The paper presents an efficient way of designing lighting setup for rendering 3D face model. Specifically, we focus on obtaining lighting direction for Rembrandt lighting. A Rembrandt patch is a triangle defined as the bright region surrounded by self and cast shadows on a check area, and we use the self- and cast-shadow curves for computing the direction of main lighting. A user graphically specifies a Rembrandt patch on a 3D model. From the user input, lighting directions are estimated from the cast- and self-shadow geometry on a 3D face model. The final lighting direction is decided among the candidates predicted by the self and cast shadows. The presented method lets a user interactively design and achieve Rembrandt lighting by alleviating repetitive manual search for the light direction by trial and error. Experimental results show the effectiveness of the presented method. It suggests appropriate Rembrandt lighting directions quickly and easily.