Add specular component

[opengl.git] / pbrfrag.glsl

diff --git a/pbrfrag.glsl b/pbrfrag.glsl
index 4421b99b6021a9e6a7da4953122bebf30bbf2499..99523ec604f99b0fd7673e56848d14a837328c13 100644 (file)
--- a/pbrfrag.glsl
+++ b/pbrfrag.glsl
@@ -12,6 +12,9 @@ uniform sampler2D normalMap;
 uniform sampler2D metallicMap;
 uniform sampler2D roughnessMap;
 uniform sampler2D aoMap;
+uniform samplerCube irradianceMap;
+uniform samplerCube prefilterMap;
+uniform sampler2D brdfMap;
 
 out vec4 fragColor;
 
@@ -24,6 +27,10 @@ vec3 fresnelSchlick(float cosTheta, vec3 F0) {
        return F0 + (1.f - F0) * pow(1.f - cosTheta, 5.f);
 }
 
+vec3 fresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness) {
+       return F0 + (max(vec3(1.f - roughness), F0) - F0) * pow(1.f - cosTheta, 5.f);
+}
+
 float distributionGGX(vec3 N, vec3 H, float roughness) {
        float a = roughness * roughness;
        float NdotH = mdot(N, H);
@@ -71,6 +78,8 @@ void main() {
 
        vec3 F0 = mix(vec3(0.04), albedo, metallic);
 
+       vec3 R = reflect(-V, N);
+
        // reflectance
        vec3 Lo = vec3(0.f);
        for (int i = 0; i < lightPositions.length(); i++) {
@@ -97,7 +106,20 @@ void main() {
                Lo += (kD * albedo / PI + specular) * radiance * mdot(N, L);
        }
 
-       vec3 ambient = vec3(0.03) * albedo * ao;
+       vec3 F = fresnelSchlickRoughness(mdot(N, V), F0, roughness);
+       
+       vec3 kS = F;
+       vec3 kD = (1.f - kS) * (1.f - metallic);
+
+       vec3 irradiance = texture(irradianceMap, N).rgb;
+       vec3 diffuse = irradiance * albedo;
+
+       const float maxReflectionLoD = 4.f;
+       vec3 prefilteredColor = textureLod(prefilterMap, R, roughness * maxReflectionLoD).rgb;
+       vec2 envBRDF = texture(brdfMap, vec2(mdot(N, V), roughness)).rg;
+       vec3 specular = prefilteredColor * (F * envBRDF.x + envBRDF.y);
+
+       vec3 ambient = (kD * diffuse + specular) * ao;
        vec3 color = ambient + Lo;
 
        color = color / (color + vec3(1.f)); // map to HDR