-
Raluca D. Gaina, Simon M. Lucas, Diego Perez-Liebana,
"Tackling Sparse Rewards in Real-Time Games with Statistical Forward Planning Methods",
in AAAI Conference on Artificial Intelligence (AAAI-19),
33,
pp. 1691-1698,
2019.
[Abstract]
[DOI]
Abstract
One of the issues general AI game players are required to deal with is the different reward systems in the variety of games they are expected to be able to play at a high level. Some games may present plentiful rewards which the agents can use to guide their search for the best solution, whereas others feature sparse reward landscapes that provide little information to the agents. The work presented in this paper focuses on the latter case, which most agents struggle with. Thus, modifications are proposed for two algorithms, Monte Carlo Tree Search and Rolling Horizon Evolutionary Algorithms, aiming at improving performance in this type of games while maintaining overall win rate across those where rewards are plentiful. Results show that longer rollouts and individual lengths, either fixed or responsive to changes in fitness landscape features, lead to a boost of performance in the games during testing without being detrimental to non-sparse reward scenarios.
BibTex
@inproceedings{gaina2019sparse-rewards,
author= {Raluca D. Gaina and Simon M. Lucas and Diego Perez-Liebana},
title= {{Tackling Sparse Rewards in Real-Time Games with Statistical Forward Planning Methods}},
year= {2019},
booktitle= {{AAAI Conference on Artificial Intelligence (AAAI-19)}},
volume= {33},
pages= {1691--1698},
url= {https://www.aaai.org/ojs/index.php/AAAI/article/view/3990},
doi= {https://doi.org/10.1609/aaai.v33i01.33011691},
abstract= {One of the issues general AI game players are required to deal with is the different reward systems in the variety of games they are expected to be able to play at a high level. Some games may present plentiful rewards which the agents can use to guide their search for the best solution, whereas others feature sparse reward landscapes that provide little information to the agents. The work presented in this paper focuses on the latter case, which most agents struggle with. Thus, modifications are proposed for two algorithms, Monte Carlo Tree Search and Rolling Horizon Evolutionary Algorithms, aiming at improving performance in this type of games while maintaining overall win rate across those where rewards are plentiful. Results show that longer rollouts and individual lengths, either fixed or responsive to changes in fitness landscape features, lead to a boost of performance in the games during testing without being detrimental to non-sparse reward scenarios.},
}
-
Raluca D. Gaina, Simon M. Lucas, Diego Perez-Liebana,
"Project Thyia: A Forever Gameplayer",
in IEEE Conference on Games (COG),
pp. 1-8,
2019.
[Abstract]
[DOI]
Abstract
The space of Artificial Intelligence entities is dominated by conversational bots. Some of them fit in our pockets and we take them everywhere we go, or allow them to be a part of human homes. Siri, Alexa, they are recognised as present in our world. But a lot of games research is restricted to existing in the separate realm of software. We enter different worlds when playing games, but those worlds cease to exist once we quit. Similarly, AI game-players are run once on a game (or maybe for longer periods of time, in the case of learning algorithms which need some, still limited, period for training), and they cease to exist once the game ends. But what if they didn’t? What if there existed artificial game-players that continuously played games, learned from their experiences and kept getting better? What if they interacted with the real world and us, humans: livestreaming games, chatting with viewers, accepting suggestions for strategies or games to play, forming opinions on popular game titles? In this paper, we introduce the vision behind a new project called Thyia, which focuses around creating a present, continuous, ‘always-on’, interactive game-player.
