The present invention provides methods, apparatus and systems for enabling real-time lighting of 3D geometric models. While these are well-suited for all processors, these are particularly useful on low power processors typically found in PDAs, cell phones, and embedded display systems. Methods+presented utilize a preprocessing scale factor and real-time shift factor to efficiently calculate diffuse lighting intensities for the bound vertices of the geometric model. An example embodiment includes scaling first digitized data of a 3D model in a floating point datatype by a scaling factor to form scaled digitized data. The scaling factor being a proper power of two. Converting said scaled digitized data into an integer datatype forming second digitized data. Enabling a transfer of said second digitized data to a display system, and facilitating lighting and shading said second format of digitized data.