How to Convert Reality into Virtual Reality: Exploring Colour Appearance in Digital Models

Licentiate thesis, 2006

Today, the different actors in the design process have communication difficulties for visualizing and predicting how the not yet built environment is going to be experienced. Realistic virtual environments could make it easier for architects, users and clients to participate in the planning process. The Virtual Reality (VR) research of today has different focuses, concerning both visualization and interaction. Few studies concern colour appearance in virtual compared to real rooms. This licentiate thesis deals with the problems of translating reality into its digital counterparts, focusing on colour appearance. The main aim is to identify problems of making realistic models in VR. A following aim is to discuss chosen solutions for increased realism. Problems connected to visual appearance and interactivity in the model and technological aspects in the software are considered. Different approaches are used: (1) a literature review including research on colour appearance, VR, and light calculation in computer graphics, (2) a comparison between existing studies on colour appearance in 2D vs 3D, (3) a comparison between a real room and different VR simulations and (4) an elaboration with an algorithm. The studies pointed out the significance of interreflections, colour variations, perceived colour of light and shadowing for the visual appearance in real rooms. The results showed various problems related to the translation and comparison of reality to VR. There were some distinct differences between the real and the virtual rooms. Some differences had to do with the arbitrary parameter settings in the software; heavily simplified chromatic information on the illumination and incorrect interreflections. Concerning interactivity, the models were experienced differently depending on the application. It therefore seems important to consider the purpose of the model when deciding which media to use when displaying it. Current research is primarily concerned with rendered images and needs to be taken one step further. This licentiate thesis forms a base for future studies. The full development of this type of research is still a distant future goal, but it could be looked upon as a logical next step in the technological progress.