修复了计算BrdfLut的错误

ArchitectureColoredPainting/res/Shaders/brdf_lut.comp

@@ -110,7 +110,7 @@ vec2 IntegrateBRDF(float NdotV, float roughness)
 void main() 
 {
     uvec2 pixelLocation = gl_GlobalInvocationID.xy;
-    vec2 texCoords = vec2(pixelLocation)/vec2(imageSize(brdfLUT));
+    vec2 texCoords = (vec2(pixelLocation)+vec2(0.5))/vec2(imageSize(brdfLUT));
     vec2 integratedBRDF = IntegrateBRDF(texCoords.x, texCoords.y);
     imageStore(brdfLUT, ivec2(pixelLocation), vec4(integratedBRDF,0,0));
 }

ArchitectureColoredPainting/res/Shaders/model.frag

@@ -36,7 +36,6 @@ vec3 getNormalFromMap()
 
 void main()
 {      
-    //gBaseColor = vec4(1,0,0,1);
     gBaseColor = texture(texture_basecolor, TexCoords);
     if(gBaseColor.a<0.4)
         discard;

ArchitectureColoredPainting/res/Shaders/shader.frag

@@ -1,133 +1,25 @@
-#version 330 core
+#version 450 core
 
+layout (location = 0) out vec4 gBaseColor;
+layout (location = 1) out vec3 gNormal;
+layout (location = 2) out vec3 gPosition;
+layout (location = 3) out vec2 gMetallicRoughness;
+layout (location = 4) out uint gPaintingIndex;
 
-uniform sampler2D texture_basecolor;
-uniform sampler2D texture_metallic_roughness;
-uniform sampler2D texture_normal;
-
-out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
 
-// lights
+// material parameters
-uniform vec3 lightPositions[4];
+uniform vec3 albedo;
-uniform vec3 lightColors[4];
+uniform float metallic;
+uniform float roughness;
 
-uniform vec3 camPos;
-
-const float PI = 3.14159265359;
-
-vec3 getNormalFromMap()
-{
-    vec3 tangentNormal = texture(texture_normal, 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);
-}
-// ----------------------------------------------------------------------------
-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 nom   = a2;
-    float denom = (NdotH2 * (a2 - 1.0) + 1.0);
-    denom = PI * denom * denom;
-
-    return nom / denom;
-}
-// ----------------------------------------------------------------------------
-float GeometrySchlickGGX(float NdotV, float roughness)
-{
-    float r = (roughness + 1.0);
-    float k = (r*r) / 8.0;
-
-    float nom   = NdotV;
-    float denom = NdotV * (1.0 - k) + k;
-
-    return nom / 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 fresnelSchlick(float cosTheta, vec3 F0)
-{
-    return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
-}
 void main()
 {      
-    vec4 baseColor = texture(texture_basecolor, TexCoords);
+    gBaseColor = vec4(albedo, 1);
-    if(baseColor.a<0.4)
+    gPosition = WorldPos;
-        discard;
+    gNormal = normalize(Normal);
-
+    gMetallicRoughness = vec2(metallic,roughness);
-    vec3 albedo     = pow(baseColor.rgb, vec3(2.2));
+    gPaintingIndex = 0;
-    float metallic  = texture(texture_metallic_roughness, TexCoords).b;
-    float roughness = texture(texture_metallic_roughness, TexCoords).g;
-
-
-    vec3 N = getNormalFromMap();
-    vec3 V = normalize(camPos - WorldPos);
-
-    vec3 F0 = vec3(0.04); 
-    F0 = mix(F0, albedo, metallic);
-
-    // reflectance equation
-    vec3 Lo = vec3(0.0);
-    for(int i = 0; i < 1; ++i) 
-    {
-        // calculate per-light radiance
-        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;        
-
-        // cook-torrance brdf
-        float NDF = DistributionGGX(N, H, roughness);        
-        float G   = GeometrySmith(N, V, L, roughness);      
-        vec3  F   = fresnelSchlick(max(dot(H, V), 0.0), F0);
-        F = clamp(F,vec3(0),vec3(1));
-
-        vec3 kS = F;
-        vec3 kD = vec3(1.0) - kS;
-        kD *= 1.0 - metallic;     
-
-        vec3  nominator   = NDF * G * F;
-        float denominator = 4.0 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001; 
-        vec3  specular    = nominator / denominator;
-
-        // add to outgoing radiance Lo
-        float NdotL = max(dot(N, L), 0.0);                
-        Lo += (kD * albedo / PI + specular) * radiance * NdotL; 
-    
-    }   
-
-    vec3 ambient = vec3(0.03) * albedo;
-    vec3 color = ambient + Lo;
-
-    color = color / (color + vec3(1.0));
-    color = pow(color, vec3(1.0/2.2));  
-
-    FragColor = vec4(color, 1.0);
-
 }

