C++ 为3D杯子创建圆柱体底座(现代OpenGL、GLM)
嘿,我很难弄清楚如何为我需要绘制的3D杯子创建360底座。 我正在使用GLEW、GLFW和GLM数学 到目前为止,我已经到了可以创建三维立方体和三维金字塔的地步。到目前为止,我的想法是,我需要以360度的方式创建6个或更多的三角形副本。我该怎么做?除了创建三角形、立方体和金字塔,现代OpenGL的资源并不多 守则:C++ 为3D杯子创建圆柱体底座(现代OpenGL、GLM),c++,opengl,3d,glm-math,C++,Opengl,3d,Glm Math,嘿,我很难弄清楚如何为我需要绘制的3D杯子创建360底座。 我正在使用GLEW、GLFW和GLM数学 到目前为止,我已经到了可以创建三维立方体和三维金字塔的地步。到目前为止,我的想法是,我需要以360度的方式创建6个或更多的三角形副本。我该怎么做?除了创建三角形、立方体和金字塔,现代OpenGL的资源并不多 守则: #include <GLEW/glew.h> #include <GLFW/glfw3.h> #include <iostream> // GL
#include <GLEW/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
// GLM Mathematics
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
using namespace std;
int width, height;
const double PI = 3.14159;
const float toRadians = PI / 180.0f;
// Draw Primitive(s)
void draw()
{
GLenum mode = GL_TRIANGLES;
GLsizei indices = 6;
glDrawElements(mode, indices, GL_UNSIGNED_BYTE, nullptr);
}
// Input Function Prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
static void cursor_position_callback(GLFWwindow* window, double xpos, double ypos);
void mouse_button_callback(GLFWwindow* window, int button, int action, int mods);
// Declare View Matrix
glm::mat4 viewMatrix;
// Initialize FOV
GLfloat fov = 45.0f;
// Define Camera Attributes
glm::vec3 cameraPosition = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 target = glm::vec3(0.0f, 0.0f, 0.0f);
glm::vec3 cameraDirection = glm::normalize(cameraPosition - target);
glm::vec3 worldUp = glm::vec3(0.0f, 1.0f, 0.0f);
glm::vec3 cameraRight = glm::normalize(glm::cross(worldUp, cameraDirection));
glm::vec3 cameraUp = glm::normalize(glm::cross(cameraDirection, cameraRight));
glm::vec3 cameraFront = glm::normalize(glm::vec3(0.0f, 0.0f, -1.0f));
// Declare target prototype
glm::vec3 getTarget();
// Camera transformation prototype
void TransformCamera();
// Boolean array for keys and mouse buttons
bool keys[1024], mouseButtons[3];
// Boolean to check camera transformation
bool isPanning = false, isOrbiting = false, isZooming = false;
// Radius, Pitch, and Yaw
GLfloat radius = 3.0f, rawYaw = 0.0f, rawPitch = 0.0f, degYaw, degPitch;
GLfloat deltaTime = 0.0f, lastFrame = 0.0f;
GLfloat lastX = 320, lastY = 240, xChange, yChange;
// Check for any initial mouse movement
bool firstMouseMove = true;
void initCamera();
// Create and Compile Shaders
static GLuint CompileShader(const string& source, GLuint shaderType)
{
// Create Shader object
GLuint shaderID = glCreateShader(shaderType);
const char* src = source.c_str();
// Attach source code to Shader object
glShaderSource(shaderID, 1, &src, nullptr);
// Compile Shader
glCompileShader(shaderID);
// Return ID of Compiled shader
return shaderID;
}
// Create Program Object
static GLuint CreateShaderProgram(const string& vertexShader, const string& fragmentShader)
{
// Compile vertex shader
GLuint vertexShaderComp = CompileShader(vertexShader, GL_VERTEX_SHADER);
// Compile fragment shader
GLuint fragmentShaderComp = CompileShader(fragmentShader, GL_FRAGMENT_SHADER);
// Create program object
GLuint shaderProgram = glCreateProgram();
// Attach vertex and fragment shaders to program object
glAttachShader(shaderProgram, vertexShaderComp);
glAttachShader(shaderProgram, fragmentShaderComp);
// Link shaders to create executable
glLinkProgram(shaderProgram);
// Delete compiled vertex and fragment shaders
glDeleteShader(vertexShaderComp);
glDeleteShader(fragmentShaderComp);
// Return Shader Program
return shaderProgram;
}
int main(void)
{
width = 640; height = 480;
GLFWwindow* window;
/* Initialize the library */
if (!glfwInit())
return -1;
/* Create a windowed mode window and its OpenGL context */
window = glfwCreateWindow(width, height, "Main Window", NULL, NULL);
if (!window)
{
glfwTerminate();
return -1;
}
// Set input callback functions
glfwSetKeyCallback(window, key_callback);
glfwSetCursorPosCallback(window, cursor_position_callback);
glfwSetMouseButtonCallback(window, mouse_button_callback);
glfwSetScrollCallback(window, scroll_callback);
/* Make the window's context current */
glfwMakeContextCurrent(window);
// Initialize GLEW
if (glewInit() != GLEW_OK)
cout << "Error!" << endl;
GLfloat vertices[] = {
// Triangle 1
-0.5, -0.5, 0.0, // index 0
1.0, 0.0, 0.0, // red
-0.5, 0.5, 0.0, // index 1
0.0, 1.0, 0.0, // green
0.5, -0.5, 0.0, // index 2
0.0, 0.0, 1.0, // blue
// Triangle 2
0.5, 0.5, 0.0, // index 3
1.0, 0.0, 1.0 // purple
};
// Define element indices
GLubyte indices[] = {
0, 1, 2,
