[图形学]OpenGL实现斯坦福兔子(Stanford Bunny)实验代码
文章目录
-
- 项目整体文件结构
- 兔子数据(ply2文件)
- main.cpp
- bunny.fs 兔子面元着色器
- bunny.vs 兔子顶点着色器
- lamp.fs 灯光面元着色器
- lamp.vs 灯光顶点着色器
- camera.h 相机头文件
- parser.h 读取数据头文件
- parser.cpp 读取数据源文件
- select.fs 选取面元着色器
- select.vs 选取顶点着色器
- shader.h 着色器头文件
- 运行结果
- 参考
作者运行环境：XCode Version 12.3 (12C33)
需要先自行配置opengl,glfw,glad,glm的环境。（用homebrew命令行下载，并在项目里配置路径即可。
项目源代码：
链接: https://pan.baidu.com/s/1aMGJGCb8vUvaw3dCBbOkow 密码: go4e
项目整体文件结构
![[图形学]OpenGL实现斯坦福兔子(Stanford Bunny)实验代码_第1张图片](http://img.e-com-net.com/image/info8/5bb907bcdbe84014b7ddf8c4bda51cd5.jpg)
兔子数据(ply2文件)
链接: https://pan.baidu.com/s/1itfQ_GsuBPH0ehqCUzt_Ew 密码: c7r9
main.cpp
/// OpenGL Mathematics (GLM) is a header only C++ mathematics library for graphics software based on the OpenGL Shading Language (GLSL) specifications.
#include bunny.fs 兔子面元着色器
// Shader function executes once per fragment
// Outputs color of surface at the current fragment's screen sample position
#version 330 core // 版本号
out vec4 FragColor; // 输出变量
///兔子面元着色器
// 定义材质
struct Material {
vec3 ambient; // 环境光
vec3 diffuse; // 漫反射
vec3 specular; // 镜面反射
float shininess; // 反光度
};
// 定义点光源
struct PointLight {
vec3 position;
float constant;
float linear;
float quadratic;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
// 定义聚光灯光源
struct SpotLight {
vec3 position; // 光源顶点位置
vec3 direction; // 母线方向
float cutOff; // 切光角
float outerCutOff;
// 实现衰减的二次项的系数
float constant; // 常量
float linear; // 一次项系数
float quadratic; // 二次项系数
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
in vec3 FragPos;
in vec3 Normal; // 方向量
// 全局共享变量
uniform vec3 viewPos; // 摄像机位置(观察点)
uniform PointLight pointLights; // 点光源
uniform SpotLight spotLight; // 聚光灯光源
uniform Material material; // 材质
// function prototypes
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
vec3 CalcSpotLight(SpotLight light , vec3 normal , vec3 fragPos, vec3 viewDir);
void main(){
// 属性(需要标准化)
vec3 norm = normalize(Normal); // 法向
vec3 viewDir = normalize(viewPos - FragPos); // 最终方向向量
// == =====================================================
// Our lighting is set up in 2 phases: a point light and a flashlight
// For each phase, a calculate function is defined that calculates the corresponding color per lamp. In the main() function we take all the calculated colors and sum them up for this fragment's final color.