ArchitectureColoredPainting/res/Shaders/shadow_mapping.comp

@@ -75,26 +75,26 @@ vec3 fresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness)
     return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(1.0 - cosTheta, 5.0);
 }   
 
-vec3 ambientLighting(vec3 N, vec3 V, vec3 F0, vec3 albedo,float metallic, float roughness, float ao)
+vec3 ambientLighting(vec3 N, vec3 V, vec3 F0, vec3 albedo, float metallic, float roughness, float ao)
 {
 	// ambient lighting (we now use IBL as the ambient term)
-    vec3 F = fresnelSchlickRoughness(max(dot(N, V), 0.0), F0, roughness);
+    vec3 F = fresnelSchlickRoughness(clamp(dot(N, V),0.,1.), F0, roughness);
     
     vec3 kS = F;
     vec3 kD = 1.0 - kS;
     kD *= 1.0 - metallic;	  
     
     vec3 irradiance = texture(irradianceMap, N).rgb;
-    vec3 diffuse      = irradiance * albedo;
+    vec3 diffuse    = irradiance * albedo;
     
     // sample both the pre-filter map and the BRDF lut and combine them together as per the Split-Sum approximation to get the IBL specular part.
     const float MAX_REFLECTION_LOD = 4.0;
 	vec3 R = reflect(-V, N); 
     vec3 prefilteredColor = textureLod(prefilterMap, R,  roughness * MAX_REFLECTION_LOD).rgb;    
-    vec2 brdf  = texture(brdfLUT, vec2(max(dot(N, V), 0.0), roughness)).rg;
+    vec2 brdf  = texture(brdfLUT, vec2(clamp(dot(N, V),0.,1.), roughness)).rg;
     vec3 specular = prefilteredColor * (F * brdf.x + brdf.y);
 
-    return (kD * diffuse + specular) * ao;
+	return (kD * diffuse + specular) * ao;
 }
 
 
@@ -200,7 +200,7 @@ void main()
 		imageStore(gBaseColor, pixelLocation, vec4(0));
 		return;
     }
-
+	normal = normalize(normal);
 
 	vec3 V = normalize(camPos - worldPos);
 

ArchitectureColoredPainting/src/Renderer/IblUtils.cpp

@@ -2,6 +2,7 @@
 #include <QOpenGLShaderProgram>
 #include <QDebug>
 #include <array>
+#include <glm/glm.hpp>
 #define STB_IMAGE_IMPLEMENTATION
 #include <stb_image.h>
 
@@ -77,6 +78,101 @@ void Renderer::IblUtils::renderCube(QOpenGLFunctions_4_5_Core* glFunc)
 	glFunc->glBindVertexArray(0);
 }
 
