A Survey of Algorithmic Shapes

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015

The idea of generative modeling is to allow the generation of highly complex objects based on a set of formal construction rules. Using these construction rules, a shape is described by a sequence of processing steps, rather than just by the result of all applied operations: Shape design becomes rule design. Due to its very general nature, this approach can be applied to any domain and to any shape representation that provides a set of generating functions. The aim of this report is to give an overview of the concepts and techniques of procedural and generative modeling as well as their applications with a special focus on Archaeology and Architecture.

Journal on Computing and Cultural Heritage

Digital architectural heritage content creation for virtual worlds nowadays is one of the most important challenges with the ever-increasing expenses of manual content development. Procedural modeling approaches have become a key tool for automating the design and reconstruction of structures and urban environments to disseminate them through appropriate multimedia approaches. This study presents a general architectural modeling system that combines the full generative power of shape grammars with the ease of use and flexibility of procedural modeling parameters which allows for the creation of heritage buildings that adhere to shape grammars. To evaluate the system, we conducted an initial user study with 20 participants from the Al-Zaytoonah University of Jordan to assess the user experience, user impression, and effectiveness of the system. Participants’ feedbacks were encouraging, indicating that the proposed approach could be effective and beneficial in assisting the creation o...

IEEE Transactions on Visualization and Computer Graphics, 2011

We present a method for procedurally modeling general complex 3D shapes. Our approach can automatically generate complex models of buildings, man-made structures, or urban datasets in a few minutes based on user-defined inputs. The algorithm attempts to generate complex 3D models that resemble a user-defined input model and that satisfy various dimensional, geometric, and algebraic constraints to control the shape. These constraints are used to capture the intent of the user and generate shapes that look more natural. We also describe efficient techniques to handle complex shapes, highlight its performance on many different types of models. We compare model synthesis algorithms with other procedural modeling techniques, discuss the advantages of different approaches, and describe as close connection between model synthesis and context-sensitive grammars.

The paper relates to contemporary architectural explorations of complex, curvilinar surfaces in the context of generative computational methods. Traditional ways of representing geometry, based on descriptive methods, favor formal language of "flat elements" easy to map in a rectangular coordinate system and built using traditional technology. In advanced generative computational methods used in the architectural digital design objects are not "drawn”" but they are calculated, which means that the designer does not model directly the external form, but its internal generative logic. This allows automatic generation of variations of solutions, and digital production of "difficult" components of architectural forms using CNC technology. The digital generative methods open up new areas for exploration of formal and tectonic features, accentuate form's ability to emerge and adapt. "Architecture is recasting itself, becoming in part an experimental investigation of topological geometries, partly a computational orchestration of robotic material production and partly a generative, kinematic sculpting of space. ” (P. Zellner. 1999). Topological transformations have primary impact on mutual relations and the geometry of the resulting form. Innovative architectural designs around the world have shown that the use of generative computational methods has great design potential and requires the ability to go beyond the traditional architectural and designing workshop. This ability for future generations of architects may be a subject to competitiveness in the global market.

COMPUTER GRAPHICS forum, 2017

It is a challenge for shape grammars to incorporate spatial hierarchy and interior connectivity of buildings in early design stages. To resolve this difficulty, we developed a bi-directional procedural model: the forward process constructs the derivation tree with production rules, while the backward process realizes the tree with shapes in a stepwise manner (from leaves to the root). Each inverse-derivation step involves essential geometric-topological reasoning. With this bi-directional framework, design constraints and objectives are encoded in the grammar-shape translation. We conducted two applications. The first employs geometric primitives as terminals and the other uses previous designs as terminals. Both approaches lead to consistent interior connectivity and a rich spatial hierarchy. The results imply that bespoke geometric-topological processing helps shape grammar to create plausible, novel compositions. Our model is more productive than hand-coded shape grammars, while it is less computation-intensive than evolutionary treatment of shape grammars.

Procedia Technology, 2014

Virtual reconstructions are commonly used in archaeology to represent cultural heritage monuments that had been lost or damaged by natural causes. Traditionally, these reconstructions require a huge number of human resources and large ranges of time, resulting in high costs of production. To tackle with this issue, many researchers developed semi-automatic techniques to produce virtual models expeditiously. These procedural techniques provide different ways of represent buildings, including interiors and outer facades, in an archaeological or modern context. However, the existing techniques focusing building interiors only support the production of virtual models composed mainly by regular shapes such as rectangles. In this paper it will be presented the first steps of a novel methodology to provide a solution for the generation of building interiors constrained by arbitrary convex shapes. This methodology uses a specific ontology with a set of rules in order to regulate the generation process. The sequence of steps includes the room placement and area definition, section cuts and area readjustments, room linking and finally the extrusions and roof placement to deliver the final 3D model.

A fundamental problem in processing 3D shapes is insufficient knowledge engineering. On the one hand there are numerous methods to design and manufac-ture 3D shapes in the real world. On the other hand, numerous digital methods for representing and processing shape have been developed in computer graphics. Most of these methods make certain assumptions about the kind of 3D objects that they will be used for: A surface smoothing algorithm, for instance, is not well suited for assem-blies of rectangular blocks or for pipe networks. However, it is currently not possible to formulate the properties of a given shape explicitly in an commonly agreed way. This paper is a first step towards classifying structural descriptions of man-made shape. By listing construction principles and principles for their combination it follows a phe-nomenological approach. The purpose is to illustrate the inherent complexity of the domain, and to lay out the foundation for subsequent thorough knowledge engin...

VAST2012: The 13th International Symposium on Virtual Reality, Archaeology and Cultural Heritage; Short & Project Papers, 2012

The ability to automatically generate urban virtual environments using procedural methods is important for anyone who needs to create plausible virtual representations of human settlements, and these techniques are used in simulation and reconstruction of archeaological sites as well as in education and the entertainment industry. In this paper we present an attempt at providing a shape grammar based on the writings of the ancient Roman architect Virtuvius, encoding rules for procedurally defining the make-up of Roman settlements. Our initial results allow the procedural generation of classical Roman Temples, which include many of the architectural elements found in Roman civic buildings. P R E P R I N T

Advances in Architectural Geometry, …, 2008

Various approaches to create geometrical shapes by procedural means are described for applications in art and architecture. Some examples are given, ranging from conceptual building shapes, through modular wall elements, to abstract geometrical sculptures.

Virtual Archaeology Review

With the rise of available computing capabilities, structural analysis has recently become a key tool for building assessment usually managed by art historians, curators, and other specialist related to the study and preservation of ancient buildings. On the other hand, the flourishing field of procedural modeling has provided some exciting breakthroughs for the recreation of lost buildings and urban structures. However, there is a surprising lack of literature to enable the production of procedural-based buildings taking into account structural analysis, which has proven to be a crucial element for the recreation of faithful masonry structures. In order to perform an in-depth study of the advances in this type of analysis for cultural heritage buildings, we performed a study focused on procedural modeling that make use of structural analysis methods, especially in its application to historic masonry buildings such as churches and cathedrals. Moreover, with the aim of improving the knowledge about structural analysis of procedurally-recreated historical buildings, we have taken a geometric structure, added a set of procedural walls structured in masonry bricks, and studied its behavior in a generic, freely-available simulation tool, thus showing the feasibility of its analysis with nonspecialized tools. This not only has allowed us to understand and learn how the different parameter values of a masonry structure can affect the results of the simulation, but also has proven that this kind of simulations can be easily integrated in an off-the-shelf procedural modeling tool, enabling this kind of analysis for a wide variety of historical studies, or restoration and preservation actions.