MAM2016: Eurographics Workshop on Material Appearance Modeling

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/2630839

Browse

Browsing MAM2016: Eurographics Workshop on Material Appearance Modeling by Subject "I.3.7 [Computer Graphics]"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Exploring Material Recognition for Estimating Reflectance and Illumination From a Single Image
    (The Eurographics Association, 2016) Weinmann, Michael; Klein, Reinhard; Reinhard Klein and Holly Rushmeier
    In this paper, we propose a novel approach for recovering illumination and reflectance from a single image. Our approach relies on the assumption that the surface geometry has already been reconstructed and a-priori knowledge in form of a database of digital material models is available. The first step of our technique consists in recognizing the respective material in the image using synthesized training data based on the given material database. Subsequently, the illumination conditions are estimated based on the recognized material and the surface geometry. Using this novel strategy we demonstrate that reflectance and illumination can be estimated reliably for several materials that are beyond simple Lambertian surface reflectance behavior because of exhibiting mesoscopic effects such as interreflections and shadows.
  • Thumbnail Image
    Item
    Interactive Appearance Prediction for Cloudy Beverages
    (The Eurographics Association, 2016) Dal Corso, Alessandro; Frisvad, Jeppe Revall; Kjeldsen, Thomas Kim; Bærentzen, Jakob Andreas; Reinhard Klein and Holly Rushmeier
    Juice appearance is important to consumers, so digital juice with a slider that varies a production parameter or changes juice content is useful. It is however challenging to render juice with scattering particles quickly and accurately. As a case study, we create an appearance model that provides the optical properties needed for rendering of unfiltered apple juice. This is a scattering medium that requires volume path tracing as the scattering is too much for single scattering techniques and too little for subsurface scattering techniques. We investigate techniques to provide a progressive interactive appearance prediction tool for this type of medium. Our renderings are validated by qualitative and quantitative comparison with photographs. Visual comparisons using our interactive tool enable us to estimate the apple particle concentration of a photographed apple juice.
  • Thumbnail Image
    Item
    Practical Experiences with Using Autocollimator for Surface Reflectance Measurement
    (The Eurographics Association, 2016) Havran, Vlastimil; Reinhard Klein and Holly Rushmeier
    We present our experiences with using an autocollimator to set up the surface reflectance measurement for both BRDF and BTF. Assuming the measured material appearance is put on a locally flat surface, the autocollimator allows us to set the perpendicularity of the measured sample in stationary measurement setups. The principle works also vice versa, we can align the measurement setup against a stationary sample for on-site measurements. The autocollimator requires to use a collimated beam of light, a mirror, a beam splitter, and a detector. We describe the autocollimator principle, problems, and the issues involved when using an autocollimator for surface reflectance measurement setups.
  • Thumbnail Image
    Item
    Weathering of Urban Scenes: Challenges and Possible Solutions
    (The Eurographics Association, 2016) Muñoz-Pandiella, I.; Bosch, C.; Mérillou, N.; Pueyo, X.; Mérillou, S; Patow, G.; Reinhard Klein and Holly Rushmeier
    In this paper, we propose to discuss on one of the main challenges in realistic rendering of urban scenes: changes in appearance over time within a urban context. After studying the previous work on weathering techniques, we have found that there is a lack of estimation for some important environmental parameters (such as sun radiation) that have a wrong impact on weathering phenomena simulation and, thus, on the appearance of virtual objects. We also think that such a problem needs to be addressed on large urban models. Here, we discuss some possible solutions we have studied in our research. These solutions are focused on screen-space techniques, in order to efficiently compute those factors and use them to interactively generate weathering effects.