1. A method of a graphics processing apparatus comprising: sampling a texture value of a first texture layer at an offset to a second texture layer of a surface having at least the first texture layer and the second texture layer mapped thereto; adjusting pixel color for a pixel of the second texture layer using the texture value; and determining a background pixel color as a sum of a background texture color and a specular component, the specular component multiplied by an alpha component at a coordinate determined by the offset, and the sum multiplied by a product of a diffuse component and the alpha component at the coordinate determined by the offset.