BibTex
@inproceedings{gaina2019thyia,
author= {Raluca D. Gaina and Simon M. Lucas and Diego Perez-Liebana},
title= {{Project Thyia: A Forever Gameplayer}},
year= {2019},
booktitle= {{IEEE Conference on Games (COG)}},
pages= {1--8},
url= {https://ieeexplore.ieee.org/document/8848047},
doi= {10.1109/CIG.2019.8848047},
abstract= {The space of Artificial Intelligence entities is dominated by conversational bots. Some of them fit in our pockets and we take them everywhere we go, or allow them to be a part of human homes. Siri, Alexa, they are recognised as present in our world. But a lot of games research is restricted to existing in the separate realm of software. We enter different worlds when playing games, but those worlds cease to exist once we quit. Similarly, AI game-players are run once on a game (or maybe for longer periods of time, in the case of learning algorithms which need some, still limited, period for training), and they cease to exist once the game ends. But what if they didn’t? What if there existed artificial game-players that continuously played games, learned from their experiences and kept getting better? What if they interacted with the real world and us, humans: livestreaming games, chatting with viewers, accepting suggestions for strategies or games to play, forming opinions on popular game titles? In this paper, we introduce the vision behind a new project called Thyia, which focuses around creating a present, continuous, ‘always-on’, interactive game-player.},
}
-
Raluca D. Gaina, Matthew Stephenson,
"'Did You Hear That?' Learning to Play Video Games from Audio Cues",
in IEEE Conference on Games (COG),
pp. 1-4,
2019.
[Abstract]
[DOI]
Abstract
Game-playing AI research has focused for a long time on learning to play video games from visual input or symbolic information. However, humans benefit from a wider array of sensors which we utilise in order to navigate the world around us. In particular, sounds and music are key to how many of us perceive the world and influence the decisions we make. In this paper, we present initial experiments on game-playing agents learning to play video games solely from audio cues. We expand the Video Game Description Language to allow for audio specification, and the General Video Game AI framework to provide new audio games and an API for learning agents to make use of audio observations. We analyse the games and the audio game design process, include initial results with simple Q-Learning agents, and encourage further research in this area.
BibTex
@inproceedings{gaina2019audio,
author= {Raluca D. Gaina and Matthew Stephenson},
title= {{'Did You Hear That?' Learning to Play Video Games from Audio Cues}},
year= {2019},
booktitle= {{IEEE Conference on Games (COG)}},
pages= {1--4},
url= {https://ieeexplore.ieee.org/document/8848088},
doi= {10.1109/CIG.2019.8848088},
abstract= {Game-playing AI research has focused for a long time on learning to play video games from visual input or symbolic information. However, humans benefit from a wider array of sensors which we utilise in order to navigate the world around us. In particular, sounds and music are key to how many of us perceive the world and influence the decisions we make. In this paper, we present initial experiments on game-playing agents learning to play video games solely from audio cues. We expand the Video Game Description Language to allow for audio specification, and the General Video Game AI framework to provide new audio games and an API for learning agents to make use of audio observations. We analyse the games and the audio game design process, include initial results with simple Q-Learning agents, and encourage further research in this area.},
}
-
Diego Perez-Liebana, Jialin Liu, Ahmed Khalifa, Raluca D. Gaina, Julian Togelius, Simon M. Lucas,
"General Video Game AI: a Multi-Track Framework for Evaluating Agents Games and Content Generation Algorithms",
in IEEE Transactions on Games,
11,
pp. 195-214,
Sep, 2019.
[Abstract]
[DOI]
Abstract
General Video Game Playing (GVGP) aims at designing an agent that is capable of playing multiple video games with no human intervention. In 2014, The General Video Game AI (GVGAI) competition framework was created and released with the purpose of providing researchers a common open-source and easy to use platform for testing their AI methods with potentially infinity of games created using Video Game Description Language (VGDL). The framework has been expanded into several tracks during the last few years to meet the demand of different research directions. The agents are required either to play multiple unknown games with or without access to game simulations, or to design new game levels or rules. This survey paper presents the VGDL, the GVGAI framework, existing tracks, and reviews the wide use of GVGAI framework in research, education and competitions five years after its birth. A future plan of framework improvements is also described.
