Methods for Procedural Terrain Generation

Procedural generation has been utilized in the automatic generation of data for a long time. This automated processing has been utilized in the entertainment industry as well as in research work in order to be able to quickly produce large amounts of just the kind of data needed, for example, in system testing. In this thesis, we examine different ways to utilize procedural generation to produce different synthetic terrains. First, we will take a closer look at what procedural generation is, where it originally started, and where it was utilized. From this we move on to look at how this technology is utilized in the creation of terrains and what terrain is generally visually required. From this we move on to look at different ways to implement terrain generation. As part of this thesis, we have selected three methods and implemented our own implementations for terrain generation. We look at the performance of these implementations, and what a test group thinks about those synthetic terrains. The results obtained from this are analyzed and presented at the end of the thesis.Proseduraalista generointia on hyödynnetty datan automaattisessa tuottamisessa jo pitkään. Tätä automatisoitua prosessointia on niin hyödynnetty viihdeteollisuudessa kuin tutkimustyössä, jotta ollaan voitu tuottaa nopeasti suuria määriä juuri sellaista dataa kuin tarvitaan esimerkiksi järjestelmän testauksessa. Tässä tutkielmassa tarkastellaan erilaisia tapoja hyödyntää proseduraalista generointia erilaisten synteettisten maastojen tuottamiseksi. Aluksi tutustutaan hieman tarkemmin siihen mitä proseduraalinen generointi on, mistä se on alunperin lähtenyt ja mihin sitä on hyödynnetty. Tästä siirrytään tarkastelemaan miten kyseistä tekniikkaa hyödynnetään maastojen luomisessa ja mitä maastoilta yleensä visuaalisesti vaaditaan. Tästä siirrytään tarkastelemaan eri tapoja toteuttaa maaston generointia. Osana tätä tutkielmaa, on valittu kolme menetelmää ja laadittu niistä kullekin oma toteutus maaston generointiin. Työssä tarkastellaan näiden toteutusten suoritustuloksia, ja mitä mieltä testiryhmä on kyseisistä synteettisistä maastoista. Saadut tulokset ja niiden analyyysi esitellään tutkielman lopussa

Effects of dynamic vegetation and topography on hydrological processes in semi-arid areas

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.Includes bibliographical references (p. 425-453).Ecosystems of dry climates represent a particularly interesting object for ecohydrological studies, as water is generally considered to be the key limiting resource. This work focuses on vegetation-water-energy dynamics occurring in the complex terrain of a semi-arid area characteristic of central New Mexico. The study constructs a dynamic model of coupled interactions, [tRIBS+VEGGIE], that considers essential water and energy processes over the river basin and links them to the basic plant life regulatory processes. After model calibration, a set of numerical experiments is carried out for two small-scale synthetic domains that exhibit characteristic hillslope curvatures. A weather generator is used to create the long-term series of meteorological forcing. The linkages between terrain attributes and patterns of C4 grass productivity and water balance components are examined for three generic soil types: sand, loam, and clay. It is argued that in conditions of negligible moisture exchange, site aspect and slope are the key determinants of both the hydrologic behavior and the degree of "favorability" to vegetation.(cont.) As shown, certain topographic locations are more favorable to vegetation development, as compared to a flat horizontal surface not affected by lateral effects such as radiative shading or water transfer. These locations are associated with sites of northerly aspect with surface slopes within a narrow range of magnitudes. Contributions from both the rainfall and radiation forcings are discussed to explain the existence of these niches. The sensitivity of results is investigated relative to modifications in the meteorological forcing and the dominant mechanism of lateral water transfer. The analysis unequivocally demonstrates the critical role of soil texture type in regulating the spatio-temporal aspects of coupling between vegetation-hydrology processes. Two additional controlling topographic features are suggested, corresponding to the local and global terrain convergence levels. Furthermore, it is argued that grass productivity and water fluxes of a site can be characterized as a function combining local and global terrain properties.by Valeriy Yuryevich Ivanov.Ph.D