+void Renderer::IblUtils::renderSphere(QOpenGLFunctions_4_5_Core* glFunc)
+{
+	static unsigned int sphereVAO = 0;
+	static unsigned int indexCount;
+	if (sphereVAO == 0)
+	{
+		glFunc->glGenVertexArrays(1, &sphereVAO);
+
+		unsigned int vbo, ebo;
+		glFunc->glGenBuffers(1, &vbo);
+		glFunc->glGenBuffers(1, &ebo);
+
+		std::vector<glm::vec3> positions;
+		std::vector<glm::vec2> uv;
+		std::vector<glm::vec3> normals;
+		std::vector<unsigned int> indices;
+
+		const unsigned int X_SEGMENTS = 64;
+		const unsigned int Y_SEGMENTS = 64;
+		const float PI = 3.14159265359f;
+		for (unsigned int x = 0; x <= X_SEGMENTS; ++x)
+		{
+			for (unsigned int y = 0; y <= Y_SEGMENTS; ++y)
+			{
+				float xSegment = (float)x / (float)X_SEGMENTS;
+				float ySegment = (float)y / (float)Y_SEGMENTS;
+				float xPos = std::cos(xSegment * 2.0f * PI) * std::sin(ySegment * PI);
+				float yPos = std::cos(ySegment * PI);
+				float zPos = std::sin(xSegment * 2.0f * PI) * std::sin(ySegment * PI);
+
+				positions.push_back(glm::vec3(xPos, yPos, zPos));
+				uv.push_back(glm::vec2(xSegment, ySegment));
+				normals.push_back(glm::vec3(xPos, yPos, zPos));
+			}
+		}
+
+		bool oddRow = false;
+		for (unsigned int y = 0; y < Y_SEGMENTS; ++y)
+		{
+			if (!oddRow) // even rows: y == 0, y == 2; and so on
+			{
+				for (unsigned int x = 0; x <= X_SEGMENTS; ++x)
+				{
+					indices.push_back(y * (X_SEGMENTS + 1) + x);
+					indices.push_back((y + 1) * (X_SEGMENTS + 1) + x);
+				}
+			}
+			else
+			{
+				for (int x = X_SEGMENTS; x >= 0; --x)
+				{
+					indices.push_back((y + 1) * (X_SEGMENTS + 1) + x);
+					indices.push_back(y * (X_SEGMENTS + 1) + x);
+				}
+			}
+			oddRow = !oddRow;
+		}
+		indexCount = static_cast<unsigned int>(indices.size());
+
+		std::vector<float> data;
+		for (unsigned int i = 0; i < positions.size(); ++i)
+		{
+			data.push_back(positions[i].x);
+			data.push_back(positions[i].y);
+			data.push_back(positions[i].z);
+			if (normals.size() > 0)
+			{
+				data.push_back(normals[i].x);
+				data.push_back(normals[i].y);
+				data.push_back(normals[i].z);
+			}
+			if (uv.size() > 0)
+			{
+				data.push_back(uv[i].x);
+				data.push_back(uv[i].y);
+			}
+		}
+		glFunc->glBindVertexArray(sphereVAO);
+		glFunc->glBindBuffer(GL_ARRAY_BUFFER, vbo);
+		glFunc->glBufferData(GL_ARRAY_BUFFER, data.size() * sizeof(float), &data[0], GL_STATIC_DRAW);
+		glFunc->glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
+		glFunc->glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);
+		unsigned int stride = (3 + 2 + 3) * sizeof(float);
+		glFunc->glEnableVertexAttribArray(0);
+		glFunc->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, stride, (void*)0);
+		glFunc->glEnableVertexAttribArray(1);
+		glFunc->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, stride, (void*)(3 * sizeof(float)));
+		glFunc->glEnableVertexAttribArray(2);
+		glFunc->glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, stride, (void*)(6 * sizeof(float)));
+	}
+
+	glFunc->glBindVertexArray(sphereVAO);
+	glFunc->glDrawElements(GL_TRIANGLE_STRIP, indexCount, GL_UNSIGNED_INT, 0);
+}
+
 std::tuple<GLuint, GLuint, GLuint, GLuint> Renderer::IblUtils::precomputeCubemaps(QOpenGLFunctions_4_5_Core* glFunc)
 {
 	// pbr: setup framebuffer

