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一、前言
二、简单光源
三、光照场景
3.1 创建光源
3.2 光源顶点着色器
3.3 光源片段着色器
3.4 物体片段着色器
3.5 光源位置 一、前言 我们看到的物体颜色是通过光照在物体#xff0c;然后反射到人眼成像#xff0c;具体而言是物体不能吸收的颜色。如白光照射…目录
一、前言
二、简单光源
三、光照场景
3.1 创建光源
3.2 光源顶点着色器
3.3 光源片段着色器
3.4 物体片段着色器
3.5 光源位置 一、前言 我们看到的物体颜色是通过光照在物体然后反射到人眼成像具体而言是物体不能吸收的颜色。如白光照射在蓝色物体上它吸收了除了蓝光之外所有颜色不吸收的蓝光反射到我们眼中。当物体颜色是多色光组合时珊瑚色该物体会反射不同强度的多个颜色最终形成珊瑚色。 二、简单光源
首先设置光源颜色和物体颜色如光源设置为白色物体设置为珊瑚色两种颜色相乘表示这个物体反射的颜色结果还是物体颜色。
glm::vec3 lightColor(1.0f, 1.0f, 1.0f);
glm::vec3 toyColor(1.0f, 0.5f, 0.31f);
glm::vec3 result lightColor * toyColor; // (1.0f, 0.5f, 0.31f);
三、光照场景
3.1 创建光源
使用立方体来表示光源创建光源的VAO
//创建光源VAO
unsigned int lightVAO;
glGenVertexArrays(1,lightVAO);
glBindVertexArray(lightVAO);
//绑定VBO由于箱子的VBO数据已经包含了立方体数据无需再次设置
glBindBuffer(GL_ARRAY_BUFFER,VBO);
//设置光源立方体顶点属性
glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,3*sizeof(float),(void*)0);
glEnableVertexAttribArray(0);
3.2 光源顶点着色器
容器的顶点位置不变仅需设置位置属性即可。
#version 330 core
layout (location 0) in vec3 aPos;uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;void main()
{gl_Position projection * view * model * vec4(aPos, 1.0);
}
3.3 光源片段着色器
设置光源时要创建另一套着色器保证其它光照着色器发生改变时不受影响。这里定义一个不变的常量白色保证灯的颜色一直是亮的
#version 330 coreout vec4 FragColor;void main()
{FragColor vec4(1.0);
}
3.4 物体片段着色器
这里直接定义物体颜色与光源颜色光照之后的结果即可
#version 330 core
out vec3 FragColor;uniform vec3 lightColor;
unifotm vec3 objectColor;void main()
{FragColor vec4(lightColor*objectColor,1.0);
}
3.5 光源位置
显示光源在3D场景中的具体位置可以给我们直观的光源感觉这里将光源一直设置为白色状态。
//设置灯源在世界坐标位置
glm::vec3 lightPos(1.2f, 1.0f, 2.0f);//把灯移动到这里并缩小
glm::mat4 model glm::mat4(1.0f);
model glm::translate(model, lightPos);
model glm::scale(model, glm::vec3(0.2f)); #include iostream
#include string#include glad.h
#include GL/glfw3.h
#define STB_IMAGE_IMPLEMENTATION
#include stb_image.h
#include glm/glm.hpp
#include glm/gtc/matrix_transform.hpp
#include glm/gtc/type_ptr.hpp
#include Shader.h
#include Camera.h//全局变量
const unsigned int SCR_WIDTH 800;
const unsigned int SCR_HEIGHT 600;Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
float lastX SCR_WIDTH / 2.0f;
float lastY SCR_HEIGHT / 2.0f;
bool firstMouse true;
float deltaTime 0.0f;
float lastFrame 0.0f;glm::vec3 lightPos(1.2f, 1.0f, 2.0f);float vertices[] {-0.5f, -0.5f, -0.5f,0.5f, -0.5f, -0.5f,0.5f, 0.5f, -0.5f,0.5f, 0.5f, -0.5f,-0.5f, 0.5f, -0.5f,-0.5f, -0.5f, -0.5f,-0.5f, -0.5f, 0.5f,0.5f, -0.5f, 0.5f,0.5f, 0.5f, 0.5f,0.5f, 0.5f, 0.5f,-0.5f, 0.5f, 0.5f,-0.5f, -0.5f, 0.5f,-0.5f, 0.5f, 0.5f,-0.5f, 0.5f, -0.5f,-0.5f, -0.5f, -0.5f,-0.5f, -0.5f, -0.5f,-0.5f, -0.5f, 0.5f,-0.5f, 0.5f, 0.5f,0.5f, 0.5f, 0.5f,0.5f, 0.5f, -0.5f,0.5f, -0.5f, -0.5f,0.5f, -0.5f, -0.5f,0.5f, -0.5f, 0.5f,0.5f, 0.5f, 0.5f,-0.5f, -0.5f, -0.5f,0.5f, -0.5f, -0.5f,0.5f, -0.5f, 0.5f,0.5f, -0.5f, 0.5f,-0.5f, -0.5f, 0.5f,-0.5f, -0.5f, -0.5f,-0.5f, 0.5f, -0.5f,0.5f, 0.5f, -0.5f,0.5f, 0.5f, 0.5f,0.5f, 0.5f, 0.5f,-0.5f, 0.5f, 0.5f,-0.5f, 0.5f, -0.5f,
};//回调函数
void processInput(GLFWwindow* window)
{if (glfwGetKey(window, GLFW_KEY_ESCAPE) GLFW_PRESS)glfwSetWindowShouldClose(window, true);//float cameraSpeed 0.05f; // adjust accordinglyfloat cameraSpeed 2.5f * deltaTime;if (glfwGetKey(window, GLFW_KEY_W) GLFW_PRESS)camera.ProcessKeyboard(FORWARD, deltaTime);//cameraPos cameraSpeed * cameraFront;if (glfwGetKey(window, GLFW_KEY_S) GLFW_PRESS)camera.ProcessKeyboard(BACKWARD, deltaTime);//cameraPos - cameraSpeed * cameraFront;if (glfwGetKey(window, GLFW_KEY_A) GLFW_PRESS)camera.ProcessKeyboard(LEFT, deltaTime);//cameraPos - glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;if (glfwGetKey(window, GLFW_KEY_D) GLFW_PRESS)camera.ProcessKeyboard(LEFT, RIGHT);//cameraPos glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;
