$input v_texcoord0 #include "terrain_common.sh" void main() { vec2 s = texture2D(u_SmapSampler, v_texcoord0).rg * u_DmapFactor; vec3 n = normalize(vec3(-s, 1)); float d = clamp(n.z, 0.0, 1.0) / 3.14159; vec3 r = vec3(d, d, d); gl_FragColor = vec4(r, 1); }