HDR skybox

.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;
+}

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 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 +165,122 @@ 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);
+    glViewport(0, 0, 800, 600); // restore viewport;
+
+    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 ) {
@@ -222,8 +420,6 @@ void renderSphere() {
 }
 
 
-
-
 void Renderer::Render(Scene& scene)
 {
    
@@ -235,6 +431,7 @@ 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 +449,28 @@ 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
@@ -306,7 +525,7 @@ void Renderer::Render(Scene& scene)
     glActiveTexture(GL_TEXTURE4);
     glBindTexture(GL_TEXTURE_2D, ao);
 
-
+    // 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())
       {