Procedural content generation for games

Virtual worlds play an increasingly important role in game development today. Whether in the entertainment industry, education, collaboration or data visualization - virtual space offers a freely definable environment that can be adapted to any purpose. Nevertheless, the creation of complex worlds is time-consuming and cost-intensive. A classic example for the use of a virtual world is a driving simulator where learner drivers can test their skills. The goal of the generation process is to model a realistic city that is large enough to move around for a long time without constantly passing places that have already been seen. Streets must be realistically modeled, have intersections, represent highways and country roads and create an image through buildings that create the greatest possible immersion in the virtual world. But there is still a lack of life. Pedestrians have to populate the streets in large numbers, other cars have to take part in the traffic, and a driving instructor has to sit next to the learner driver, commenting on the actions and chatting away on long journeys. In short, the effort to model such a world by hand would be immense. This thesis deals with different approaches to generate digital content for virtual worlds procedurally i.e., algorithmically. In the first part of this thesis, virtual, three-dimensional road networks are generated using a pre-defined network graph. The nodes in the graph can be generated procedurally or randomly or can be imported from open data platforms, e.g., from OpenStreetMaps (OSM). The automatic detection of intersections makes the generation flexible. The textures used for roads and intersections are constructed from prefabricated sprites whenever possible, or, in the case of a very individual construction, are newly generated during generation. The ability to create multi-lane roads gives the virtual cities a higher degree of realism. The interstices of the road network usually contain buildings, industrial areas, common areas or agricultural land. Once these so-called parcels have been identified, they can be populated with precisely these contents. In this dissertation we focus on accessible residential buildings. The second part of this thesis discusses a novel method of building generation that allows to procedurally create walk-in, multi-storey buildings. The proceeding of simple mesh generation as shown in the road network generation is extended by rules and constraints that allow a flexible floor planning and guarantee a connection of all rooms by a common corridor per floor and a staircase. Since a cityscape is usually characterised by different building shapes, the generation can be parameterized with regard to texturing, roof design, number of floors, and window and door layout. In order to ensure performance when rendering the city, each building is generated in three levels of detail. The lowest level only shows the outer walls, the highest level shows the interior rooms including stairs, doors and window frames. Once the environment is created in a way that allows the player a certain immersion, the game world has to be filled with life. Thus, the third part of this thesis discusses the procedural creation of stories for games based on pre-trained language models. The focus here is on an interactive, controlled way of playing, in which the player can interact with the objects, persons and places of the story and influence the plot. Actions generated from the entities of the previous section of the story should give a feeling of a prepared story, but always ensure the greatest possible flexibility of course. The controlled use of places, people and objects in the player's inventory allows a porting to a three-dimensional game world as well as the gameplay in the form of a text adventure. All methods for creating digital content presented in this thesis were fully implemented and evaluated with respect to usability and performance

Parameterized and Dynamic Generation of an Infinite Virtual Terrain with Various Biomes using Extended Voronoi Diagram

The paper describes and extensively evaluates a new method for the parameterized and intelligent generation of an infinite environment including various biomes in a virtual 3D space defined by the user. The biomes might be generated with different set of textures and by using different formulas to form shape of the landscape. Despite different shapes they still blend smoothly between each other. To achieve this goal Gaussian blur and Voronoi diagram algorithms are used. To enable additional parameterization for biomes placement the standard Voronoi algorithm is extended by including cell change along an axis and dispersion of Voronoi cells. Applying latitude into terrain type produces more realistic results. An entire terrain is generated on the CPU using a separate thread to eliminate stuttering during calculations and then the data is sent to the GPU in order to draw it. It forces reducing amount of data as much as possible, because data must be sent through the graphical bus. The tests have been performed by setting up a sample terrain and performing basic actions on this terrain like moving or rotating to gather frame times. The results showed that although the method demands much memory it is efficient and suitable for the real-time processing

Parameterized and Dynamic Generation of an Infinite Virtual Terrain with Various Biomes using Extended Voronoi Diagram

The paper describes and extensively evaluates a new method for the parameterized and intelligent generation of an infinite environment including various biomes in a virtual 3D space defined by the user. The biomes might be generated with different set of textures and by using different formulas to form shape of the landscape. Despite different shapes they still blend smoothly between each other. To achieve this goal Gaussian blur and Voronoi diagram algorithms are used. To enable additional parameterization for biomes placement the standard Voronoi algorithm is extended by including cell change along an axis and dispersion of Voronoi cells. Applying latitude into terrain type produces more realistic results. An entire terrain is generated on the CPU using a separate thread to eliminate stuttering during calculations and then the data is sent to the GPU in order to draw it. It forces reducing amount of data as much as possible, because data must be sent through the graphical bus. The tests have been performed by setting up a sample terrain and performing basic actions on this terrain like moving or rotating to gather frame times. The results showed that although the method demands much memory it is efficient and suitable for the real-time processing

Spatial Interaction of Agricultural Land Uses and their Impacts on Ecosystem Service Provision at the Landscape Scale

