Irradiance Map

.gitattributes

@@ -2,3 +2,4 @@
 *.mtl filter=lfs diff=lfs merge=lfs -text
 *.jpg filter=lfs diff=lfs merge=lfs -text
 *.png filter=lfs diff=lfs merge=lfs -text
+*.hdr filter=lfs diff=lfs merge=lfs -text

Shaders/HDRMap.fs

@@ -0,0 +1,22 @@
+#version 460 core
+out vec4 FragColor;
+in vec3 localPos;
+
+uniform sampler2D equirectangularMap;
+
+const vec2 invAtan = vec2(0.1591, 0.3183);
+
+vec2 SampleSphericalMap(vec3 v)
+{
+    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+    uv *= invAtan;
+    uv += 0.5;
+    return uv;
+}
+
+void main(){
+    vec2 uv = SampleSphericalMap(localPos);
+    vec3 color = texture(equirectangularMap, uv).rgb;
+
+    FragColor = vec4(color,1.0);
+}

Shaders/HDRMap.vs

@@ -0,0 +1,12 @@
+#version 460 core
+layout (location = 0) in vec3 aPos;
+
+out vec3 localPos;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+void main(){
+    localPos = aPos;
+    gl_Position = projection * view * vec4(localPos, 1.0);
+}

Shaders/HDRSkybox.fs

@@ -0,0 +1,16 @@
+#version 460 core
+out vec4 FragColor;
+
+in vec3 localPos;
+
+uniform samplerCube environmentMap;
+
+void main(){
+    vec3 envColor = texture(environmentMap, localPos).rgb;
+
+    envColor = envColor /(envColor + vec3(1.0));
+    envColor = pow(envColor, vec3(1.0/2.2));
+
+    FragColor = vec4(envColor,1.0);
+
+}

Shaders/HDRSkybox.vs

@@ -0,0 +1,16 @@
+#version 460 core
+layout (location = 0) in vec3 aPos;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+out vec3 localPos;
+
+void main(){
+    localPos = aPos;
+
+    mat4 rotView = mat4(mat3(view));
+    vec4 clipPos = projection * rotView * vec4(localPos,1.0);
+
+    gl_Position = clipPos.xyww;
+}

Shaders/irradienceconv.fs

@@ -0,0 +1,35 @@
+#version 460 core
+out vec4 FragColor;
+in vec3 localPos;
+
+uniform samplerCube environmentMap;
+
+const float PI = 3.14159265359;
+
+void main(){
+    vec3 normal = normalize(localPos);
+
+    vec3 irradiance = vec3(0.0);
+
+    vec3 up = vec3(0.0, 1.0, 0.0);
+    vec3 right = normalize(cross(up, normal));
+    up = normalize(cross(normal, right));
+
+    float sampleDelta = 0.025;
+    float nrSamples = 0.0;
+
+    for(float phi = 0.0; phi < 2.0 * PI; phi += sampleDelta){
+        for(float theta = 0.0; theta < 0.5 * PI; theta += sampleDelta){
+            // spherical to cartesian
+            vec3 tangentSample = vec3(sin(theta) * cos(phi), sin(theta) * sin(phi), cos(theta));
+            // tangent space to world
+            vec3 sampleVec = tangentSample.x * right + tangentSample.y * up + tangentSample.z * normal;
+
+
+            irradiance += texture(environmentMap, sampleVec).rgb * cos(theta) * sin(theta);
+            nrSamples++;
+        }
+    }
+    irradiance = PI * irradiance * (1.0 / float(nrSamples));
+    FragColor = vec4(irradiance,1.0);
+}

Shaders/pbr.fs

@@ -12,6 +12,8 @@ uniform sampler2D metallicMap;
 uniform sampler2D normalMap;
 uniform sampler2D roughnessMap;
 uniform sampler2D aoMap;
+uniform samplerCube irradianceMap;
+
 
 uniform vec3 lightPositions[4];
 uniform vec3 lightColors[4];
@@ -21,9 +23,9 @@ const float PI = 3.14159265359;
 
 
 // ratio Refraction vs Reflection (F function)
-vec3 fresnelSchlick (float cosTheta, vec3 F0)
+vec3 fresnelSchlick (float cosTheta, vec3 F0, float roughness)
 {
-    return F0 + (1.0 - F0) * pow(clamp(1.0 - cosTheta, 0.0, 1.0), 5.0);
+    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)
@@ -102,7 +104,7 @@ void main(){
         
         float NDF = DistributionGGX(N,H, roughness);
         float G = GeometrySmith(N,V,L, roughness);
-        vec3 F = fresnelSchlick(max(dot(H,V), 0.0), F0);
+        vec3 F = fresnelSchlick(max(dot(H,V), 0.0), F0, roughness);
 
         vec3 kS = F;
         vec3 kD = vec3(1.0) - kS;
@@ -118,8 +120,15 @@ void main(){
         Lo += (kD * albedo / PI + specular) * radiance * NdotL;
     }
 
