparisons with different degrees of muscle deformation. The user experiment stimulus was created using PshycoPy which also collected the data of user preference. The scenarios where presented in an arbitrary order. The study was held in a room where the participant was undisturbed. Results: The results showed that no muscle deformation was preferred in all cases where a statistical difference could be found. Conclusions: While the results show that the control condition is mostly preferred, most cases did not yield a conclusive result. Thus further research in the area is necessary.

With the introduction of new input devices, such as multi-touch surface displays, the Nintendo WiiMote, the Microsoft Kinect, and the Leap Motion sensor, among others, the field of Human-Computer Interaction (HCI) finds itself at an important crossroads that requires solving new challenges. Given the amount of three-dimensional (3D) data available today, 3D navigation plays an important role in 3D User Interfaces (3DUI). This dissertation deals with multi-touch, 3D navigation, and how users can explore 3D virtual worlds using a multi-touch, non-stereo, desktop display. The contributions of this dissertation include a feature-extraction algorithm for multi-touch displays (FETOUCH), a multi-touch and gyroscope interaction technique (GyroTouch), a theoretical model for multi-touch interaction using high-level Petri Nets (PeNTa), an algorithm to resolve ambiguities in the multi-touch gesture classification process (Yield), a proposed technique for navigational experiments (FaNS), a proposed gesture (Hold-and-Roll), and an experiment prototype for 3D navigation (3DNav). The verification experiment for 3DNav was conducted with 30 human-subjects of both genders. The experiment used the 3DNav prototype to present a pseudo-universe, where each user was required to find five objects using the multi-touch display and five objects using a game controller (GamePad). For the multi-touch display, 3DNav used a commercial library called GestureWorks in conjunction with Yield to resolve the ambiguity posed by the multiplicity of gestures reported by the initial classification. The experiment compared both devices. The task completion time with multi-touch was slightly shorter, but the difference was not statistically significant. The design of experiment also included an equation that determined the level of video game console expertise of the subjects, which was used to break down users into two groups: casual users and experienced users. The study found that experienced gamers performed significantly faster with the GamePad than casual users. When looking at the groups separately, casual gamers performed significantly better using the multi-touch display, compared to the GamePad. Additional results are found in this dissertation.