<p dir="ltr">With the recent virtualization of our everyday lives and the development of intelligent AI technology, realistic virtual agents are becoming a useful tool for research, education, and entertainment. With virtual agents customized content can be created and individualized for specific users. However, virtual agents are only effective tools if they can form a connection with the individual. To form a connection the virtual agent must be believable.</p><p dir="ltr">The literature review evaluates topics of virtual agent believability, appeal, and naturalness and how they relate to asymmetry in facial expression animation. The literature suggests that asymmetries can affect the perception of virtual agents. Additionally, it suggests that emulating human behavior is beneficial to increasing perception of believability, appeal, and naturalness.</p><p dir="ltr">In this study we evaluated the effects of facial expression asymmetry on the believability, appeal, and naturalness of virtual agents. To do this we ran an online perception study with students at Purdue University. We found, in brief, that facial expression asymmetries do have significant effect on the believability, appeal, and naturalness of a virtual agent compared to animations that do not include facial expression asymmetries.</p>

This paper aims to investigate the effect of AI-generated content (AIGC) when it starts to be applied in game development. AIGC in games refers to the generation of game content through artificial intelligence, a concept that has recently recieved a high level of attention due to the latest rapid developments in artificial intelligence, and in traditional research, AIGC can be categorized as an advanced approach to Procedural Content Generation (PCG), i.e., Deep Learning Method. Procedural Content Generation is the creation of game content through algorithms with limited or indirect user input. Its traditional approach has been widely used in games. Recently, however, the AIGC method has also started to be used by a large number of game companies, and its impact has exceeded expectations. A questionnaire survey of 40 game developers revealed a general interest in AIGC but also concerns. Further interviews explored the use of AIGC in game development and some of the problems it has encountered and predicted future trends in its development. The result of this study provide guidance on whether and how AIGC needs to be used in future game development.

Digital painting is the field of software designed to provide artists a virtual medium to emulate the experience and results of physical drawing. Several hardware and software components come together to form a whole workflow, ranging from the physical input devices, to the stroking process, to the texture content authorship. This thesis explores an artist-friendly approach to synthesize the textures that give life to digital brush strokes. Most painting software provides a limited library of predefined brush textures. They aim to offer styles approximating physical media like paintbrushes, pencils, markers, and airbrushes. Often these are static bitmap textures that are stamped onto the canvas at repeating intervals, causing discernible repetition artifacts. When more variety is desired, artists often download commercially available brush packs that expand the library of styles. However, included and supplemental brush packs are not easily artist-customizable. In recent years, a separate field of digital art tooling has seen the popular growth of node-based procedural content generation. 3D models, shaders, and materials are commonly authored by artists using functions that can be linked together in a visual programming environment called a node graph. In this work, the feasibility is tested of using a node graph to procedurally generate highly customizable brush textures. The system synthesizes textures that adapt to parameters like pen pressure and stretch along the full length of each brush stroke instead of stamping repetitively. The result is a more flexible and artist-friendly way to define, share, and tweak brush textures used in digital painting.

