The use of virtual environments for percentage view analysis Damian Schofield a, * , Christopher J.B. Cox b a School of Computer Science and Information Technology, University of Nottingham, Jubilee Campus, Wollaton Road, Nottingham NG8 1BB, UK b School of Chemical, Environmental and Mining Engineering, University of Nottingham, University Park Nottingham, NG7 2RD, UK Received 5 April 2005 Abstract It is recognised that Visual Impact Assessment (VIA), unlike many other aspects of Environmental Impact Assessments (EIA), relies less upon measurement than upon experience and judgement. Hence, it is necessary for a more structured and consistent approach towards VIA, reducing the amount of bias and subjectivity. For proposed developments, there are very few quantitative techniques for the evaluation of visibility, and these existing methods can be highly inaccurate and time consuming. Percentage view changes are one of the few quantitative techniques, and the use of computer technology can reduce the inaccuracy and the time spent evaluating the visibility of either existing or proposed developments. For over 10 years, research work undertaken by the authors at the University of Nottingham has employed Computer Graphics (CG) and Virtual Reality (VR) in civilian and industrial contexts for environmental planning, design visualisation, accident reconstruction, risk analysis, data visualisation and training simulators. This paper describes a method to quantitatively assess the visual impact of proposed developments on the landscape using CG techniques. This method allows the determination of accurate percentage view changes with the use of a computer-generated model of the environment and the application of specialist software that has been developed at the University of Nottingham. The principles are easy to understand and therefore planners, authorisation agencies and members of the public can use and understand the results. A case study is shown to demonstrate the application and the capabilities of the technology. q 2005 Elsevier Ltd. All rights reserved. Keywords: Visual impact assessment; Computer graphics; Virtual reality; Percentage view change 1. Introduction Assessing the impact of a proposed development on the landscape is often known as Visual Impact Assessment (VIA). Unlike many other aspects of Environmental Impact Assessments (EIAs), VIA’s often rely less upon measure- ment than upon experience and judgement (Institute of Environmental Assessment and The Landscape Institute, 1995). Visual impacts can be defined as the changes in appearance of the landscape as a result of developments and they can be positive (an improvement) or negative (a detraction), direct or indirect, temporary or permanent, single or cumulative and can vary in magnitude and significance. Pullar and Tidey (2001) define VIA as: “The formal process used to evaluate the visual merits of a proposed development with respect to passive human interaction.” In the UK, visual impacts have been a part of development control for eighty years, and they became national in scope in 1947. Pullar and Tidey (2001) state that there are only a few quantitative methodologies for visual impact analysis. Hence, a structured and consistent approach towards VIA would be beneficial, reducing the amount of bias and subjectivity. This paper will discuss the use of Computer Graphics (CG) to create Three-Dimensional (3D) models of existing and proposed environments in order to produce visualisa- tions from critical viewpoints, animations, photomontages and Fields of Visual Influence (FVIs). A method for percentage view change calculation will be introduced, this allows the accurate determination of the visual difference caused by a proposed development by the use of a computer generated 3D model of the surrounding Journal of Environmental Management 76 (2005) 342–354 www.elsevier.com/locate/jenvman 0301-4797/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.jenvman.2005.01.021 * Corresponding author. Tel.: C44 115 9514084; fax: C44 115 9514115. E-mail address: damian.schofield@nottingham.ac.uk (D. Schofield).