An Illumination Model for Realistic Rendering of Snow Surfaces
Fei Liu · KTH Publication Database DiVA (KTH Royal Institute of Technology) · 2010
In this thesis work, several prominent visual effects of a snow surface under a strong light source, for instance, the sun, have been identified and modeled, which includes glittering, micro shadows and regional translucency due to subsurface light scattering. The glittering effect was implemented using blooming technique which makes candidate pixels’ colours bleed into their neighbours. Normal mapping and horizon map were experimented in attempt to obtain small surface details and micro shadows. In the end, a curvature-based local illumination model was devised instead to soften such a requirement as modeling micro shadows. From this local model, we gained regional light enhancement or suppression as well as a regional translucency effect. The light suppression effect can be considered as a kind of local shadowing effect. A surface point’s mean curvature was employed in this model. All these effects were modeled in such a way that the rendering of them is capable of being carried out on an average machine at an interactive frame rate.