155 lines
4.0 KiB
GLSL
155 lines
4.0 KiB
GLSL
#version 460 core
|
|
|
|
out vec4 FragColor;
|
|
in vec2 TexCoords;
|
|
in vec3 WorldPos;
|
|
in vec3 Normal;
|
|
|
|
uniform vec3 camPos;
|
|
|
|
uniform sampler2D albedoMap;
|
|
uniform sampler2D metallicMap;
|
|
uniform sampler2D normalMap;
|
|
uniform sampler2D roughnessMap;
|
|
uniform sampler2D aoMap;
|
|
|
|
|
|
uniform samplerCube irradianceMap;
|
|
uniform samplerCube prefilterMap;
|
|
uniform sampler2D brdfLUT;
|
|
|
|
uniform vec3 lightPositions[4];
|
|
uniform vec3 lightColors[4];
|
|
|
|
const float PI = 3.14159265359;
|
|
|
|
|
|
|
|
// ratio Refraction vs Reflection (F function)
|
|
vec3 fresnelSchlick (float cosTheta, vec3 F0, float roughness)
|
|
{
|
|
return F0 + (max(vec3(1.0- roughness), F0)- F0) * pow(clamp(1.0 - cosTheta, 0.0, 1.0), 5.0);
|
|
}
|
|
|
|
// Calculate Normal distribution (D function)
|
|
float DistributionGGX(vec3 N , vec3 H, float roughness){
|
|
float a = roughness*roughness;
|
|
float a2 = a*a;
|
|
float NdotH = max(dot(N, H), 0.0);
|
|
float NdotH2 = NdotH * NdotH;
|
|
|
|
float num = a2;
|
|
float denom = (NdotH2 * ( a2 - 1.0) + 1.0);
|
|
denom = PI * denom * denom;
|
|
return num / denom;
|
|
}
|
|
|
|
// G function
|
|
float GeometrySchlickGGX(float NdotV, float roughness){
|
|
float r = (roughness + 1.0);
|
|
float k = (r*r) / 8.0;
|
|
|
|
float num = NdotV;
|
|
float denom = NdotV * (1.0 - k) + k;
|
|
|
|
return num / denom;
|
|
}
|
|
|
|
float GeometrySmith(vec3 N, vec3 V, vec3 L, float roughness)
|
|
{
|
|
float NdotV = max(dot(N, V), 0.0);
|
|
float NdotL = max(dot(N,L), 0.0);
|
|
float ggx2 = GeometrySchlickGGX(NdotV, roughness);
|
|
float ggx1 = GeometrySchlickGGX(NdotL, roughness);
|
|
|
|
return ggx1 * ggx2;
|
|
}
|
|
|
|
vec3 getNormalFromNormalMap(){
|
|
vec3 tangentNormal = texture(normalMap, TexCoords).xyz * 2.0 - 1.0;
|
|
|
|
vec3 Q1 = dFdx(WorldPos);
|
|
vec3 Q2 = dFdy(WorldPos);
|
|
vec2 st1 = dFdx(TexCoords);
|
|
vec2 st2 = dFdy(TexCoords);
|
|
|
|
vec3 N = normalize(Normal);
|
|
vec3 T = normalize(Q1 *st2.t - Q2*st1.t);
|
|
vec3 B = -normalize(cross(N, T));
|
|
mat3 TBN = mat3(T, B, N);
|
|
|
|
return normalize(TBN * tangentNormal);
|
|
}
|
|
|
|
|
|
|
|
void main(){
|
|
|
|
vec3 albedo = pow(texture(albedoMap, TexCoords).rgb, vec3(2.2));
|
|
float metallic = texture(metallicMap, TexCoords).r;
|
|
float roughness = texture(roughnessMap, TexCoords).r;
|
|
float ao = texture(aoMap, TexCoords).r;
|
|
|
|
|
|
vec3 N = getNormalFromNormalMap();
|
|
vec3 V = normalize(camPos - WorldPos);
|
|
vec3 R = reflect(-V, N);
|
|
|
|
|
|
vec3 F0 = vec3(0.04);
|
|
F0 = mix(F0, albedo, metallic);
|
|
|
|
// Calculate the light contributions of each light source
|
|
vec3 Lo = vec3(0.0);
|
|
for( int i = 0; i < 4; ++i)
|
|
{
|
|
vec3 L = normalize(lightPositions[i] - WorldPos);
|
|
vec3 H = normalize(V + L);
|
|
float distance = length(lightPositions[i] - WorldPos);
|
|
float attenuation = 1.0/ (distance*distance);
|
|
vec3 radiance = lightColors[i] * attenuation;
|
|
|
|
float NDF = DistributionGGX(N,H, roughness);
|
|
float G = GeometrySmith(N,V,L, roughness);
|
|
vec3 F = fresnelSchlick(max(dot(H,V), 0.0), F0, roughness);
|
|
|
|
vec3 kS = F;
|
|
vec3 kD = vec3(1.0) - kS;
|
|
kD *= 1.0 - metallic;
|
|
|
|
|
|
vec3 numerator = NDF * G * F;
|
|
float denominator = 4.0 * max(dot(N,V), 0.0) * max(dot(N, L), 0.0) + 0.0001;
|
|
vec3 specular = numerator /denominator;
|
|
|
|
|
|
float NdotL = max(dot(N,L), 0.0);
|
|
Lo += (kD * albedo / PI + specular) * radiance * NdotL;
|
|
}
|
|
|
|
|
|
|
|
// Calculate the ambient term and add it
|
|
vec3 kS = fresnelSchlick(max(dot(N,V), 0.0), F0, roughness);
|
|
vec3 kD = 1.0 - kS;
|
|
kD *= 1.0 - metallic;
|
|
vec3 irradiance = texture(irradianceMap, N).rgb;
|
|
vec3 diffuse = irradiance* albedo;
|
|
|
|
const float MAX_REFLECTION_LOD = 4.0;
|
|
vec3 prefilterColor = textureLod(prefilterMap, R, roughness * MAX_REFLECTION_LOD).rgb;
|
|
vec2 envBRDF = texture(brdfLUT, vec2(max(dot(N,V), 0.0), roughness)).rg;
|
|
vec3 specular = prefilterColor * (kS * envBRDF.x + envBRDF.y);
|
|
|
|
|
|
|
|
vec3 ambient = (kD * diffuse + specular) * ao;
|
|
vec3 color = ambient + Lo;
|
|
|
|
// HDR tonemapping
|
|
color = color / (color + vec3(1.0));
|
|
// gamma correct
|
|
color = pow(color, vec3(1.0/2.2));
|
|
|
|
FragColor = vec4(color, 1.0);
|
|
} |