ArchitectureColoredPainting/src/Renderer/IblUtils.h

@@ -8,10 +8,13 @@ namespace Renderer
 	public:
 		static constexpr int cubemapSize = 1024;
 		static void renderCube(QOpenGLFunctions_4_5_Core* glFunc);
+		static void renderSphere(QOpenGLFunctions_4_5_Core* glFunc);
 		/**
 		 * @brief 
 		 * @return GLuint envCubemap
 		 * @return GLuint irradianceMap
+		 * @return GLuint prefilterMap
+		 * @return GLuint brdfLut
 		 */
 		static std::tuple<GLuint, GLuint, GLuint, GLuint> precomputeCubemaps(QOpenGLFunctions_4_5_Core* glFunc);
 	private:

ArchitectureColoredPainting/src/Renderer/RendererGLWidget.cpp

@@ -121,6 +121,14 @@ void RendererGLWidget::initializeGL()
 	if (!shadowProgramPtr->link())
 		qDebug() << "ERROR:" << shadowProgramPtr->log();
 
+	plainProgramPtr = new QOpenGLShaderProgram;
+	if (!plainProgramPtr->addShaderFromSourceFile(QOpenGLShader::Vertex, ":/Shaders/shader.vert"))
+		qDebug() << "ERROR:" << plainProgramPtr->log();
+	if (!plainProgramPtr->addShaderFromSourceFile(QOpenGLShader::Fragment, ":/Shaders/shader.frag"))
+		qDebug() << "ERROR:" << plainProgramPtr->log();
+	if (!plainProgramPtr->link())
+		qDebug() << "ERROR:" << plainProgramPtr->log();
+
 	modelProgramPtr = new QOpenGLShaderProgram;
 	if (!modelProgramPtr->addShaderFromSourceFile(QOpenGLShader::Vertex, ":/Shaders/model.vert"))
 		qDebug() << "ERROR:" << modelProgramPtr->log();
@@ -303,6 +311,31 @@ void RendererGLWidget::paintGL()
 		if (model != nullptr)
 			model->draw();
 		
+		plainProgramPtr->bind();
+		plainProgramPtr->setUniformValue("projection", projection);
+		plainProgramPtr->setUniformValue("view", view);
+		plainProgramPtr->setUniformValue("albedo", 0.5f, 0.5f, 0.5f);
+		QMatrix4x4 model;
+		int nrRows = 7, nrColumns = 7;
+		float spacing = 2.5;
+		for (int row = 0; row < nrRows; ++row)
+		{
+			plainProgramPtr->setUniformValue("metallic", (float)row / (float)nrRows);
+			for (int col = 0; col < nrColumns; ++col)
+			{
+				plainProgramPtr->setUniformValue("roughness", glm::clamp((float)col / (float)nrColumns, 0.05f, 1.0f));
+				
+				model.setToIdentity();
+				model.scale(10);
+				model.translate(QVector3D((float)(col - (nrColumns / 2)) * spacing,
+					(float)(row - (nrRows / 2)) * spacing+20,
+					-2.0f));
+				plainProgramPtr->setUniformValue("model", model);
+				IblUtils::renderSphere(glFunc);
+			}
+		}
+		plainProgramPtr->release();
+
 		fboPtr->release();
 	}
 

ArchitectureColoredPainting/src/Renderer/RendererGLWidget.h

@@ -51,6 +51,7 @@ namespace Renderer
         float exposure = 0.8;
 
         QOpenGLShaderProgram* shadowProgramPtr = nullptr;
+        QOpenGLShaderProgram* plainProgramPtr = nullptr;
         QOpenGLShaderProgram* modelProgramPtr = nullptr;
         QOpenGLShaderProgram* paintingProgramPtr = nullptr;
         QOpenGLShaderProgram* paintingCompProgramPtr = nullptr;