In this work, I develop an approach to include Global Illumination (GI) effects in non-photorealistic real-time rendering; real-time rendering is one of the main areas of focus in the gaming industry and the booming virtual reality(VR) and augmented reality(AR) industries. My approach is based on adapting the Barycentric shader to create a wide variety of painting effects. This shader helps achieve the look of a 2D painting in an interactively rendered 3D scene. The shader accommodates robust computation to obtain artistic reflection and refraction. My contributions can be summarized as follows: Development of a generalized Barycentric shader that can provide artistic control, integration of this generalized Barycentric shader into an interactive ray tracer, and interactive rendering of a 3D scene that closely represent the reference painting.