Perturbed Brush for Watercolor Painting


 To generate a 3DCG image natural and familiar to human, we propose a method to generate a water color-like painting with out-of-edge brush expression referring to the method of Niehaus, et al. based on G-buffer.  We multiply the texel value of the noise texture shown in the picture on the right, and the adjusting matrix (scaling matrix), and add the value to the original sampling position to make new sampling position, and re-sample the position. In this process, we use the noise that feathers the hatching pattern, where Nienhouse et al. use Perlin noise. Further, we use the 2x2 adjusting matrix (scaling matrix) and fix the value considering the direction of the brush movement. Out-of-edge like painting becomes possible from these processes.