162 lines
No EOL
4.4 KiB
GLSL
162 lines
No EOL
4.4 KiB
GLSL
#version 450
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layout (location = 0) in vec3 inWorldPos;
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layout (location = 1) in vec3 inNormal;
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layout (location = 2) in vec2 inUV;
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layout (binding = 0) uniform UBO {
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mat4 projection;
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mat4 model;
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mat4 view;
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vec3 camPos;
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} ubo;
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layout (binding = 1) uniform UBOParams {
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vec4 lights[4];
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float exposure;
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float gamma;
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} uboParams;
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layout(push_constant) uniform PushConsts {
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layout(offset = 12) float roughness;
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layout(offset = 16) float metallic;
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layout(offset = 20) float specular;
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layout(offset = 24) float r;
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layout(offset = 28) float g;
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layout(offset = 32) float b;
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} material;
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layout (binding = 2) uniform samplerCube samplerIrradiance;
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layout (binding = 3) uniform sampler2D samplerBRDFLUT;
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layout (binding = 4) uniform samplerCube prefilteredMap;
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layout (location = 0) out vec4 outColor;
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#define PI 3.1415926535897932384626433832795
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#define ALBEDO vec3(material.r, material.g, material.b)
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// From http://filmicgames.com/archives/75
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vec3 Uncharted2Tonemap(vec3 x)
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{
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float A = 0.15;
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float B = 0.50;
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float C = 0.10;
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float D = 0.20;
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float E = 0.02;
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float F = 0.30;
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return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;
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}
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// Normal Distribution function --------------------------------------
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float D_GGX(float dotNH, float roughness)
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{
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float alpha = roughness * roughness;
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float alpha2 = alpha * alpha;
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float denom = dotNH * dotNH * (alpha2 - 1.0) + 1.0;
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return (alpha2)/(PI * denom*denom);
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}
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// Geometric Shadowing function --------------------------------------
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float G_SchlicksmithGGX(float dotNL, float dotNV, float roughness)
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{
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float r = (roughness + 1.0);
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float k = (r*r) / 8.0;
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float GL = dotNL / (dotNL * (1.0 - k) + k);
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float GV = dotNV / (dotNV * (1.0 - k) + k);
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return GL * GV;
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}
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// Fresnel function ----------------------------------------------------
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vec3 F_Schlick(float cosTheta, vec3 F0)
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{
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return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
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}
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vec3 F_SchlickR(float cosTheta, vec3 F0, float roughness)
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{
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return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(1.0 - cosTheta, 5.0);
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}
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vec3 prefilteredReflection(vec3 R, float roughness)
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{
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const float MAX_REFLECTION_LOD = 9.0; // todo: param/const
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float lod = roughness * MAX_REFLECTION_LOD;
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float lodf = floor(lod);
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float lodc = ceil(lod);
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vec3 a = textureLod(prefilteredMap, R, lodf).rgb;
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vec3 b = textureLod(prefilteredMap, R, lodc).rgb;
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return mix(a, b, lod - lodf);
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}
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vec3 specularContribution(vec3 L, vec3 V, vec3 N, vec3 F0, float metallic, float roughness)
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{
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// Precalculate vectors and dot products
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vec3 H = normalize (V + L);
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float dotNH = clamp(dot(N, H), 0.0, 1.0);
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float dotNV = clamp(dot(N, V), 0.0, 1.0);
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float dotNL = clamp(dot(N, L), 0.0, 1.0);
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// Light color fixed
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vec3 lightColor = vec3(1.0);
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vec3 color = vec3(0.0);
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if (dotNL > 0.0) {
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// D = Normal distribution (Distribution of the microfacets)
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float D = D_GGX(dotNH, roughness);
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// G = Geometric shadowing term (Microfacets shadowing)
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float G = G_SchlicksmithGGX(dotNL, dotNV, roughness);
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// F = Fresnel factor (Reflectance depending on angle of incidence)
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vec3 F = F_Schlick(dotNV, F0);
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vec3 spec = D * F * G / (4.0 * dotNL * dotNV + 0.001);
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vec3 kD = (vec3(1.0) - F) * (1.0 - metallic);
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color += (kD * ALBEDO / PI + spec) * dotNL;
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}
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return color;
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}
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void main()
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{
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vec3 N = normalize(inNormal);
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vec3 V = normalize(ubo.camPos - inWorldPos);
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vec3 R = reflect(-V, N);
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float metallic = material.metallic;
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float roughness = material.roughness;
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vec3 F0 = vec3(0.04);
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F0 = mix(F0, ALBEDO, metallic);
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vec3 Lo = vec3(0.0);
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for(int i = 0; i < uboParams.lights.length(); i++) {
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vec3 L = normalize(uboParams.lights[i].xyz - inWorldPos);
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Lo += specularContribution(L, V, N, F0, metallic, roughness);
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}
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vec2 brdf = texture(samplerBRDFLUT, vec2(max(dot(N, V), 0.0), roughness)).rg;
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vec3 reflection = prefilteredReflection(R, roughness).rgb;
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vec3 irradiance = texture(samplerIrradiance, N).rgb;
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// Diffuse based on irradiance
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vec3 diffuse = irradiance * ALBEDO;
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vec3 F = F_SchlickR(max(dot(N, V), 0.0), F0, roughness);
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// Specular reflectance
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vec3 specular = reflection * (F * brdf.x + brdf.y);
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// Ambient part
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vec3 kD = 1.0 - F;
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kD *= 1.0 - metallic;
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vec3 ambient = (kD * diffuse + specular);
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vec3 color = ambient + Lo;
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// Tone mapping
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color = Uncharted2Tonemap(color * uboParams.exposure);
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color = color * (1.0f / Uncharted2Tonemap(vec3(11.2f)));
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// Gamma correction
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color = pow(color, vec3(1.0f / uboParams.gamma));
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outColor = vec4(color, 1.0);
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} |