I denna uppsats kommer vi att presentera en modell vars syfte är att generera beteende-mönster för rollfigurer i digitala spel. Spelgenren rollspel (eng. Role-playing games) placerarspelaren i en värld fylld av fantastiska monster och modiga hjältar. I ett sådant spel ärde goda karaktärerna minst lika viktiga som de ondskefulla varelser som spelaren kämparmot. Hur ser livet ut för en spelkaraktär när den inte hjälper spelaren på dess äventyr? Dekanske lever som fiskare på havet eller som bönder ute på fältet. Mer troligt är att de bori en by tillsammans med en massa andra spännande karaktärer. Vi undersöker hur sådanakaraktärers vardag ser ut och tittar på en teknik som används för att skapa deras beteen-demönster, Cyclic Scheduling. Tekniken innebär att utvecklare skapar scheman som styrrollfigurernas beteende. Dessa scheman måste skapas i förväg under spelets utveckling ochkräver i stora spel många arbetstimmar för att utvecklas. Modellen vi presenterar i dennauppsats använder tekniken Smart Terrain för att automatiskt generera beteendemönsteroch kan användas för att minska utvecklingstid. Vi diskuterar hur modellen kan användas iföränderliga spelvärldar där utvecklare inte i förhand vet hur spelens omgivningar kommeratt se ut. / In this thesis we present a model for the generation of behaviour patterns for charactersin digital games. In the genre Role-playing games the player is placed in a world filledwith fantastic monsters and brave heroes. In this kind of game the good characters areas important as the evil creatures the player must fight against. What kind of life doesa game character have when not helping the player on adventures? Maybe they live asfishermen on the sea or as farmers in the fields. More likely they live in villages amongstother exciting game characters. We examine what these characters’ daily routines looks likeand look at a technique used for creating their behaviour patterns, Cyclic Scheduling. Thetechnique is used by developers to create schedules that control the behaviour of charactersin games. These schedules have to be created during the game development process andfor bigger games this consumes a lot of time. The model we presents in this thesis uses thetechnique Smart Terrain to automatically generate behaviour patterns thereby reducingthe development time. We discuss how the model can be used in dynamic game worldswhere the developers are unaware of potential changes in the game world.

I denna uppsats presenteras ett verktyg för att assistera skapandet av spelbanor i dungeon-miljö. Skapandet av sådana banor är ofta resurskrävande under produktionen och har fokus på design. För att behålla designaspekten men underlätta arbetet är verktyget framtaget för att med tillgängliga parametrar producera grottgångar för sådana banor. Vi undersöker med användartester hur verktyget kan användas för att effektivisera en känd metod för att skapa spelbanor, men samtidigt skapa den kvalité som eftertraktas. Med detta avser vi inte bara att ta fram ett effektivt verktyg, utan även att demonstrera en metod för att använda procedurell generering av spelinnehåll för ett nytt ändamål inom speldesign. / In this article a tool for assisting the creation of game levels in a dungeon environment is presented. Creating such game levels often requires a large amount of resources during a game production and has focus on design. To keep the aspect of design but ease work, the tool is created to produce caverns for such game levels with accessible parameters. We examine with user tests how the tool can be used to make an existing method for creation of game levels more effective. But at the same time producing the quality that is coveted. With this we do not only hope to produce an effective tool, but also to demonstrate a method for using procedural generation for a new purpose in game design.

Interactive evolution is explored and applied for the automatic generation of 8-bit sound effects (SFX). Procedurally generating a type of content can result in greater accessibility, cut development costs, and more. However, a natural problem that follows this approach is user fatigue. An 8-bit SFX generator is developed, tested, and then evaluated to understand its capabilities, usability, and effectiveness of several applicable solutions for reducing user fatigue. Results indicate that the software is intuitive to learn and use while providing a decent variety to the generated content with a probable feeling of progression. The implemented solutions for abating user fatigue show promise towards making the software practically viable. However, there are still areas in the developed artifact that suggest for further study.

This Master's Thesis was performed at SkyMaker AB in Linköping during the spring of 2024. SkyMaker is a company specializing in CAD automation, and this project explores the integration of Procedural Content Generation (PCG) principles into Computer-Aided Design (CAD) to evaluate their potential benefits for CAD users. The focus of the study is on transitioning from Engineer-to-Order (ETO) to Configure-to-Order (CTO) products. The project has been conducted following a structured research and development process. This included a comprehensive literature review, comparisons of game modelling software, and practical development on the DynaMaker platform. The central aim was to assess the applicability of various PCG techniques in CAD. Concepts were developed and evaluated to determine the feasibility and benefits of integrating PCG principles into CAD software, specifically for designing a colony on Mars. The results highlight the potential of combining CAD with PCG, though at a somewhat simplified and foundational level. Through an iterative process, the project demonstrated the feasibility of PCG in CAD design and its potential benefits. Supported by these findings, the influence of PCG on the shift from ETO to CTO was also presented. The findings and methodologies have been thoroughly documented to support further development in this innovative area.