+    
+
     // Calculate the ambient term and add it 
-    vec3 ambient = vec3(0.03) * albedo * ao;
+    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;
+    vec3 ambient = (kD * diffuse) * ao;
     vec3 color = ambient + Lo;
 
     // HDR tonemapping

Shaders/skybox2.vs

@@ -0,0 +1,13 @@
+#version 460 core
+layout (location = 0) in vec3 aPos;
+
+out vec3 localPos;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+void main()
+{
+    localPos = aPos;
+    gl_Position = projection * view * vec4(localPos ,1.0);
+}

src/Primitives/Skybox.cpp

@@ -17,6 +17,7 @@ void Skybox::Destroy() {
     std::cout << "Skybox destroyed!" << std::endl;
 }
 
+
 void Skybox::loadCubeTextures(const std::vector<std::string>& texture_faces)
 {
     glGenTextures(1, &id);

src/Primitives/texture.h

@@ -9,4 +9,5 @@ struct Texture{
    std::string path;
 };
 
+
 Texture* CreateTexture(unsigned int width, unsigned int height);

src/Renderer/Renderer.cpp

@@ -11,9 +11,11 @@
 #include <glm/gtc/type_ptr.hpp>
 #include "../Primitives/Scene.h"
 #include "../model.h"
+#include "../Utils.h"
 static enum class RenderPass {
     NONE = 0,
     SKYBOX,
+    HDR_SKYBOX,
     DEFAULT,
     PBR
 };
@@ -43,6 +45,84 @@ unsigned int normal;
 unsigned int metallic;
 unsigned int roughness;
 unsigned int ao;
+
+
+unsigned int cubeVAO = 0; 
+unsigned int cubeVBO = 0;
+void renderCube() {
+    if (cubeVAO == 0) {
+        float vertices[] = {
+            // back face
+            -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
+             1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
+             1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 0.0f, // bottom-right         
+             1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
+            -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
+            -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 1.0f, // top-left
+            // front face
+            -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
+             1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 0.0f, // bottom-right
+             1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
+             1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
+            -1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 1.0f, // top-left
+            -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
+            // left face
+            -1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
+            -1.0f,  1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-left
+            -1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
+            -1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
+            -1.0f, -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-right
+            -1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
+            // right face
+             1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
+             1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
+             1.0f,  1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-right         
+             1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
+             1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
+             1.0f, -1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-left     
+             // bottom face
+             -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
+              1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 1.0f, // top-left
+              1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
+              1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
+             -1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 0.0f, // bottom-right
+             -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
+             // top face
+             -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
+              1.0f,  1.0f , 1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
+              1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 1.0f, // top-right     
+              1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
+             -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
+             -1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 0.0f  // bottom-left        
+        };
+        glGenVertexArrays(1, &cubeVAO);
+        glGenBuffers(1, &cubeVBO);
+        // fill buffer
+        glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+        // link vertex attributes
+        glBindVertexArray(cubeVAO);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+        glEnableVertexAttribArray(1);
+        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+        glEnableVertexAttribArray(2);
+        glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        glBindVertexArray(0);
+
+    }
+
+    // render Cube
+    glBindVertexArray(cubeVAO);
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+    glBindVertexArray(0);
+}
+
+
+unsigned int irradianceMap;
+unsigned int envCubemap;
+unsigned int envMapVAO;
 void Renderer::Setup()
 {
     // Create ScreenVAO
@@ -70,6 +150,8 @@ void Renderer::Setup()
     // Load shaders 
     shaders[static_cast<int>(RenderPass::SKYBOX)] = Shader();
     shaders[static_cast<int>(RenderPass::SKYBOX)].Load("../Shaders/skybox.vs", "../Shaders/Cubemap.fs");
+    shaders[static_cast<int>(RenderPass::HDR_SKYBOX)] = Shader();
+    shaders[static_cast<int>(RenderPass::HDR_SKYBOX)].Load("../Shaders/HDRSkybox.vs", "../Shaders/HDRSkybox.fs");
     shaders[static_cast<int>(RenderPass::DEFAULT)] = Shader();
     shaders[static_cast<int>(RenderPass::DEFAULT)].Load("../Shaders/shader.vs", "../Shaders/shader.fs");
     shaders[static_cast<int>(RenderPass::PBR)] = Shader();
@@ -83,6 +165,161 @@ void Renderer::Setup()
     ao = TextureFromFile("../Textures/rusted_iron/ao.png",".");
 