BibTex
@article{perez2019gvgaisurvey,
author= {Diego Perez-Liebana and Jialin Liu and Ahmed Khalifa and Raluca D. Gaina and Julian Togelius and Simon M. Lucas},
title= {{General Video Game AI: a Multi-Track Framework for Evaluating Agents Games and Content Generation Algorithms}},
year= {2019},
journal= {{IEEE Transactions on Games}},
month= {Sep},
volume= {11},
number= {3},
pages= {195-214},
keywords= {Games;Sprites (computer);Artificial intelligence;Planning;Benchmark testing;Education;Computational intelligence;artificial intelligence;games;general video game playing;GVGAI;video game description language},
url= {https://ieeexplore.ieee.org/abstract/document/8664126},
doi= {10.1109/TG.2019.2901021},
abstract= {General Video Game Playing (GVGP) aims at designing an agent that is capable of playing multiple video games with no human intervention. In 2014, The General Video Game AI (GVGAI) competition framework was created and released with the purpose of providing researchers a common open-source and easy to use platform for testing their AI methods with potentially infinity of games created using Video Game Description Language (VGDL). The framework has been expanded into several tracks during the last few years to meet the demand of different research directions. The agents are required either to play multiple unknown games with or without access to game simulations, or to design new game levels or rules. This survey paper presents the VGDL, the GVGAI framework, existing tracks, and reviews the wide use of GVGAI framework in research, education and competitions five years after its birth. A future plan of framework improvements is also described.},
}
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Olve Drageset, Raluca D. Gaina, Diego Perez-Liebana, Mark H.M. Winands,
"Optimising Level Generators for General Video Game AI",
in IEEE Conference on Games (COG),
pp. 1-8,
2019.
[Abstract]
[DOI]
Abstract
Procedural Content Generation is an active area of research, with more interest being given recently to methods able to produce interesting content in a general context (without task-specific knowledge). To this extent, we focus on procedural level generators within the General Video Game AI framework (GVGAI). This paper proposes several topics of interest. First, a comparison baseline for GVGAI level generators, which is more flexible and robust than the existing alternatives. Second, a composite fitness evaluation function for levels based on AI play-testing. Third, a new parameterized generator, and a Meta Generator for performing parameter search on such generators are introduced. We compare the Meta Generator against random and constructive generator baselines, using the new fitness function, on 3 GVGAI games: Butterflies, Freeway and The Snowman. The Meta Generator is suggested to perform on par with or better than the baselines, depending on the game. Encouraged by these results, the Meta Generator will be submitted to the 2019 GVGAI Level Generation competition.
BibTex
@inproceedings{drageset2019generator,
author= {Olve Drageset and Raluca D. Gaina and Diego Perez-Liebana and Mark H.M. Winands},
title= {{Optimising Level Generators for General Video Game AI}},
year= {2019},
booktitle= {{IEEE Conference on Games (COG)}},
pages= {1--8},
url= {https://ieeexplore.ieee.org/document/8847961},
doi= {10.1109/CIG.2019.8847961},
abstract= {Procedural Content Generation is an active area of research, with more interest being given recently to methods able to produce interesting content in a general context (without task-specific knowledge). To this extent, we focus on procedural level generators within the General Video Game AI framework (GVGAI). This paper proposes several topics of interest. First, a comparison baseline for GVGAI level generators, which is more flexible and robust than the existing alternatives. Second, a composite fitness evaluation function for levels based on AI play-testing. Third, a new parameterized generator, and a Meta Generator for performing parameter search on such generators are introduced. We compare the Meta Generator against random and constructive generator baselines, using the new fitness function, on 3 GVGAI games: Butterflies, Freeway and The Snowman. The Meta Generator is suggested to perform on par with or better than the baselines, depending on the game. Encouraged by these results, the Meta Generator will be submitted to the 2019 GVGAI Level Generation competition.},
}
-
Alexander Dockhorn, Simon M Lucas, Vanessa Volz, Ivan Bravi, Raluca D. Gaina, Diego Perez-Liebana,
"Learning Local Forward Models on Unforgiving Games",
in IEEE Conference on Games (COG),
pp. 1-4,
2019.
