X-Git-Url: http://git.lukelau.me/?p=opengl.git;a=blobdiff_plain;f=pbrfrag.glsl;h=d4c7eceb7e26cbb97e529768c50ce9a1469454ef;hp=4421b99b6021a9e6a7da4953122bebf30bbf2499;hb=5e2b8438a1600a790dc105d25b7d5cd2278864aa;hpb=a03f2bc751bbd7f91cbc2f52d2f0f6e753d6f776

diff --git a/pbrfrag.glsl b/pbrfrag.glsl
index 4421b99..d4c7ece 100644
--- a/pbrfrag.glsl
+++ b/pbrfrag.glsl
@@ -7,16 +7,24 @@ in vec2 texCoords;
 
 uniform vec3 camPos;
 
-uniform sampler2D albedoMap;
-uniform sampler2D normalMap;
-uniform sampler2D metallicMap;
-uniform sampler2D roughnessMap;
-uniform sampler2D aoMap;
+struct Material {
+	sampler2D albedoMap;
+	sampler2D normalMap;
+	sampler2D metallicRoughnessMap;
+	sampler2D aoMap;
+	bool hasAlbedo, hasNormal, hasMetallicRoughness, hasAo;
+};
+uniform Material mat;
+
+uniform samplerCube irradianceMap;
+uniform samplerCube prefilterMap;
+uniform sampler2D brdfMap;
 
 out vec4 fragColor;
 
-uniform vec3 lightPositions[4];
-uniform vec3 lightColors[4];
+uniform int numLights;
+uniform vec3 lightPositions[8];
+uniform vec3 lightColors[8];
 
 const float PI = 3.14159265359;
 
@@ -24,6 +32,10 @@ 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);
@@ -45,7 +57,9 @@ float geometrySmith(vec3 N, vec3 V, vec3 L, float roughness) {
 }
 
 vec3 getNormalFromMap() {
-	vec3 tangentNormal = texture(normalMap, texCoords).xyz * 2.f - 1.f;
+	vec3 tangentNormal = vec3(0, 0, 1);
+	if (mat.hasNormal)
+		tangentNormal = texture(mat.normalMap, texCoords).xyz * 2.f - 1.f;
 	vec3 Q1 = dFdx(worldPos);
     vec3 Q2 = dFdy(worldPos);
     vec2 st1 = dFdx(texCoords);
@@ -60,20 +74,29 @@ vec3 getNormalFromMap() {
 }
 
 void main() {
-	vec3 albedo = pow(texture(albedoMap, texCoords).rgb, vec3(2.2));
+	vec3 albedo = vec3(1);
+	if (mat.hasAlbedo)
+		albedo = pow(texture(mat.albedoMap, texCoords).rgb, vec3(2.2));
+
 	vec3 normal = getNormalFromMap();
-	float metallic = texture(metallicMap, texCoords).r;
-	float roughness = texture(roughnessMap, texCoords).r;
-	float ao = texture(aoMap, texCoords).r;
+
+	float metallic = 0, roughness = 1;
+	if (mat.hasMetallicRoughness) {
+		metallic = texture(mat.metallicRoughnessMap, texCoords).b;
+		roughness = texture(mat.metallicRoughnessMap, texCoords).g;
+	}
+	float ao = mat.hasAo ? texture(mat.aoMap, texCoords).r : 1;
 
 	vec3 N = normalize(normal);
 	vec3 V = normalize(camPos - worldPos);
 
 	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++) {
+	for (int i = 0; i < numLights; i++) {
 		vec3 L = normalize(lightPositions[i] - worldPos);
 		vec3 H = normalize(V + L);
 
@@ -97,7 +120,20 @@ 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