}
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{// make sure the viewport matches the new window dimensions; note that width and // height will be significantly larger than specified on retina displays.glViewport(0, 0, width, height);
}
//3.0监听鼠标移动事件
void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{//仿止第一次进入窗口鼠标位置较远产生跳变if (firstMouse) // 这个bool变量初始时是设定为true的{lastX xpos;lastY ypos;firstMouse false;}float xoffset xpos - lastX;float yoffset lastY - ypos; // 注意这里是相反的因为y坐标是从底部往顶部依次增大的lastX xpos;lastY ypos;camera.ProcessMouseMovement(xoffset, yoffset);
}
//鼠标回调函数
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{camera.ProcessMouseScroll(static_castfloat(yoffset));
}int main()
{//glfw 初始化glfwInit();glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);//创建窗体GLFWwindow* pWD glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, Lighting, NULL, NULL);if (pWD NULL){std::cout Failed to create GLFW window std::endl;glfwTerminate();return -1;}//注册回调glfwMakeContextCurrent(pWD);glfwSetFramebufferSizeCallback(pWD, framebuffer_size_callback);glfwSetCursorPosCallback(pWD, mouse_callback);glfwSetScrollCallback(pWD, scroll_callback);//glfw捕捉鼠标glfwSetInputMode(pWD, GLFW_CURSOR, GLFW_CURSOR_DISABLED);//使用glad载入OpenGL函数地址int loadRet gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);if (!loadRet){std::cout Failed to initialize GLAD std::endl;return -1;}//使能深度测试glEnable(GL_DEPTH_TEST);//着色器Shader lightShader(light.vs, light.fms);Shader ObjShader(Obj.vs, Obj.fms);//导入物体顶点数据unsigned int VBO, ObjVAO;glGenVertexArrays(1, ObjVAO);glGenBuffers(1, VBO);glBindVertexArray(ObjVAO);glBindBuffer(GL_ARRAY_BUFFER,VBO);glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);/*index: 指定整体顶点属性索引 0 position;size指定每个顶点属性几个构成部分;type指定每个部分数据类型*//*normalized指定定点数据值是否需要被标准化true -11,访问时直接转化为定点值false*//*stride指定数据偏移步长设置为0让OpenGL去决定步长多少;*//*pointer表示位置数据在缓冲中起始位置的偏移量(Offset)*/glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);glEnableVertexAttribArray(0);//导入光源顶点数据unsigned int LightVAO;glGenVertexArrays(1, LightVAO);glBindVertexArray(LightVAO);glBindBuffer(GL_ARRAY_BUFFER,VBO);//前面数据已经传到内存了glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);glEnableVertexAttribArray(0);while (!glfwWindowShouldClose(pWD)){float currentFrame static_castfloat(glfwGetTime());deltaTime currentFrame - lastFrame;lastFrame currentFrame;processInput(pWD);glClearColor(0.1f, 0.1f, 0.1f, 1.0f);glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);//渲染物体ObjShader.use();ObjShader.setVec3(lightColor, 1.0f, 1.0f, 1.0f);ObjShader.setVec3(objColor, 1.0f, 0.5f, 0.31f);//model view projectionglm::mat4 model glm::mat4(1.0f);glm::mat4 view glm::mat4(1.0f);glm::mat4 projection glm::mat4(1.0f);view camera.GetViewMatrix();projection glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);ObjShader.setMat4(model, model);ObjShader.setMat4(view, view);ObjShader.setMat4(projection, projection);glBindVertexArray(ObjVAO);glDrawArrays(GL_TRIANGLES, 0, 36);//渲染 光源 画lightShader.use();model glm::mat4(1.0f);model glm::translate(model, lightPos);model glm::scale(model, glm::vec3(0.2f));lightShader.setMat4(model, model);lightShader.setMat4(view, view);lightShader.setMat4(projection, projection);glBindVertexArray(LightVAO);glDrawArrays(GL_TRIANGLES, 0, 36);//交换缓冲获取事件glfwSwapBuffers(pWD);glfwPollEvents();}glDeleteVertexArrays(1, LightVAO);glDeleteVertexArrays(1, ObjVAO);glDeleteBuffers(1, VBO);glfwTerminate();return 0;
}参考
颜色 - LearnOpenGL CN (learnopengl-cn.github.io)
