The light guide plate is the key component in a backlight unit of TFT-LCD, where point or line light source(s) is distributed evenly in two dimensional light guide plate. A light guide plate (LGP) has many refraction and/or scattering optical patterns on its bottom surface to transmit the light toward the display panel. The LGP performance can only be predicted by massive optical calculation of geometrical ray-tracing on the optical patterns. The challenge is to design and modify the parameters of thousands of optical patterns to achieve proper uniformity of the emanated light. An integrated design interface to improve the design efficiency is proposed in this paper. The optical pattern properties are all categorized to provide automatic generation of the 2-D and 3-D models of the optical pattern on LGP for ray-tracing analysis. Without this tool, the design process can be minute and complicated.