Alternative Diffuse Lighting and Specular Reflection Approach Using YIQ Color Space for 3D Scene Visualization Using Programmable HLSL Shaders

Abstract

In this work an alternative approach for diffuse lighting and specular reflections is presented that uses YIQ color spaceinstead of traditional RGB color space. The classical illumination algorithms that rely on RGB color space may lead tounrealistic results either due to the fact that they cannot make the original color brighter (inherent limitation imposedby using the RGB color space) or produce incorrect shades when viewed from certain angles because in thecalculation of the specular reflection the original texture color is not taken into account.The approach proposed in this work gets around the problem by applying illumination in YIQ color space using its“luma” component (Y). In this novel approach the diffuse lighting is capable of increasing the perceived brightness ofthe source texture and the resulting color is always dependant on the surface’s texture and produces reasonablyrealistic results when viewed from any possible angle. The algorithm and its HLSL shader code are described in thiswork along with the experiments that illustrate the problem and the solution. The performance benchmarks are alsoprovided, showing that the proposed approach is a viable and realistic solution for applications running in real-time.