Populating Ancient Pompeii with Crowds of Virtual Romans

Pompeii was a Roman city, destroyed and completely buried during an eruption of the volcano Mount Vesuvius. We have revived its past by creating a 3D model of its previous appearance and populated it with crowds of Virtual Romans. In this paper, we detail the process, based on archaeological data, to simulate ancient Pompeii life in real time. In a first step, an annotated city model is generated using procedural modelling. These annotations contain semantic data, such as land usage, building age, and window/door labels. In a second phase, the semantics are automatically interpreted to populate the scene and trigger special behaviors in the crowd, depending on the location of the characters. Finally, we describe the system pipeline, which allows for the simulation of thousands of Virtual Romans in real time

Using blocks to construct 3D shapes and create transformation animations

The objective of this research is to develop methods by which we can use blocks to approximate the shapes of 3D objects and to generate shape transformation animations. Two graphic tools are developed. One assists the animator in constructing 3D shapes with bricks of different sizes and matching up the different shapes. The other tool helps the animator generate a transformation animation of those bricks. Using polygon shape data, these tools can procedurally place the bricks and control their animation. Several different methods for animation are introduced. Those methods provide different ways to generate animation paths of the blocks. The no path animation and the straight path animation are easy for the animator to create and the animation time is easily controlled. The flocking animation will provide more interesting effect

User experience of architectural detailing in virtual urban environment

Architecture and urban design disciplines very much adhere to the use of representations as a tool to aid decision making process. As it is almost impossible to replicate environments in full-scale, both physical and digital representations are therefore restricted by the notions of scale and level of details. These notions are now challenged by the emergence of virtual reality (VR) technology, which allows architects to work with full-scale virtual environments (VEs). However, the taxonomy of architectural representations in VR is not properly defined as discussions in academia are mostly concerned about creating realistic impressions of space, rather than the operational side of different architectural detailing. Thus, in recognizing the operational dimensions of VEs in VR, it is vital to examine the influence of different architectural detailing on the legibility of VEs. This study aimed to suggest a guideline for users’ experience of architectural detailing in a VE for a large-scale urban simulation. This study was executed as an experimental simulation study. In a total of N=96 respondents were divided into four different treatments with n=24 respondents in each VE with a unique level of architectural detailing. They answered the questionnaire surveys and drew cognitive maps after completed navigating within the VEs using VR. Analysis methods used were primarily of content analysis, Kruskal-Wallis H test, and one-way ANOVA. The first analysis phase was environment-specific and the second phase was route and point-specific. In the third phase, the findings from previous phases were triangulated. The most and the least legible VEs were established as per different abilities of interpreting VEs. The operational dimensions of the VEs were established based on the deconstructed architectural detail components namely ‘geometric extrusion’ and ‘distinction’ as the factors influencing legibility of VEs. The operational dimensions of each VE were synthesized based on various criteria derived from the abilities of interpreting VEs. Based on the statistically significant results, the criteria were reduced to ‘understanding VE’ and ‘recalling VE’, in that order. In conclusion, there are some influences of architectural detailing on legibility but only in regards to the two criteria. The operational dimensions were also established for each criterion, which was learned from the cognitive knowledge data. Firstly, is for tasks within one viewpoint. Secondly, is for linear navigation and lastly is for full-fledged virtual exploration. This thesis also proposed two main guidelines for the user experience of architectural detailing in urban VE to be used by architects and users in the associated domain

Increasing the performance and realism of procedurally generated buildings

As multimedia such as games and movies grow, so does the need for content. Textures, 3D models, expansive terrain, sound effects, and other data must be generated to support and enrich these multimedia productions. As this need for content continues to grow, two critical problems emerge: the cost of hiring artists to create the content becomes extremely large, as does the amount of memory needed to store and manipulate the content.;To combat these issues, procedural content generation, or content generated algorithmically rather than via an artist, has been introduced. Algorithmically generating content allows for rapid creation of large amounts of certain classes of content with little human effort; further, this content can be represented extremely compactly, often by only exposing a handful of parameters.;In the realm of 3D building generation, split grammars have proven useful for generating a wide variety of buildings while being relatively intuitive. These split grammars have been used to generate entire cities full of detailed buildings with a fairly small number of rules.;Split grammars have two important areas which can be expanded upon: first, the writing of an appropriate grammar can require a significant amount of work and knowledge, especially when a grammar is required that must follow a certain building style while providing a high degree of variation. Second, applying these grammars to produce a building can be slow, often requiring an offline pregeneration phase which eliminates the usefulness the size benefits of the grammar\u27s compactness.;For the first problem, we propose a data mining approach to refining preexisting grammars, wherein a user can specify buildings which they prefer, and from these preferences a set of rules will be generated that will guide future building generation. We will show that the generated rules have a high degree of accuracy when used to predict whether a user will like or dislike a building, often in the upper 90%.;For the second problem, we provide two areas of improvement: a preprocessing step which parses a split grammar to make it easier and more efficient to apply the grammar without loss of generality, and a scheme that allows the execution of a grammar entirely within a geometry shader on a modern graphics processing unit (GPU) such that building generation can take advantage of the parallelization found on modern graphics cards. We will show that this second improvement can provide a speed benefit anywhere between 3 and 10 times a purely CPU approach, with further speed benefits possible depending on the nature of the grammars

Der Semantic Building Modeler - Ein System zur prozeduralen Erzeugung von 3D-Gebäudemodellen

Computer generated 3d-models of buildings, cities and whole landscapes are constantly gaining importance throughout different fields of application. Starting with obvious domains like computer games or movies there are also lots of other areas, e.g. reconstructions of historic cities both for educational reasons and further research. The most widely used method for producing city models is the „manual“ creation. A 3d artist uses modeling software to design every single component by hand. Especially for city models consisting of hundreds or thousands of buildings this is a very time consuming and thus expensive method. Procedural modeling offers an alternative to this manual approach by using a computer to generate models automatically. The history of procedural modeling algorithms goes back to the 1980s when the first implementations for the automatic texture synthesis were developed and published by Ken Perlin. Other important applications are the generation of plants based on formalisms like L-systems, proposed by Aristid Lindenmayer or particle systems widely used within computer graphics first proposed by William Reeves. Research concerning the applicability of the developed formalisms and techniques led to the creation of systems dedicated to the automatical computation of building and city models. These systems are often differentiated between rule-based and procedural systems. Rule-based systems use formalisms like text replacement systems whereas procedural systems implement every step of the construction process within the program code. The Semantic Building Modeler is a procedural system, which is configured by using user-provided XML-parameters. The semantic meaning of these parameters is fixed through a tight coupling with their usage within the program code. In this point, the semantic of the Semantic Building Modeler differs from other systems on the today’s market. Besides, it facilitates the introduction for novice users making their first experiences with procedural modeling. Concerning the algorithmic aspect the system proposes two new algorithms for the automatic creation and variation of building footprints. These enable the software to create automatically varied building structures. Additionally, the prototype implementation can be seen as an extendable framework. It offers a wide range of algorithms and methods, which can be used for future extensions of the current system. The prototype also contains an implementation of the Weighted-Straight-Skeleton-Algorithm, techniques for the distributed storage of configuration-fragments, the procedural construction of building components like cornice and many more. The prototypical realization of the developed algorithms is a proof-of-concept-implementation. It demonstrates that the usage of semantically based parameters for the procedural creation of complex and visually appealing geometry can go hand-in-hand. This opens the powerful algorithmic construction of building and city models to a big group of users who have no experience neither in the field of programming nor in the manual design of 3d models