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LearnOpenGL09——材质

2021-02-16 21:30:33  阅读：139  来源： 互联网

标签：1.0 glm 0.0 float 0.5 LearnOpenGL09 vec3 材质


转自
https://blog.csdn.net/qq_36696486/article/details/104329131
https://learnopengl-cn.github.io/02%20Lighting/03%20Materials/
在现实世界里，每个物体会对光产生不同的反应。比如说，钢看起来通常会比陶瓷花瓶更闪闪发光，木头箱子也不会像钢制箱子那样对光产生很强的反射。每个物体对镜面高光也有不同的反应。有些物体反射光的时候不会有太多的散射(Scatter)，因而产生一个较小的高光点，而有些物体则会散射很多，产生一个有着更大半径的高光点。如果我们想要在OpenGL中模拟多种类型的物体，我们必须为每个物体分别定义一个材质(Material)属性。
在冯氏光照模型的基础上，我们将冯氏光照模型的三个组成成分再加上反光度封装成为一个结构体，便于对光照参数进行统一管理，这个结构体便是所谓的材质
材质可以简单理解为一个参数集合体，来控制物体的基本属性。在片段着色器中，我们创建一个结构体(Struct)来储存物体的材质属性。我们也可以把它们储存为独立的uniform值，但是作为一个结构体来储存会更有条理一些。

#version 330 core
struct Material {
    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
    float shininess;
}; 

uniform Material material;

示例程序：

示例程序在冯氏光照模型的基础上进行改动：
顶点着色器

#version 330 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec3 aNormal;

out vec3 FragPos;
//光照法向量
out vec3 Normal;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main(){
	FragPos = vec3(model * vec4(aPos,1.0));
	Normal = mat3(transpose(inverse(model)))*aNormal;
	
	gl_Position = projection * view * vec4(FragPos,1.0);

片元着色器

#version 330 core
out vec4 FragColor;

in vec3 Normal;
in vec3 FragPos;

uniform vec3 viewPos;
//物体颜色，对物体的pong着色操作在片元着色器中实现
uniform vec3 objectColor;

struct Light{
	vec3 lightPos;
	vec3 lightColor;
	float shininess;
};

//材质
uniform Light material;

void main(){
	// ambient
    float ambientStrength = 0.1;
    vec3 ambient = ambientStrength * material.lightColor;

	 // diffuse 
    vec3 norm = normalize(Normal);
    vec3 lightDir = normalize(material.lightPos - FragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = diff * material.lightColor;

	// specular
    float specularStrength = 0.5;
    vec3 viewDir = normalize(viewPos - FragPos);
    vec3 reflectDir = reflect(-lightDir, norm);  
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
    vec3 specular = specularStrength * spec * material.lightColor;  

	vec3 result = (ambient + diffuse + specular) * objectColor;
    FragColor = vec4(result, 1.0);

程序

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

//#include"camera.h"
#include <iostream>

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
// void mouse_callback(GLFWwindow* window, double xpos, double ypos);
// void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void processInput(GLFWwindow* window);

// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;

// camera
//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;

// timing
float deltaTime = 0.0f;
float lastFrame = 0.0f;

// lighting
glm::vec3 lightPos(1.2f, 1.0f, 2.0f);


const char* vertexShaderSource =
"#version 330 core\n"
"layout(location = 0) in vec3 aPos;\n"
"layout(location = 1) in vec3 aNormal;\n"

"out vec3 FragPos;\n"
"out vec3 Normal;\n"

"uniform mat4 model;\n"
"uniform mat4 view;\n"
"uniform mat4 projection;\n"

"void main()\n"
"{\n"
"FragPos = vec3(model * vec4(aPos, 1.0));\n"
"Normal = aNormal;\n"

"gl_Position = projection * view * vec4(FragPos, 1.0);\n"
"}\n";

const char* fragmentShaderSource =
"#version 330 core\n"
"out vec4 FragColor;\n"

"in vec3 Normal;\n"
"in vec3 FragPos;\n"

"uniform vec3 viewPos;\n"
"uniform vec3 objectColor;\n"
"struct Light {\n"
"float shininess;\n"
"vec3 lightPos;\n"
"vec3 lightColor;\n"
"};\n"

"uniform Light material;\n"

"void main()\n"
"{\n"
// ambient
"float ambientStrength = 0.1;\n"
"vec3 ambient = ambientStrength * material.lightColor;\n"

// diffuse 
"vec3 norm = normalize(Normal);\n"
"vec3 lightDir = normalize(material.lightPos - FragPos);\n"
"float diff = max(dot(norm, lightDir), 0.0);\n"
"vec3 diffuse = diff * material.lightColor;\n"

// specular
"float specularStrength = 0.5;\n"
"vec3 viewDir = normalize(viewPos - FragPos);\n"
"vec3 reflectDir = reflect(-lightDir, norm);\n"
"float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);\n"
"vec3 specular = specularStrength * spec * material.lightColor;\n"

