（Vries的原教程地址如下，https://learnopengl-cn.github.io/02 Lighting/06 Multiple lights/ 关于多光源的参数详情设置请看这个教程，本篇旨在对Vires基于visual studio的编程思想做Qt平台的移植，重在记录自身学习之用）
Qt开发平台：5.8.0
编译器：Desktop Qt 5.8.0 MSVC2015_64bit
本篇是对上篇三种投光物，平行光，点光源，手电筒的汇总，将三种类型的光源一同使用。
如下图所示：由一道平行光，四个点光源，一个手电筒光，叠加而成。
项目组织管理如下：
主要还是学习在shader中如何写函数，其实是与写c语言函数是一样的。
cube.vert
#version 330 core layout (location = 0) in vec3 aPos; layout (location = 1) in vec3 aNormal; layout (location = 2) in vec2 aTexCoords; uniform mat4 model; uniform mat4 view; uniform mat4 projection; out vec3 Normal; out vec3 FragPos; out vec2 TexCoords; void main(){ gl_Position = projection * view * model * vec4(aPos, 1.0f); Normal = mat3(transpose(inverse(model))) * aNormal;//预防scale对法线的干扰 FragPos = vec3(model * vec4(aPos, 1.0f)); TexCoords = aTexCoords; }
cube.frag
#version 330 core #define NR_POINT_LIGHTS 4 struct Material{ sampler2D diffuse; sampler2D specular; float shininess; }; struct DirLight{ vec3 direction; vec3 ambient; vec3 diffuse; vec3 specular; }; struct PointLight { vec3 position; float constant; float linear; float quadratic; vec3 ambient; vec3 diffuse; vec3 specular; }; struct SpotLight{ vec3 position; vec3 direction;//光源方向 vec3 ambient; vec3 diffuse; vec3 specular; float constant; float linear; float quadratic; float cutOff; float outerCutOff; }; vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir); vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir); vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir); uniform Material material; uniform DirLight dirLight; uniform PointLight pointLights[NR_POINT_LIGHTS]; uniform SpotLight spotLight; uniform vec3 viewPos; out vec4 FragColor; in vec2 TexCoords; in vec3 Normal; in vec3 FragPos; void main(){ // 属性 vec3 norm = normalize(Normal); vec3 viewDir = normalize(viewPos - FragPos); // 第一阶段：定向光照 vec3 result = CalcDirLight(dirLight, norm, viewDir); // 第二阶段：点光源 for(int i = 0; i < NR_POINT_LIGHTS; i++) result += CalcPointLight(pointLights[i], norm, FragPos, viewDir); //第三阶段：聚光 result += CalcSpotLight(spotLight, norm, FragPos, viewDir); FragColor = vec4(result, 1.0); } vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir){ vec3 lightDir = normalize(-light.direction); // 漫反射着色 float diff = max(dot(normal, lightDir), 0.0); // 镜面光着色 vec3 reflectDir = reflect(-lightDir, normal); float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess); // 合并结果 vec3 ambient = light.ambient * vec3(texture2D(material.diffuse, TexCoords)); vec3 diffuse = light.diffuse * diff * vec3(texture2D(material.diffuse, TexCoords)); vec3 specular = light.specular * spec * vec3(texture2D(material.specular, TexCoords)); return (ambient + diffuse + specular); } vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir){ vec3 lightDir = normalize(light.position - fragPos); // 漫反射着色 float diff = max(dot(normal, lightDir), 0.0); // 镜面光着色 vec3 reflectDir = reflect(-lightDir, normal); float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess); // 衰减 float distance = length(light.position - fragPos); float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance)); // 合并结果 vec3 ambient = light.ambient * vec3(texture2D(material.diffuse, TexCoords)); vec3 diffuse = light.diffuse * diff * vec3(texture2D(material.diffuse, TexCoords)); vec3 specular = light.specular * spec * vec3(texture2D(material.specular, TexCoords)); ambient *= attenuation; diffuse *= attenuation; specular *= attenuation; return (ambient + diffuse + specular); } vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir){ //ambient vec3 ambient = light.ambient * vec3(texture2D(material.diffuse, TexCoords)); //diffuse vec3 norm = normalize(Normal); vec3 lightDir = normalize(light.position - fragPos);//固定点光源 float diff = max(dot(norm, lightDir), 0.0f); vec3 diffuse = light.diffuse * (diff * vec3(texture2D(material.diffuse, TexCoords))); //specular vec3 reflectDir = reflect(-lightDir, norm); float spec = pow(max(dot(viewDir, reflectDir), 0.0f), material.shininess); vec3 specular = light.specular * (spec * vec3(texture2D(material.specular, TexCoords))); //all vec3 result = ambient + diffuse + specular; // 衰减 float distance = length(light.position - fragPos); float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance)); //手电筒 float theta = dot(lightDir, normalize(-light.direction)); float epsilon = light.cutOff - light.outerCutOff; float intensity = clamp((theta - light.outerCutOff)/epsilon, 0.0f, 1.0f); return result * intensity * attenuation; }