 
+    // Create the skybox from an HDR equirectangular environment map 
+    unsigned int captureFBO, captureRBO;
+    glGenFramebuffers(1, &captureFBO);
+    glGenRenderbuffers(1, &captureRBO);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+    glBindRenderbuffer(GL_RENDERBUFFER, captureRBO);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 512, 512);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, captureRBO);
+
+    glGenTextures(1, &envCubemap);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, envCubemap);
+    for (unsigned int i = 0; i < 6; ++i) {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, 512, 512, 0, GL_RGB, GL_FLOAT, nullptr);
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    glm::mat4 captureProjection = glm::perspective(glm::radians(90.0f), 1.0f, 0.1f, 10.0f);
+    glm::mat4 captureViews[] = {
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(1.0f,  0.0f,  0.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f,  1.0f,  0.0f), glm::vec3(0.0f,  0.0f,  1.0f)),
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, -1.0f,  0.0f), glm::vec3(0.0f,  0.0f, -1.0f)),
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f,  0.0f,  1.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+        glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f,  0.0f, -1.0f), glm::vec3(0.0f, -1.0f,  0.0f))
+    };
+
+    auto eqShader = Shader();
+    eqShader.Load("../Shaders/HDRMap.vs", "../Shaders/HDRMap.fs");
+
+    auto hdrTexture = LoadIBL("../Textures/photostudio.hdr");
+
+    eqShader.use();
+    eqShader.setInt("equirectangularMap", 0);
+    eqShader.setMat4("projection", captureProjection);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, hdrTexture);
+    
+    glViewport(0, 0, 512, 512);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+
+    for (unsigned int i = 0; i < 6; ++i) {
+        eqShader.setMat4("view", captureViews[i]);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, envCubemap, 0);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        renderCube();
+    }
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    // Generate irradiancemap
+    glGenTextures(1, &irradianceMap);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, irradianceMap);
+    for (unsigned int i = 0; i < 6; ++i) {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, 32, 32, 0, GL_RGB, GL_FLOAT, nullptr);
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+    glBindRenderbuffer(GL_RENDERBUFFER, captureRBO);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 32, 32);
+
+
+    auto irradianceShader = Shader();
+    irradianceShader.Load("../Shaders/skybox2.vs", "../Shaders/irradienceconv.fs");
+    irradianceShader.use();
+    irradianceShader.setInt("environmentMap", 0);
+    irradianceShader.setMat4("projection", captureProjection);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, envCubemap);
+
+    glViewport(0, 0, 32, 32);
+    glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+    for (unsigned int i = 0; i < 6; ++i) {
+        irradianceShader.setMat4("view", captureViews[i]);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, irradianceMap, 0);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        renderCube();
+    }
+    glViewport(0, 0, 800, 600); // restore viewport;
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+
+
+
+    std::vector<float> m_skyboxVertices = {
+        // positions          
+        -1.0f,  1.0f, -1.0f,
+        -1.0f, -1.0f, -1.0f,
+        1.0f, -1.0f, -1.0f,
+        1.0f, -1.0f, -1.0f,
+        1.0f,  1.0f, -1.0f,
+        -1.0f,  1.0f, -1.0f,
+
+        -1.0f, -1.0f,  1.0f,
+        -1.0f, -1.0f, -1.0f,
+        -1.0f,  1.0f, -1.0f,
+        -1.0f,  1.0f, -1.0f,
+        -1.0f,  1.0f,  1.0f,
+        -1.0f, -1.0f,  1.0f,
+
+        1.0f, -1.0f, -1.0f,
+        1.0f, -1.0f,  1.0f,
+        1.0f,  1.0f,  1.0f,
+        1.0f,  1.0f,  1.0f,
+        1.0f,  1.0f, -1.0f,
+        1.0f, -1.0f, -1.0f,
+
+        -1.0f, -1.0f,  1.0f,
+        -1.0f,  1.0f,  1.0f,
+        1.0f,  1.0f,  1.0f,
+        1.0f,  1.0f,  1.0f,
+        1.0f, -1.0f,  1.0f,
+        -1.0f, -1.0f,  1.0f,
+
+        -1.0f,  1.0f, -1.0f,
+        1.0f,  1.0f, -1.0f,
+        1.0f,  1.0f,  1.0f,
+        1.0f,  1.0f,  1.0f,
+        -1.0f,  1.0f,  1.0f,
+        -1.0f,  1.0f, -1.0f,
+
+        -1.0f, -1.0f, -1.0f,
+        -1.0f, -1.0f,  1.0f,
+        1.0f, -1.0f, -1.0f,
+        1.0f, -1.0f, -1.0f,
+        -1.0f, -1.0f,  1.0f,
+        1.0f, -1.0f,  1.0f
+    };
+    unsigned int envMapVBO;
+
+    glGenVertexArrays(1, &envMapVAO);
+    glBindVertexArray(envMapVAO);
+
+    glGenBuffers(1, &envMapVBO);
+    glBindBuffer(GL_ARRAY_BUFFER, envMapVBO);
+
+    glBufferData(GL_ARRAY_BUFFER, m_skyboxVertices.size() * sizeof(float), &m_skyboxVertices[0], GL_STATIC_DRAW);
+
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+
+    glBindVertexArray(0);
+
+
 }
 