This thesis explores the possibility of combining a noise-based terrain generator with a multi-agent system-based citygenerator for use in overworld map generation for games.The resulting artifact is a generator capable of creating awide variety of landscapes and populating them with citiesthat take advantage of available space and resources. Thegenerated noise is used as a height map which is colorizedto form the basis of the terrain. City agents traverse the space, looking for an optimal place to settle within their view. Once they find their final position, each city creates a number of building agents based on the nearby resources. The city agents take each other and the terrain into account when deciding where the buildings shall be placed. Then, road agents connectfirst the houses, then the cities together. Lastly, points ofinterests such as dungeons, bandit camps and wizard towers are placed, their final positions determined in a similar fashion to the city agents. The analysis of the results indicate that the generator is capable of producing novel terrain, and cities that adapt somewhat well to their surroundings, but offer little variety in existing features from map to map. In addition, more control is necessary to implement the artifact into adevelopment workflow. Respondents rated the maps produced by the generator lower than a map from an existing game ,converted into a similar format, and on a similar level as another map, also from an existing game.

The present research proposes two procedural content generation approaches for missions and play space in a game with dungeons, and a game prototype developed as a proof of concept for the feasibility of the algorithm and as a test framework for user-based experiments. The first approach will define missions by generating dungeon maps together with locked doors and keys through the use of an evolutionary algorithm. The second approach will populate the generated dungeon space by filling the content of dungeon rooms using space-filling curves and cellular automata algorithms. The evolutionary algorithm evolves tree structures encoding information about the dungeon. The goal is to converge the generated dungeons as close as possible to satisfy the set of parameter inputs provided by a game designer. The dungeon holds information about the amount of rooms, the connections between them and their position in a 2D map. There are also relevant semantic information in the content for the generation of narrative, which presents itself by the placement of unique pairs of keys and locks throughout it. Thus, a feasible way to finish the dungeon can be procedurally generated. The content of rooms are generated using space-filling curves algorithms such as Hilbert and Moore curves as well as Conways Game of Life Cellular Automata. Computational results report that the evolutionary algorithm provides dungeons with up to a 100 rooms very close to the desired ones for a range of different parameter inputs. The early validation tests with humans show no statistical difference between levels procedurally generated and those made by humans. Further user-centred validation tests with the game prototype show the algorithm-generated levels are perceived as equally or even more human-made than their human-authored counterparts, as well as funnier and more difficult. Thus, the research aims to generate gameplay elements combining different algorithms for a single solution, which could be easily adapted to a range of different games. / O projeto propõe duas abordagens de geração de conteúdo para missões e mapas em um jogo com calabouços, e um protótipo de jogo desenvolvido como prova de conceito da factibilidade do algoritmo e também como plataforma de testes para experimentos com usuários. A primeira abordagem define missões ao gerar mapas de calabouço em conjunto com chaves e portas trancadas através do uso de um algoritmo evolutivo. Já a segunda abordagem irá popular o espaço do calabouço criado ao preencher o conteúdo de suas salas usando algoritmos de curvas de preenchimento de espaço e autômatos celulares. O algoritmo evolutivo evolui uma estrutura em árvore que codifica informações sobre o calabouço. O objetivo é convergir os calabouços gerados para se aproximar ao máximo da configuração de entrada fornecida por um designer de jogos. O calabouço possui informação sobre as salas, como a quantidade das mesmas, as conexões entre elas e suas posições em um mapa 2D. Também contam com informações semânticas relevantes para a geração de narrativa no calabouço, que são o posicionamento de pares únicos de chaves e fechaduras através do calabouço. Portanto, uma maneira factível para o término do mesmo pode ser gerada proceduralmente. O conteúdo das salas é gerado usando curvas de preenchiment de espaço como as de Hilbert e Moore, além do autômato celular do Jogo da Vida de Conway. Resultados computacionais demonstram que o algoritmo evolutivo é capaz de criar calabouços com propriedades muito próximas às desejadas para uma grande variedade de entradas para calabouços com até 100 salas. Resultados preliminares de validação com humanos mostraram não haver diferença estatística entre os níveis gerados proceduralmente daqueles feitos por humanos. Testes posteriores de validação centrados em humanos com o protótipo de jogo mostram que os níveis gerados pelo algoritmo são percebidos como feitos por humanos de maneira semelhante ou até em maior grau do que suas contrapartidas geradas de fato por humanos, assim como são percebidos como mais divertidos e difíceis do que estas. Portanto, esta pesquisa objetiva gerar elementos de jogabilidade combinando diferentes algoritmos em uma única solução, que pode ser facilmente adaptada para uma variedade de jogos diferentes.

