From c1673e5bc73734d7b8ba6f5fa69b48015c8eccec Mon Sep 17 00:00:00 2001
From: Alexander Gauggel <agauggel@uni-koblenz.de>
Date: Sun, 20 Jun 2021 16:52:15 +0200
Subject: [PATCH] [#82] Add specular cook-torrance
---
.../resources/shaders/shader.frag | 63 +++++++++++++++++--
projects/voxelization/src/main.cpp | 9 ++-
2 files changed, 66 insertions(+), 6 deletions(-)
diff --git a/projects/voxelization/resources/shaders/shader.frag b/projects/voxelization/resources/shaders/shader.frag
index 24f4673b..445caea8 100644
--- a/projects/voxelization/resources/shaders/shader.frag
+++ b/projects/voxelization/resources/shaders/shader.frag
@@ -19,13 +19,50 @@ layout(set=0, binding=0) uniform sunBuffer {
layout(set=0, binding=1) uniform texture2D shadowMap;
layout(set=0, binding=2) uniform sampler shadowMapSampler;
+layout(set=0, binding=3) uniform cameraBuffer {
+ vec3 cameraPos;
+};
+
+const float pi = 3.1415;
+
+vec3 lambertBRDF(vec3 albedo){
+ return albedo / pi;
+}
+
+vec3 fresnelSchlick(float cosTheta, vec3 f0){
+ return f0 + (vec3(1) - f0) * pow(1 - cosTheta, 5);
+}
+
+float GGXDistribution(float r, float NoH){
+ float r2 = r * r;
+ float denom = pi * pow(NoH * NoH * (r2 - 1) + 1, 2);
+ return r2 / max(denom, 0.000001);
+}
+
+float GGXSmithShadowingPart(float r, float cosTheta){
+ float nom = cosTheta * 2;
+ float r2 = r * r;
+ float denom = cosTheta + sqrt(r2 + (1 - r2) * cosTheta * cosTheta);
+ return nom / max(denom, 0.000001);
+}
+
+float GGXSmithShadowing(float r, float NoV, float NoL){
+ return GGXSmithShadowingPart(r, NoV) * GGXSmithShadowingPart(r, NoL);
+}
+
void main() {
vec3 albedoTexel = texture(sampler2D(albedoTexture, textureSampler), passUV).rgb;
vec3 normalTexel = texture(sampler2D(normalTexture, textureSampler), passUV).rgb;
vec3 specularTexel = texture(sampler2D(specularTexture, textureSampler), passUV).rgb;
- vec3 albedo = albedoTexel;
+ float r = specularTexel.g;
+ r *= r; // remapping roughness for perceptual linearity
+
+ float metal = specularTexel.b;
+ vec3 albedo = mix(albedoTexel, vec3(0), metal);
+ vec3 f0_dielectric = vec3(0.04f);
+ vec3 f0 = mix(f0_dielectric, albedo, metal);
vec3 T = normalize(passTangent.xyz);
vec3 N_geo = normalize(passNormal);
@@ -33,9 +70,27 @@ void main() {
mat3 TBN = mat3(T, B, N_geo);
normalTexel = normalTexel * 2 - 1;
- vec3 N = TBN * normalTexel;
- vec3 sun = lightInfo.sunStrength * lightInfo.sunColor * clamp(dot(N, lightInfo.L), 0, 1);
+ vec3 N = TBN * normalTexel;
+ vec3 L = lightInfo.L;
+ vec3 V = normalize(cameraPos - passPos);
+ vec3 H = normalize(L + V);
+
+ float NoH = clamp(dot(N, H), 0, 1);
+ float NoL = clamp(dot(N, L), 0, 1);
+ float NoV = clamp(dot(N, V), 0, 1);
+
+ vec3 F = fresnelSchlick(NoH, f0);
+ float D = GGXDistribution(r, NoH);
+ float G = GGXSmithShadowing(r, NoV, NoL);
+ vec3 specular = (F * D * G) / max(4 * NoV * NoL, 0.000001);
+
+ vec3 sun = lightInfo.sunStrength * lightInfo.sunColor * NoL;
sun *= shadowTest(passPos, lightInfo, shadowMap, shadowMapSampler);
vec3 ambient = vec3(0.05);
- outColor = albedo * (sun + ambient);
+
+ vec3 F_in = fresnelSchlick(NoL, f0);
+ vec3 F_out = fresnelSchlick(NoV, f0);
+ vec3 diffuse = lambertBRDF(albedo) * (1 - F_in) * (1 - F_out);
+
+ outColor = (diffuse + specular) * sun + lambertBRDF(albedo) * ambient;
}
\ No newline at end of file
diff --git a/projects/voxelization/src/main.cpp b/projects/voxelization/src/main.cpp
index 33b6cc20..281faaf1 100644
--- a/projects/voxelization/src/main.cpp
+++ b/projects/voxelization/src/main.cpp
@@ -159,7 +159,7 @@ int main(int argc, const char** argv) {
glm::vec3 direction;
float padding;
glm::vec3 sunColor = glm::vec3(1.f);
- float sunStrength = 8.f;
+ float sunStrength = 15.f;
glm::mat4 lightMatrix;
};
LightInfo lightInfo;
@@ -168,8 +168,12 @@ int main(int argc, const char** argv) {
vkcv::DescriptorSetHandle forwardShadingDescriptorSet =
core.createDescriptorSet({ forwardProgram.getReflectedDescriptors()[0] });
+ vkcv::Buffer<glm::vec3> cameraPosBuffer = core.createBuffer<glm::vec3>(vkcv::BufferType::UNIFORM, 1);
+
vkcv::DescriptorWrites forwardDescriptorWrites;
- forwardDescriptorWrites.uniformBufferWrites = { vkcv::UniformBufferDescriptorWrite(0, lightBuffer.getHandle()) };
+ forwardDescriptorWrites.uniformBufferWrites = {
+ vkcv::UniformBufferDescriptorWrite(0, lightBuffer.getHandle()),
+ vkcv::UniformBufferDescriptorWrite(3, cameraPosBuffer.getHandle()) };
forwardDescriptorWrites.sampledImageWrites = { vkcv::SampledImageDescriptorWrite(1, shadowMap.getHandle()) };
forwardDescriptorWrites.samplerWrites = { vkcv::SamplerDescriptorWrite(2, shadowSampler) };
core.writeDescriptorSet(forwardShadingDescriptorSet, forwardDescriptorWrites);
@@ -393,6 +397,7 @@ int main(int argc, const char** argv) {
start = end;
cameraManager.update(0.000001 * static_cast<double>(deltatime.count()));
+ cameraPosBuffer.fill({ cameraManager.getActiveCamera().getPosition() });
glm::vec2 lightAngleRadian = glm::radians(lightAngles);
lightInfo.direction = glm::normalize(glm::vec3(
--
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