oglmanager.cpp
#include "oglmanager.h" #include <QKeyEvent> #include <QDebug> #include "resourcemanager.h" #include "cube.h" #include <QtMath> const QVector3D CAMERA_POSITION(0.0f, 0.0f, 3.0f); const QVector3D LIGHT_POSITION(0.0f, 2.0f, 0.0f); Cube *cube; OGLManager::OGLManager(GLuint w, GLuint h){ this->width = w; this->height = h; for(GLuint i = 0; i != 1024; ++i) keys[i] = GL_FALSE; } OGLManager::~OGLManager(){ delete this->camera; ResourceManager::clear(); } QVector3D pointLightPositions[] = { QVector3D( 0.7f, 0.2f, 2.0f), QVector3D( 2.3f, -3.3f, -4.0f), QVector3D(-4.0f, 2.0f, -12.0f), QVector3D( 0.0f, 0.0f, -3.0f) }; void OGLManager::init(){ cube = new Cube(); this->camera = new Camera(CAMERA_POSITION); cube->init(); core = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>(); ResourceManager::loadShader("cube", ":/shaders/res/shaders/cube.vert", ":/shaders/res/shaders/cube.frag"); ResourceManager::loadShader("light", ":/shaders/res/shaders/light.vert", ":/shaders/res/shaders/light.frag"); ResourceManager::getShader("cube").use().setInteger("material.diffuse", 0); ResourceManager::getShader("cube").use().setInteger("material.specular", 1); ResourceManager::getShader("cube").use().setFloat("material.shininess", 64.0f); //平行光 ResourceManager::getShader("cube").use().setVector3f("dirLight.direction", QVector3D(-0.2f, -1.0f, -0.3f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.ambient", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.diffuse", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.specular", QVector3D(0.5f, 0.5f, 0.5f)); //点光源 1 ResourceManager::getShader("cube").use().setVector3f("pointLights[0].position", pointLightPositions[0]); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].ambient", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].diffuse", QVector3D(0.8f, 0.8f, 0.8f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].specular", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setFloat("pointLights[0].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[0].linear", 0.09f); ResourceManager::getShader("cube").use().setFloat("pointLights[0].quadratic", 0.032f); //点光源 2 ResourceManager::getShader("cube").use().setVector3f("pointLights[1].position", pointLightPositions[1]); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].ambient", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].diffuse", QVector3D(0.8f, 0.8f, 0.8f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].specular", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setFloat("pointLights[1].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[1].linear", 0.09f); ResourceManager::getShader("cube").use().setFloat("pointLights[1].quadratic", 0.032f); //点光源 3 ResourceManager::getShader("cube").use().setVector3f("pointLights[2].position", pointLightPositions[2]); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].ambient", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].diffuse", QVector3D(0.8f, 0.8f, 0.8f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].specular", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setFloat("pointLights[2].