[Abstract]
[DOI]
Abstract
This paper examines learning approaches for forward models based on local cell transition function. We provide a formal definition of local forward models for which we propose two learning approaches. Our analysis is based on the game Sokoban, where a wrong action can lead to an unsolvable game state. Therefore, an accurate prediction of an action's resulting state is necessary to avoid this scenario. In contrast to learning the complete state transition function, local forward models allow extracting multiple training examples from a single state transition. In this way, the Hash Set model, as well as the Decision Tree model, quickly learn to predict upcoming state transitions of both the training and the test set. Applying the model using a statistical forward planner showed that the best models can be used to satisfying degree even in cases in which the test levels have not yet been seen. Our evaluation includes an analysis of various local neighbourhood patterns and sizes to test the learners' capabilities in case too few or too many attributes are extracted, of which the latter has shown do degrade the performance of the model learner.
BibTex
@inproceedings{dockhorn2019unforgiving,
author= {Alexander Dockhorn and Simon M Lucas and Vanessa Volz and Ivan Bravi and Raluca D. Gaina and Diego Perez-Liebana},
title= {{Learning Local Forward Models on Unforgiving Games}},
year= {2019},
booktitle= {{IEEE Conference on Games (COG)}},
pages= {1--4},
url= {https://ieeexplore.ieee.org/document/8848044},
doi= {10.1109/CIG.2019.8848044},
abstract= {This paper examines learning approaches for forward models based on local cell transition function. We provide a formal definition of local forward models for which we propose two learning approaches. Our analysis is based on the game Sokoban, where a wrong action can lead to an unsolvable game state. Therefore, an accurate prediction of an action's resulting state is necessary to avoid this scenario. In contrast to learning the complete state transition function, local forward models allow extracting multiple training examples from a single state transition. In this way, the Hash Set model, as well as the Decision Tree model, quickly learn to predict upcoming state transitions of both the training and the test set. Applying the model using a statistical forward planner showed that the best models can be used to satisfying degree even in cases in which the test levels have not yet been seen. Our evaluation includes an analysis of various local neighbourhood patterns and sizes to test the learners' capabilities in case too few or too many attributes are extracted, of which the latter has shown do degrade the performance of the model learner.},
}
-
Simon M Lucas, Alexander Dockhorn, Vanessa Volz, Chris Bamford, Raluca D. Gaina, Ivan Bravi, Diego Perez-Liebana, Sanaz Mostaghim, Rudolf Kruse,
"A Local Approach to Forward Model Learning: Results on the Game of Life Game",
in IEEE Conference on Games (COG),
pp. 1-8,
2019.
[Abstract]
[DOI]
Abstract
This paper investigates the effect of learning a forward model on the performance of a statistical forward planning agent. We transform Conway's Game of Life simulation into a single-player game where the objective can be either to preserve as much life as possible or to extinguish all life as quickly as possible. In order to learn the forward model of the game, we formulate the problem in a novel way that learns the local cell transition function by creating a set of supervised training data and predicting the next state of each cell in the grid based on its current state and immediate neighbours. Using this method we are able to harvest sufficient data to learn perfect forward models by observing only a few complete state transitions, using either a look-up table, a decision tree, or a neural network. In contrast, learning the complete state transition function is a much harder task and our initial efforts to do this using deep convolutional auto-encoders were less successful. We also investigate the effects of imperfect learned models on prediction errors and game-playing performance, and show that even models with significant errors can provide good performance.
