Visual simulation of snowfall, snow cover and snowmelt

Creation of seasonal scenery images by computer graphics is an attractive theme with many problems to be solved. This paper presents a method of expressing snow to create natural scenery image in winter. We describe a method of automatically creating the behavior of snowflakes in a field of air currents with respect to snowfall, a method of automatically creating shapes of snow accumulation by using virtual temperature as a parameter with respect to snow cover formed just after snowfall, and a method based on heat propagation simulation taking into account sunlight, ground heat, and radiation heat from objects with respect to snowmelt. This paper furthermore presents an image creation method to express the feel of the material of snowfall and snow cover.