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[2].linear", 0.09f); ResourceManager::getShader("cube").use().setFloat("pointLights[2].quadratic", 0.032f); //点光源 4 ResourceManager::getShader("cube").use().setVector3f("pointLights[3].position", pointLightPositions[3]); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].ambient", QVector3D(0.05f, 0.05f, 0.05f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].diffuse", QVector3D(0.8f, 0.8f, 0.8f)); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].specular", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setFloat("pointLights[3].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[3].linear", 0.09f); ResourceManager::getShader("cube").use().setFloat("pointLights[3].quadratic", 0.032f); //聚光灯 ResourceManager::getShader("cube").use().setVector3f("spotLight.position", camera->position); ResourceManager::getShader("cube").use().setVector3f("spotLight.direction", camera->front); ResourceManager::getShader("cube").use().setVector3f("spotLight.ambient", QVector3D(0.0f, 0.0f, 0.0f)); ResourceManager::getShader("cube").use().setVector3f("spotLight.diffuse", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setVector3f("spotLight.specular", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setFloat("spotLight.constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("spotLight.linear", 0.09f); ResourceManager::getShader("cube").use().setFloat("spotLight.quadratic", 0.032f); ResourceManager::getShader("cube").use().setFloat("spotLight.cutOff", cos(12.5f/180.0f*3.14)); ResourceManager::getShader("cube").use().setFloat("spotLight.outerCutOff", cos(15.5f/180.0f*3.14)); QMatrix4x4 model; ResourceManager::getShader("cube").use().setMatrix4f("model", model); //开启状态 core->glClearColor(0.1f, 0.1f, 0.1f, 1.0f); core->glEnable(GL_DEPTH_TEST); } void OGLManager::processInput(GLfloat dt){ if (keys[Qt::Key_W]) camera->processKeyboard(FORWARD, dt); if (keys[Qt::Key_S]) camera->processKeyboard(BACKWARD, dt); if (keys[Qt::Key_A]) camera->processKeyboard(LEFT, dt); if (keys[Qt::Key_D]) camera->processKeyboard(RIGHT, dt); if (keys[Qt::Key_E]) camera->processKeyboard(UP, dt); if (keys[Qt::Key_Q]) camera->processKeyboard(DOWN, dt); } void OGLManager::update(GLfloat dt){ QMatrix4x4 projection, model; projection.perspective(camera->zoom, (GLfloat)width/(GLfloat)height, 0.1f, 200.f); ResourceManager::getShader("cube").use().setMatrix4f("projection", projection); ResourceManager::getShader("cube").use().setMatrix4f("view", camera->getViewMatrix()); ResourceManager::getShader("cube").use().setVector3f("viewPos", camera->position); ResourceManager::getShader("light").use().setMatrix4f("projection", projection); ResourceManager::getShader("light").use().setMatrix4f("view", camera->getViewMatrix()); } void OGLManager::resize(GLuint w, GLuint h){ core->glViewport(0, 0, w, h); } QVector3D cubePositions[] = { QVector3D( 0.0f, 0.0f, 0.0f), QVector3D( 2.0f, 5.0f, -15.0f), QVector3D(-1.5f, -2.2f, -2.5f), QVector3D(-3.8f, -2.0f, -12.3f), QVector3D( 2.4f, -0.4f, -3.5f), QVector3D(-1.7f, 3.0f, -7.5f), QVector3D( 1.3f, -2.0f, -2.5f), QVector3D( 1.5f, 2.0f, -2.5f), QVector3D( 1.5f, 0.2f, -1.5f), QVector3D(-1.3f, 1.0f, -1.5f) }; void OGLManager::draw(GLfloat dt) { core->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); ResourceManager::getShader("light").use(); for (unsigned int i = 0; i < 4; i++){ QMatrix4x4 model; model.translate(pointLightPositions[i]); model.scale(0.2f); ResourceManager::getShader("light").use().setMatrix4f("model", model); cube->drawLight(); } for (unsigned int i = 0; i < 10; i++){ QMatrix4x4 model; model.translate(cubePositions[i]); GLfloat angle = 20.0f * i; model.rotate(angle, QVector3D(1.0f, 0.3f, 0.5f)); ResourceManager::getShader("cube").use().setMatrix4f("model", model); cube->drawCube(); } }
稍稍修改参数设置，就可以得到其他效果：
这里注意，对于点光源发绿光，只要很简单的修改
light.frag
#version 330 core out vec4 FragColor; void main() { FragColor = vec4(0.0f, 1.0f, 0.0f, 1.0f); }其余具体参数设置
oglmanager.cpp