BibTex
@inproceedings{lucas2019gog,
author= {Simon M Lucas and Alexander Dockhorn and Vanessa Volz and Chris Bamford and Raluca D. Gaina and Ivan Bravi and Diego Perez-Liebana and Sanaz Mostaghim and Rudolf Kruse},
title= {{A Local Approach to Forward Model Learning: Results on the Game of Life Game}},
year= {2019},
booktitle= {{IEEE Conference on Games (COG)}},
pages= {1--8},
url= {https://ieeexplore.ieee.org/document/8848002},
doi= {10.1109/CIG.2019.8848002},
abstract= {This paper investigates the effect of learning a forward model on the performance of a statistical forward planning agent. We transform Conway's Game of Life simulation into a single-player game where the objective can be either to preserve as much life as possible or to extinguish all life as quickly as possible. In order to learn the forward model of the game, we formulate the problem in a novel way that learns the local cell transition function by creating a set of supervised training data and predicting the next state of each cell in the grid based on its current state and immediate neighbours. Using this method we are able to harvest sufficient data to learn perfect forward models by observing only a few complete state transitions, using either a look-up table, a decision tree, or a neural network. In contrast, learning the complete state transition function is a much harder task and our initial efforts to do this using deep convolutional auto-encoders were less successful. We also investigate the effects of imperfect learned models on prediction errors and game-playing performance, and show that even models with significant errors can provide good performance.},
}
-
Simon M Lucas, Jialin Liu, Ivan Bravi, Raluca D. Gaina, John Woodward, Vanessa Volz, Diego Perez-Liebana,
"Efficient Evolutionary Methods for Game Agent Optimisation: Model-Based is Best",
in Game Simulations Workshop (AAAI),
2019.
[Abstract]
Abstract
This paper introduces a simple and fast variant of Planet Wars as a test-bed for statistical planning based Game AI agents, and for noisy hyper-parameter optimisation. Planet Wars is a real-time strategy game with simple rules but complex game-play. The variant introduced in this paper is designed for speed to enable efficient experimentation, and also for a fixed action space to enable practical inter-operability with General Video Game AI agents. If we treat the game as a win-loss game (which is standard), then this leads to challenging noisy optimisation problems both in tuning agents to play the game, and in tuning game parameters. Here we focus on the problem of tuning an agent, and report results using the recently developed N-Tuple Bandit Evolutionary Algorithm and a number of other optimisers, including Sequential Model-based Algorithm Configuration (SMAC). Results indicate that the N-Tuple Bandit Evolutionary Algorithm offers competitive performance as well as insight into the effects of combinations of parameter choices.
BibTex
@inproceedings{lucas2019efficient,
author= {Simon M Lucas and Jialin Liu and Ivan Bravi and Raluca D. Gaina and John Woodward and Vanessa Volz and Diego Perez-Liebana},
title= {{Efficient Evolutionary Methods for Game Agent Optimisation: Model-Based is Best}},
year= {2019},
booktitle= {{Game Simulations Workshop (AAAI)}},
abstract= {This paper introduces a simple and fast variant of Planet Wars as a test-bed for statistical planning based Game AI agents, and for noisy hyper-parameter optimisation. Planet Wars is a real-time strategy game with simple rules but complex game-play. The variant introduced in this paper is designed for speed to enable efficient experimentation, and also for a fixed action space to enable practical inter-operability with General Video Game AI agents. If we treat the game as a win-loss game (which is standard), then this leads to challenging noisy optimisation problems both in tuning agents to play the game, and in tuning game parameters. Here we focus on the problem of tuning an agent, and report results using the recently developed N-Tuple Bandit Evolutionary Algorithm and a number of other optimisers, including Sequential Model-based Algorithm Configuration (SMAC). Results indicate that the N-Tuple Bandit Evolutionary Algorithm offers competitive performance as well as insight into the effects of combinations of parameter choices.},
}
-
Diego Perez-Liebana, Simon M. Lucas, Raluca D. Gaina, Julian Togelius, Ahmed Khalifa, Jialin Liu,
"General Video Game Artificial Intelligence",
2019.