"vec3 result = (ambient + diffuse + specular) * objectColor;\n"
"FragColor = vec4(result, 1.0);\n"
"}";


int main()
{
	//初始化
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);



	// 创建窗口
	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	if (window == NULL)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

	// 错误提示信息
	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}

	// 开启深度测试（深度值粗略可视为与相机近平面的距离）
	glEnable(GL_DEPTH_TEST);

	//VertexShader创建顶点着色器
	int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
	glCompileShader(vertexShader);

	//Info获取编译出错信息
	int success;
	char info[512];
	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(vertexShader, 512, NULL, info);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << info << std::endl;
	}



	//片元着色器
	int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
	glCompileShader(fragmentShader);
	//编译信息
	glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(fragmentShader, 512, NULL, info);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << info << std::endl;
	}


	//shaderProgramshader程序
	int shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);
	glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
	if (!success)
	{
		glGetProgramInfoLog(shaderProgram, 512, NULL, info);
		std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << info << std::endl;
	}


	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);
	float vertices[] = {
	-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
	 0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
	 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
	 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
	-0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
	-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,

	-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,
	 0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,
	 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,
	 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,
	-0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,
	-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,

	-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,
	-0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
	-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
	-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
	-0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,
	-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,

	 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,
	 0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
	 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
	 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
	 0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,
	 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,

	-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,
	 0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,
	 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
	 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
	-0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
	-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,

	-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
	 0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
	 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
	 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
	-0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
	-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f
	};
	// first, configure the cube's VAO (and VBO)
	unsigned int VBO, cubeVAO;
	glGenVertexArrays(1, &cubeVAO);
	glGenBuffers(1, &VBO);

	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

	glBindVertexArray(cubeVAO);

	// position attribute
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	// normal attribute
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
	glEnableVertexAttribArray(1);

	glUseProgram(shaderProgram);


	// render loop
	// -----------
	while (!glfwWindowShouldClose(window))
	{
		// input
		// -----
		processInput(window);

		// render
		// ------
		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // also clear the depth buffer now!


		// activate shader
		glUseProgram(shaderProgram);

		glm::vec3 objectColor(1.0f, 1.0f, 0.0f);
		objectColor = glm::vec3(sin((float)glfwGetTime()), 1.0f, 1.0f);
		glUniform3fv(glGetUniformLocation(shaderProgram, "objectColor"), 1, &objectColor[0]);

		glm::vec3 viewPos(1.0f, 1.0f, 0.0f);
		glUniform3fv(glGetUniformLocation(shaderProgram, "viewPos"), 1, &viewPos[0]);

		const glm::vec3 lightColor(1.0f, 1.0f, 1.0f);
		glUniform3fv(glGetUniformLocation(shaderProgram, "material.lightColor"), 1, &lightColor[0]);
		int a = glGetUniformLocation(shaderProgram, "material.lightColor");

		const float shininess = 32.0f;
		glUniform1f(glGetUniformLocation(shaderProgram, "material.shininess"), 32.0f);

		const glm::vec3 lightPos(1.0f, 0.5f, 0.31f);
		glUniform3fv(glGetUniformLocation(shaderProgram, "material.lightPos"), 1, &lightPos[0]);


		// create transformations
		glm::mat4 model = glm::mat4(1.0f); // make sure to initialize matrix to identity matrix first
		glm::mat4 view = glm::mat4(1.0f);
		glm::mat4 projection = glm::mat4(1.0f);
		model = glm::rotate(model, (float)glfwGetTime() * 100, glm::vec3(1.0f, 1.0f, 0.0f));
		view = glm::translate(view, glm::vec3(0.0f, 0.0f, -200.0f));
		projection = glm::perspective(glm::radians(80.0f), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 300.0f);

		// retrieve the matrix uniform locations
		unsigned int modelLoc = glGetUniformLocation(shaderProgram, "model");
		unsigned int viewLoc = glGetUniformLocation(shaderProgram, "view");

		glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
		glUniformMatrix4fv(viewLoc, 1, GL_FALSE, &view[0][0]);

		glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "projection"), 1, GL_FALSE, &projection[0][0]);
		// render box
		glBindVertexArray(cubeVAO);
		glDrawArrays(GL_TRIANGLES, 0, 36);
		//glPolygonMode(GL_FRONT, GL_LINE);

		glfwSwapBuffers(window);
		glfwPollEvents();
	}


	glDeleteVertexArrays(1, &cubeVAO);
	glDeleteBuffers(1, &VBO);


	glfwTerminate();
	return 0;
}


void processInput(GLFWwindow* window)
{
	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
		glfwSetWindowShouldClose(window, true);
}


void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
	glViewport(0, 0, width, height);
}

在这里插入图片描述
在这里插入图片描述

标签：1.0,glm,0.0,float,0.5,LearnOpenGL09,vec3,材质
来源： https://blog.csdn.net/J_avaSmallWhite/article/details/113828301

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