OpenGLShader实现物件材料效果详解

void main() {
    vec2 uv = gl_FraGCoord.xy / iResolution.xy;
    vec4 texture1 = texture(iChannel1,uv);
    vec4 texture2 = texture(iChannel2,uv);
    vec3 rgb = texture1.rgb + texture2.rgb;
    vec4 pixel = vec4(rgb,1.);
    gl_FragColor = pixel;
}

void main()
{
    vec2 uv1 =  gl_FragCoord.xy / iResolution.xy;
    uv1.y = mod(uv1.y, 1.0);
    vec2 uv2 = uv1;

    uv1 -= 0.5;
    uv1 *= 2.;
    uv1 += 0.5;

    uv2 -= 0.5;
    uv2 *= 1.5;
    uv2 += 0.5;

    float l = 0.003;

    float k = smoothstep((1.0 - l), (1.0 - l) + 0.006, uv1.x);
    float k1 = smoothstep(l, l - 0.006, uv1.x);

    float m = smoothstep((1.0 - l), (1.0 - l) + 0.006, uv1.y);
    float m1 = smoothstep(l, l - 0.006, uv1.y);
    

    float i = smoothstep((1.0 - l), (1.0 - l) + 0.006, uv2.x);
    float i1 = smoothstep(l, l - 0.006, uv2.x);

    float j = smoothstep((1.0 - l), (1.0 - l) + 0.006, uv2.y);
    float j1 = smoothstep(l, l - 0.006, uv2.y);

    vec4 texture1 = texture(iChannel1, uv1)* (1.0 - k) * (1.0 - k1) * (1.0 - m) * (1.0 - m1);
    vec4 texture2 = texture(iChannel3, vec2(uv2.x,uv2.y)) * (1.0 - i) * (1.0 - i1) * (1.0 - j) * (1.0 - j1);
    gl_FragColor = 1.0 - (1.0 - texture1) * (1.0 - texture2);
}