The present research proposes two procedural content generation approaches for missions and play space in a game with dungeons, and a game prototype developed as a proof of concept for the feasibility of the algorithm and as a test framework for user-based experiments. The first approach will define missions by generating dungeon maps together with locked doors and keys through the use of an evolutionary algorithm. The second approach will populate the generated dungeon space by filling the content of dungeon rooms using space-filling curves and cellular automata algorithms. The evolutionary algorithm evolves tree structures encoding information about the dungeon. The goal is to converge the generated dungeons as close as possible to satisfy the set of parameter inputs provided by a game designer. The dungeon holds information about the amount of rooms, the connections between them and their position in a 2D map. There are also relevant semantic information in the content for the generation of narrative, which presents itself by the placement of unique pairs of keys and locks throughout it. Thus, a feasible way to finish the dungeon can be procedurally generated. The content of rooms are generated using space-filling curves algorithms such as Hilbert and Moore curves as well as Conways Game of Life Cellular Automata. Computational results report that the evolutionary algorithm provides dungeons with up to a 100 rooms very close to the desired ones for a range of different parameter inputs. The early validation tests with humans show no statistical difference between levels procedurally generated and those made by humans. Further user-centred validation tests with the game prototype show the algorithm-generated levels are perceived as equally or even more human-made than their human-authored counterparts, as well as funnier and more difficult. Thus, the research aims to generate gameplay elements combining different algorithms for a single solution, which could be easily adapted to a range of different games. / O projeto propõe duas abordagens de geração de conteúdo para missões e mapas em um jogo com calabouços, e um protótipo de jogo desenvolvido como prova de conceito da factibilidade do algoritmo e também como plataforma de testes para experimentos com usuários. A primeira abordagem define missões ao gerar mapas de calabouço em conjunto com chaves e portas trancadas através do uso de um algoritmo evolutivo. Já a segunda abordagem irá popular o espaço do calabouço criado ao preencher o conteúdo de suas salas usando algoritmos de curvas de preenchimento de espaço e autômatos celulares. O algoritmo evolutivo evolui uma estrutura em árvore que codifica informações sobre o calabouço. O objetivo é convergir os calabouços gerados para se aproximar ao máximo da configuração de entrada fornecida por um designer de jogos. O calabouço possui informação sobre as salas, como a quantidade das mesmas, as conexões entre elas e suas posições em um mapa 2D. Também contam com informações semânticas relevantes para a geração de narrativa no calabouço, que são o posicionamento de pares únicos de chaves e fechaduras através do calabouço. Portanto, uma maneira factível para o término do mesmo pode ser gerada proceduralmente. O conteúdo das salas é gerado usando curvas de preenchiment de espaço como as de Hilbert e Moore, além do autômato celular do Jogo da Vida de Conway. Resultados computacionais demonstram que o algoritmo evolutivo é capaz de criar calabouços com propriedades muito próximas às desejadas para uma grande variedade de entradas para calabouços com até 100 salas. Resultados preliminares de validação com humanos mostraram não haver diferença estatística entre os níveis gerados proceduralmente daqueles feitos por humanos. Testes posteriores de validação centrados em humanos com o protótipo de jogo mostram que os níveis gerados pelo algoritmo são percebidos como feitos por humanos de maneira semelhante ou até em maior grau do que suas contrapartidas geradas de fato por humanos, assim como são percebidos como mais divertidos e difíceis do que estas. Portanto, esta pesquisa objetiva gerar elementos de jogabilidade combinando diferentes algoritmos em uma única solução, que pode ser facilmente adaptada para uma variedade de jogos diferentes.