 void Renderer::resize(int width, int height ) {
@@ -127,8 +364,6 @@ void Renderer::resize(int width, int height ) {
 
 }
 
-
-
 unsigned int sphereVAO = 0;
 unsigned int indexCount;
 void renderSphere() {
@@ -221,9 +456,6 @@ void renderSphere() {
     glDrawElements(GL_TRIANGLE_STRIP, indexCount, GL_UNSIGNED_INT, 0);
 }
 
-
-
-
 void Renderer::Render(Scene& scene)
 {
    
@@ -235,6 +467,7 @@ void Renderer::Render(Scene& scene)
     auto model = glm::mat4(1.0f);   
 
     // Skybox 
+#if false
     glDepthMask(GL_FALSE);
     Shader shader = shaders.at(static_cast<int>(RenderPass::SKYBOX));
 
@@ -252,6 +485,28 @@ void Renderer::Render(Scene& scene)
     scene.skybox.Unbind();
 
     glDepthMask(GL_TRUE);
+#endif 
+
+    //HDR Environment Skybox 
+    Shader shader = shaders.at(static_cast<int>(RenderPass::HDR_SKYBOX));
+
+    glDepthFunc(GL_LEQUAL);
+
+    shader.use();
+
+    shader.setMat4("projection", projection);
+    shader.setMat4("view", scene.MainCamera.GetViewMatrix());
+
+    glBindVertexArray(envMapVAO);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, envCubemap);
+
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+
+    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+    glBindVertexArray(0);
+
+    glDepthFunc(GL_LESS);
 
 
     // Phong lighting
@@ -284,6 +539,7 @@ void Renderer::Render(Scene& scene)
     shader.setInt("metallicMap", 2);
     shader.setInt("roughnessMap", 3);
     shader.setInt("aoMap", 4);
+    shader.setInt("irradianceMap", 5);
 
     shader.setMat4("projection", projection);
     view = scene.MainCamera.GetViewMatrix();
@@ -302,11 +558,14 @@ void Renderer::Render(Scene& scene)
     glActiveTexture(GL_TEXTURE3);
     glBindTexture(GL_TEXTURE_2D, roughness);
 
-
     glActiveTexture(GL_TEXTURE4);
     glBindTexture(GL_TEXTURE_2D, ao);
 
+    glActiveTexture(GL_TEXTURE5);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, irradianceMap);
 
+
+    // Render Spheres
     model = glm::mat4(1.0f);
     for (int row = 0; row < nrRows; ++row) {
         for (int col = 0; col < nrColumns; ++col) {

src/Utils.h

@@ -0,0 +1,32 @@
+#pragma once
+#include <string>
+#include <iostream>
+#include <stb_image.h>
+#include <glad/glad.h>
+
+
+int LoadIBL(std::string file_path) {
+    stbi_set_flip_vertically_on_load(true);
+    int width, height, nrComponents;
+    float* data = stbi_loadf(file_path.c_str(), &width, &height, &nrComponents, 0);
+    unsigned int hdrTexture;
+
+    if (data) {
+        glGenTextures(1, &hdrTexture);
+        glBindTexture(GL_TEXTURE_2D, hdrTexture);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, data);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+
+    }
+    else {
+        std::cout << "Failed to load HDR image." << std::endl;
+    }
+
+    return hdrTexture;
+}

src/main.cpp

@@ -71,8 +71,6 @@ public:
       renderer.Setup();
 
 
-
-
       //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
       while(!window.shouldClose())
       {