// == =====================================================
// phase 1: point lights
vec3 result = CalcPointLight(pointLights, norm, FragPos, viewDir);
// phase 2: spot light
result += CalcSpotLight(spotLight, norm, FragPos, viewDir);
// 设置片元颜色,采用RGBA
FragColor = vec4(result, 1.0);
}
// 计算使用点光源时的光照
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir){
vec3 lightDir = normalize(light.position - fragPos);
// 漫反射光照
// 计算光源对当前片段实际的漫发射影响(两个向量之间的角度大于90度，点乘的结果就会变成负数，为此，我们使用max函数返回两个参数之间较大的参数，从而保证漫反射分量不会变成负数)
float diff = max(dot(normal, lightDir), 0.0);
// 镜面反射光照
vec3 reflectDir = reflect(-lightDir, normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
// 光线衰减
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
// combine results
vec3 ambient = light.ambient * material.ambient;
vec3 diffuse = light.diffuse * diff * material.diffuse;
vec3 specular = light.specular * spec * material.specular;
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
return (ambient + diffuse + specular); //点光源颜色
}
// 计算使用聚光灯的颜色
vec3 CalcSpotLight(SpotLight 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);
// 光照衰减
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
// spotlight intensity
float theta = dot(lightDir, normalize(-light.direction));
float epsilon = light.cutOff - light.outerCutOff;
float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
// 综合光照
vec3 ambient = light.ambient * material.diffuse;
vec3 diffuse = light.diffuse * material.diffuse;
vec3 specular = light.specular * spec * material.specular;
ambient *= attenuation * intensity;
diffuse *= attenuation * intensity;
specular *= attenuation * intensity;
return (ambient + diffuse + specular); //聚光灯颜色
}
bunny.vs 兔子顶点着色器
#version 330 core
// 输入变量也叫顶点属性(Vertex Attribute),能声明的顶点属性是有上限的
// 为了定义顶点数据该如何管理，使用location这一个元数据指定输入变量，这样才可以在CPU上配置顶点属性。
layout (location = 0) in vec3 aPos; // 位置变量属性 = 0
layout (location = 1) in vec3 aNormal;
out vec3 FragPos; // 片元的位置
out vec3 Normal; // 添加法向量
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);
}
lamp.fs 灯光面元着色器
#version 330 core
out vec4 FragColor;
void main(){
FragColor = vec4(1.0); // set alle 4 vector values to 1.0
}
lamp.vs 灯光顶点着色器
#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);
}
camera.h 相机头文件
#ifndef CAMERA_H
#define CAMERA_H
#include parser.h 读取数据头文件
#ifndef PARSER_H
#define PARSER_H
#include parser.cpp 读取数据源文件
#include "parser.h"
// 读取原始的ply2文件,顶点为三个元素
void parseIndex(const char* fileName, GLfloat* vertices, GLuint* indices, GLuint& vertices_size, GLuint& indices_size){
std::FILE* f = std::fopen(fileName, "r");
// 先读取前两行,分别是顶点数和面元个数
std::fscanf(f, "%d%d", &vertices_size, &indices_size);
// cout << vertices_size << endl << indices_size << endl;
for(int i = 0; i < vertices_size; i++){
std::fscanf(f, "%f%f%f", &vertices[3*i], &vertices[3*i+1], &vertices[3*i+2]);
}
for(int i = 0; i < indices_size; i++){
int _;
std::fscanf(f, "%d%d%d%d", &_, &indices[3*i], &indices[3*i+1], &indices[3*i+2]);
}
std::fclose(f);
}
// 读取更新后的ply2_normal文件,顶点为六个元素,后面三个是法向量(?)
void parseNormal(const char* fileName, GLfloat* vertices, GLuint* indices, GLuint& vertices_size, GLuint& indices_size){
std::FILE* f = std::fopen(fileName, "r");
std::fscanf(f, "%d%d", &vertices_size, &indices_size);
// cout << vertices_size << endl << indices_size << endl;
for(int i = 0; i < vertices_size; i++){
std::fscanf(f, "%f%f%f%f%f%f", &vertices[6*i], &vertices[6*i+1], &vertices[6*i+2], \
&vertices[6*i+3], &vertices[6*i+4], &vertices[6*i+5]);
}
for(int i = 0; i < indices_size; i++){
std::fscanf(f, "%d%d%d", &indices[3*i], &indices[3*i+1], &indices[3*i+2]);
}
std::fclose(f);
}
select.fs 选取面元着色器
#version 330 core
out vec4 FragColor;
void main(){
FragColor = vec4(1.0); // set alle 4 vector values to 1.0
}
select.vs 选取顶点着色器
#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);
}
shader.h 着色器头文件
#ifndef SHADER_H
#define SHADER_H
#include 运行结果
链接: https://pan.baidu.com/s/1HiOmeDFZx9G7Nskw08BW5Q 密码: a1i9
参考
https://learnopengl-cn.github.io/
非原创，侵删([email protected]）