.................... QVector3D pointLightColors[] = { QVector3D(0.4f, 0.7f, 0.1f), QVector3D(0.4f, 0.7f, 0.1f), QVector3D(0.4f, 0.7f, 0.1f), QVector3D(0.4f, 0.7f, 0.1f) }; void OGLManager::init(){ ................................. //平行光 ResourceManager::getShader("cube").use().setVector3f("dirLight.direction", QVector3D(-0.2f, -1.0f, -0.3f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.ambient", QVector3D(0.5f, 0.5f, 0.5f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.diffuse", QVector3D(1.0f, 1.0f, 1.0f)); ResourceManager::getShader("cube").use().setVector3f("dirLight.specular", QVector3D(1.0f, 1.0f, 1.0f)); //点光源 1 ResourceManager::getShader("cube").use().setVector3f("pointLights[0].position", pointLightPositions[0]); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].ambient", pointLightColors[0] * 0.1f); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].diffuse", pointLightColors[0]); ResourceManager::getShader("cube").use().setVector3f("pointLights[0].specular", pointLightColors[0]); ResourceManager::getShader("cube").use().setFloat("pointLights[0].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[0].linear", 0.07f); ResourceManager::getShader("cube").use().setFloat("pointLights[0].quadratic", 0.017f); //点光源 2 ResourceManager::getShader("cube").use().setVector3f("pointLights[1].position", pointLightPositions[1]); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].ambient", pointLightColors[1] * 0.1f); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].diffuse", pointLightColors[1]); ResourceManager::getShader("cube").use().setVector3f("pointLights[1].specular", pointLightColors[1]); ResourceManager::getShader("cube").use().setFloat("pointLights[1].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[1].linear", 0.07f); ResourceManager::getShader("cube").use().setFloat("pointLights[1].quadratic", 0.017f); //点光源 3 ResourceManager::getShader("cube").use().setVector3f("pointLights[2].position", pointLightPositions[2]); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].ambient", pointLightColors[2] * 0.1f); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].diffuse", pointLightColors[2]); ResourceManager::getShader("cube").use().setVector3f("pointLights[2].specular", pointLightColors[2]); ResourceManager::getShader("cube").use().setFloat("pointLights[2].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[2].linear", 0.07f); ResourceManager::getShader("cube").use().setFloat("pointLights[2].quadratic", 0.017f); //点光源 4 ResourceManager::getShader("cube").use().setVector3f("pointLights[3].position", pointLightPositions[3]); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].ambient", pointLightColors[3] * 0.1f); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].diffuse", pointLightColors[3]); ResourceManager::getShader("cube").use().setVector3f("pointLights[3].specular", pointLightColors[3]); ResourceManager::getShader("cube").use().setFloat("pointLights[3].constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("pointLights[3].linear", 0.07f); ResourceManager::getShader("cube").use().setFloat("pointLights[3].quadratic", 0.017f); //聚光灯 ResourceManager::getShader("cube").use().setVector3f("spotLight.position", camera->position); ResourceManager::getShader("cube").use().setVector3f("spotLight.direction", camera->front); ResourceManager::getShader("cube").use().setVector3f("spotLight.ambient", QVector3D(0.0f, 0.0f, 0.0f)); ResourceManager::getShader("cube").use().setVector3f("spotLight.diffuse", QVector3D(0.0f, 1.0f, 0.0f)); ResourceManager::getShader("cube").use().setVector3f("spotLight.specular", QVector3D(0.0f, 1.0f, 0.0f)); ResourceManager::getShader("cube").use().setFloat("spotLight.constant", 1.0f); ResourceManager::getShader("cube").use().setFloat("spotLight.linear", 0.07f); ResourceManager::getShader("cube").use().setFloat("spotLight.quadratic", 0.017f); ResourceManager::getShader("cube").use().setFloat("spotLight.cutOff", cos(7.0f/180.0f*3.14)); ResourceManager::getShader("cube").use().setFloat("spotLight.outerCutOff", cos(10.0f/180.0f*3.14)); core->glClearColor(0.9f, 0.9f, 0.9f, 1.0f); .............. }
