glDisableGLLIGHTING

glDisableGLLIGHTING is a function in the OpenGL graphics API that disables the fixed-function lighting subsystem. When lighting is enabled, OpenGL calculates the illumination of surfaces based on properties like material color, light source position and color, and surface normals. This process simulates how light interacts with objects in a 3D scene, creating realistic shading and highlights.

Calling glDisableGLLIGHTING effectively turns off this lighting calculation. As a result, surfaces will no longer be affected by any configured lights. Instead, they will be rendered using their base colors or textures without any shading or highlights derived from the lighting model. This can be useful for various purposes, such as rendering unlit objects, debugging lighting issues, or achieving specific artistic effects.

To re-enable lighting after it has been disabled, the corresponding function glEnableGLLIGHTING would be used. The fixed-function lighting pipeline, which glDisableGLLIGHTING affects, has largely been superseded by programmable shaders in modern OpenGL development. However, understanding functions like glDisableGLLIGHTING is still relevant for working with older OpenGL codebases or for educational purposes when learning the fundamentals of 3D graphics rendering.