#version 300 es uniform sampler2D sTexture; uniform mediump sampler3D sColourLUT; in mediump vec2 texCoords; layout(location = 0) out lowp vec4 oFragColour; void main() { highp vec3 vCol = texture(sTexture, texCoords).rgb; lowp vec3 vAlteredCol = texture(sColourLUT, vCol.rgb).rgb; oFragColour = vec4(vAlteredCol, 1.0); }