A robust shading scheme using continuous-domain modelling of specular reflection

In computer graphics, curved surfaces of 3-dimensional objects are often represented by a mesh of planar triangular patches. These planar patches are shaded using either Gouraud or Phong shading. Phong shading is computationally more expensive but gives a realistic rendering of reflective objects. An efficient approach should apply Phong shading to only those triangular patches where reflection of light source is visible; simpler Gouraud shading should applied to all other patches. In this paper, we propose a new scheme, based on continuous-domain modeling of specular reflection, that determines if the simpler Gouraud shading could be used instead of computationally expensive Phong shading. This new scheme is very robust, takes care of a wide range of reflection coefficients, and has a fixed computational cost.