The relationship between agricultural land use and it impact on ecosystem services, including nutrient cycling and biodiversity conservation, is extremely complex. This complexity has been augmented by isolated research on the impact of agriculture land uses on the landscape's capacity to provide ecosystem services (ES) particularly in most vulnerable areas of Sub-Saharan Africa. Though a considerable number of studies emphasize the nexus between specific land use types and their impact on N-deposition across agriculture landscapes, a sufficient modeling basis for an empirical consideration of spatial interactions between different agricultural land use types at the landscape scale across rural-urbanizing areas in Sub-Saharan Africa is consistently missing. In view of this, the motivation to understand, assess and address significant roles that size, shape, spatial location, and interactivity of different land use patch types play in assessing land use interactions and their impact on ecosystem service provision and the overall landscape resilience necessitated the core of this PhD thesis. This thesis aimed at finding answers to the question of which assessment framework could be employed to understand the interaction of land use types and their impact on ecosystem services, the present thesis introduces a semi-quantitative assessment framework implemented in the GISCAME suite to provide scientific and practical answers to this question. Ahead of the framework development, a thorough review of land use planning documents from selected countries within the WASCAL project area to uncover the key relevance government places on incorporating the ES concept was undertaken. This was with the view that mentioning the concept in such legal document alone does not suggest its relevance if road maps for their implementation is not sufficiently provided, with laid down institutional provisions, roles, responsibilities, support systems and commitments. The outcome of this objective significantly influenced the subsequent objectives of this thesis. Subsequently, I employed Voronoi tessellation and midpoint displacement algorithms implemented in the Structure Generator (SG4GISCAME) to generate alternative land use mosaics to mimic the patchy agricultural landscape character of the study area. The key objective here was to present the output of this alternative landscape as a partial solution to the data scarcity issue which hinders mapping and hypothetical testing of the landscape structure and their role in landscape resilience. To achieve the objective of identifying core sets of landscape indicators to explore the significant influence of the landscape structure and pattern as an influence on landscape resilience, I employed analytical and statistical multivariate principal component and factor analysis to eliminate the landscape metric redundancy. The outcome helped to propose core set as indicators capable to be used for ecosystem services assessment and land use planning. The result revealed that only 6 landscape metrics had the capacity to explicitly define the configuration and compositional landscape character of the Vea catchment area. This result served a critical input into the development of the assessment framework. In developing a framework to assess the contribution of the landscape spatial structure to the resilience of the socio-ecological system (SES), I mapped the capacity of the landscape structure to provide regulating ecosystem services with the aid of land use maps as proxies. Analytical Hierarchical Processes and Expert stakeholder approaches were used to identify and subsequently map key regulating ES identified from the catchment area. Following, a multi-criteria analysis was employed to link stakeholder mapping and landscape metrics to provide a functional understanding of the interrelationship of both methods and how they provide integrative insights into the landscape resilience and ES trade-off concepts respectively. This assessment was undertaken using a 2012 multi-temporal RapidEye land use classification data and implemented with the aid of the cellular automaton module in GISCAME. In the absence of explicit ecological modeling and spatial data, the result of this methodology provides a comprehensively rich ES assessment approach not only for the research area, but for transferability across West Africa. The result of this assessment is to inform, across governance levels, different planning, and development scenarios with the potential to alter the landscapes structural character and thereby impede ES flow and resilience of the SES. Indirectly, the relevance of the landscape structure to land use planning was significant across the outcomes of the thesis. Further, the approach establishes potential trade-offs and synergies across the agricultural landscapes structure and thereby suggest planning and management supports to optimize agricultural production and improve ecosystem service flows in Sub-Saharan Africa. Overall, the implementation of the multi-criteria evaluation function in GISCAME demonstrated beyond question, the functional relevance of the GISCAME software tool as the only tried and tested ES integration framework implemented within the WASCAL project area

Quantitative Techniques in Participatory Forest Management

Forest management has evolved from a mercantilist view to a multi-functional one that integrates economic, social, and ecological aspects. However, the issue of sustainability is not yet resolved. Quantitative Techniques in Participatory Forest Management brings together global research in three areas of application: inventory of the forest variables that determine the main environmental indices, description and design of new environmental indices, and the application of sustainability indices for regional implementations. All these quantitative techniques create the basis for the development of scientific methodologies of participatory sustainable forest management

Quantitative Techniques in Participatory Forest Management

Forest management has evolved from a mercantilist view to a multi-functional one that integrates economic, social, and ecological aspects. However, the issue of sustainability is not yet resolved. Quantitative Techniques in Participatory Forest Management brings together global research in three areas of application: inventory of the forest variables that determine the main environmental indices, description and design of new environmental indices, and the application of sustainability indices for regional implementations. All these quantitative techniques create the basis for the development of scientific methodologies of participatory sustainable forest management