#version 120 //Upper & lower parts of the sky varying vec4 color; void main() { gl_FragData[0] = color; gl_FragData[0].rgb = mix(gl_FragData[0].rgb, gl_Fog.color.rgb, clamp((gl_FogFragCoord - gl_Fog.start) * gl_Fog.scale, 0.0, 1.0)); }