[Abstract]
[DOI]
Abstract
Research on general video game playing aims at designing agents or content generators that can perform well in multiple video games, possibly without knowing the game in advance and with little to no specific domain knowledge. The general video game AI framework and competition propose a challenge in which researchers can test their favorite AI methods with a potentially infinite number of games created using the Video Game Description Language. The open-source framework has been used since 2014 for running a challenge. Competitors around the globe submit their best approaches that aim to generalize well across games. Additionally, the framework has been used in AI modules by many higher-education institutions as assignments, or as proposed projects for final year (undergraduate and Master's) students and Ph.D. candidates. The present book, written by the developers and organizers of the framework, presents the most interesting highlights of the research performed by the authors during these years in this domain. It showcases work on methods to play the games, generators of content, and video game optimization. It also outlines potential further work in an area that offers multiple research directions for the future.
BibTex
@book{gvgaibook2019,
author= {Diego Perez-Liebana and Simon M. Lucas and Raluca D. Gaina and Julian Togelius and Ahmed Khalifa and Jialin Liu},
title= {{General Video Game Artificial Intelligence}},
year= {2019},
publisher= {Morgan and Claypool Publishers},
url= {https://gaigresearch.github.io/gvgaibook/},
doi= {10.2200/S00944ED1V01Y201908GCI005},
abstract= {Research on general video game playing aims at designing agents or content generators that can perform well in multiple video games, possibly without knowing the game in advance and with little to no specific domain knowledge. The general video game AI framework and competition propose a challenge in which researchers can test their favorite AI methods with a potentially infinite number of games created using the Video Game Description Language. The open-source framework has been used since 2014 for running a challenge. Competitors around the globe submit their best approaches that aim to generalize well across games. Additionally, the framework has been used in AI modules by many higher-education institutions as assignments, or as proposed projects for final year (undergraduate and Master's) students and Ph.D. candidates. The present book, written by the developers and organizers of the framework, presents the most interesting highlights of the research performed by the authors during these years in this domain. It showcases work on methods to play the games, generators of content, and video game optimization. It also outlines potential further work in an area that offers multiple research directions for the future.},
}
-
Diego Perez-Liebana, Raluca D. Gaina, Olve Drageset, Ercument Ilhan, Martin Balla, Simon M. Lucas,
"Analysis of Statistical Forward Planning Methods in Pommerman",
in Proceedings of the Artificial intelligence and Interactive Digital Entertainment (AIIDE),
15,
pp. 66-72,
2019.
[Abstract]
Abstract
Pommerman is a complex multi-player and partially observable game where agents try to be the last standing to win. This game poses very interesting challenges to AI, such as collaboration, learning and planning. In this paper, we compare two Statistical Forward Planning algorithms, Monte Carlo Tree Search (MCTS) and Rolling Horizon Evolutionary Algorithm (RHEA) in Pommerman. We provide insights on how the agents actually play the game, inspecting their behaviours to explain their performance. Results show that MCTS outperforms RHEA in several game settings, but leaving room for multiple avenues of future work: tuning these methods, improving opponent modelling, identifying trap moves and introducing of assumptions for partial observability settings.
BibTex
@inproceedings{perez2019pommerman,
author= {Diego Perez-Liebana and Raluca D. Gaina and Olve Drageset and Ercument Ilhan and Martin Balla and Simon M. Lucas},
title= {{Analysis of Statistical Forward Planning Methods in Pommerman}},
year= {2019},
booktitle= {{Proceedings of the Artificial intelligence and Interactive Digital Entertainment (AIIDE)}},
volume= {15},
number= {1},
pages= {66--72},
url= {https://wvvw.aaai.org/ojs/index.php/AIIDE/article/view/5226},
abstract= {Pommerman is a complex multi-player and partially observable game where agents try to be the last standing to win. This game poses very interesting challenges to AI, such as collaboration, learning and planning. In this paper, we compare two Statistical Forward Planning algorithms, Monte Carlo Tree Search (MCTS) and Rolling Horizon Evolutionary Algorithm (RHEA) in Pommerman. We provide insights on how the agents actually play the game, inspecting their behaviours to explain their performance. Results show that MCTS outperforms RHEA in several game settings, but leaving room for multiple avenues of future work: tuning these methods, improving opponent modelling, identifying trap moves and introducing of assumptions for partial observability settings.},
}