Merge pull request #8345 from bhouston/fix_srgb_encoding

fix sRGB encoding, missing constant.

src/renderers/shaders/ShaderChunk/encodings_pars_fragment.glsl

@@ -15,7 +15,7 @@ vec4 sRGBToLinear( in vec4 value ) {
   return vec4( mix( pow( value.rgb * 0.9478672986 + vec3( 0.0521327014 ), vec3( 2.4 ) ), value.rgb * 0.0773993808, vec3( lessThanEqual( value.rgb, vec3( 0.04045 ) ) ) ), value.w );
 }
 vec4 LinearTosRGB( in vec4 value ) {
-  return vec4( mix( pow( value.rgb, vec3( 0.41666 ) ) - vec3( 0.055 ), value.rgb * 12.92, vec3( lessThanEqual( value.rgb, vec3( 0.0031308 ) ) ) ), value.w );
+  return vec4( mix( pow( value.rgb, vec3( 0.41666 ) ) * 1.055 - vec3( 0.055 ), value.rgb * 12.92, vec3( lessThanEqual( value.rgb, vec3( 0.0031308 ) ) ) ), value.w );
 }
 
 vec4 RGBEToLinear( in vec4 value ) {