1, 2, 3
};
// Plane Transforms
glm::vec3 planePositions[] = {
glm::vec3(0.0f, 0.0f, 0.5f),
glm::vec3(0.5f, 0.0f, 0.0f),
glm::vec3(0.0f, 0.0f, -0.5f),
glm::vec3(-0.5f, 0.0f, 0.0f)
};
glm::float32 planeRotations[] = {
0.0f, 90.0f, 0.0f, 90.0f
};
// Setup some OpenGL options
glEnable(GL_DEPTH_TEST);
// Wireframe mode
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
GLuint VBO, EBO, VAO;
glGenBuffers(1, &VBO); // Create VBO
glGenBuffers(1, &EBO); // Create EBO
glGenVertexArrays(1, &VAO); // Create VOA
glBindVertexArray(VAO);
// VBO and EBO Placed in User-Defined VAO
glBindBuffer(GL_ARRAY_BUFFER, VBO); // Select VBO
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO); // Select EBO
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); // Load vertex attributes
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW); // Load indices
// Specify attribute location and layout to GPU
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
glEnableVertexAttribArray(1);
glBindVertexArray(0); // Unbind VOA or close off (Must call VOA explicitly in loop)
// Vertex shader source code
string vertexShaderSource =
"#version 330 core\n"
"layout(location = 0) in vec4 vPosition;"
"layout(location = 1) in vec4 aColor;"
"out vec4 oColor;"
"uniform mat4 model;"
"uniform mat4 view;"
"uniform mat4 projection;"
"void main()\n"
"{\n"
"gl_Position = projection * view * model * vPosition;"
"oColor = aColor;"
"}\n";
// Fragment shader source code
string fragmentShaderSource =
"#version 330 core\n"
"in vec4 oColor;"
"out vec4 fragColor;"
"void main()\n"
"{\n"
"fragColor = oColor;"
"}\n";
// Creating Shader Program
GLuint shaderProgram = CreateShaderProgram(vertexShaderSource, fragmentShaderSource);
/* Loop until the user closes the window */
while (!glfwWindowShouldClose(window))
{
// Set Delta time
GLfloat currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// Resize window and graphics simultaneously
glfwGetFramebufferSize(window, &width, &height);
glViewport(0, 0, width, height);
/* Render here */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Use Shader Program exe and select VAO before drawing
glUseProgram(shaderProgram); // Call Shader per-frame when updating attributes
// Declare transformations (can be initialized outside loop)
glm::mat4 projectionMatrix;
viewMatrix = glm::lookAt(cameraPosition, getTarget(), worldUp);
projectionMatrix = glm::perspective(fov, (GLfloat)width / (GLfloat)height, 0.1f, 100.0f);
// Get matrix's uniform location and set matrix
GLint modelLoc = glGetUniformLocation(shaderProgram, "model");
GLint viewLoc = glGetUniformLocation(shaderProgram, "view");
GLint projLoc = glGetUniformLocation(shaderProgram, "projection");
//glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(modelMatrix));
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(viewMatrix));
glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(projectionMatrix));
glBindVertexArray(VAO); // User-defined VAO must be called before draw.
for (GLuint i = 0; i < 4; i++)
{
glm::mat4 modelMatrix;
modelMatrix = glm::translate(modelMatrix, planePositions[i]);
modelMatrix = glm::rotate(modelMatrix, planeRotations[i] * toRadians, glm::vec3(0.0f, 1.0f, 0.0f));
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(modelMatrix));
// Draw primitive(s)
draw();
}
// Unbind Shader exe and VOA after drawing per frame
glBindVertexArray(0); //Incase different VAO wii be used after
glUseProgram(0); // Incase different shader will be used after
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
// Poll camera transformations
TransformCamera();
}
//Clear GPU resources
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteBuffers(1, &EBO);
glfwTerminate();
return 0;
}
// Define Input Callback Functions
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
// Display ASCII Keycode
// ALT = ASCII 342
//cout << "ASCII: " << key << endl;
if (action == GLFW_PRESS)
keys[key] = true;
else if (action == GLFW_RELEASE)
keys[key] = false;
}
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
/*
// Display scroll offset
if (yoffset > 0)
cout << "Scroll Up: ";
if (yoffset < 0)
cout << "Scroll down: ";
cout << yoffset << endl;
*/
/*
if (isZooming)
{
// Clamp FOV
if (fov >= 1.0f && fov <= 55.0f)
fov -= yoffset * 0.01f;
// Default FOV
if (fov < 1.0f)
fov = 1.0f;
if (fov > 45.0f)
fov = 45.0f;
}
*/
}
static void cursor_position_callback(GLFWwindow* window, double xpos, double ypos)
{
// cout << "Mouse X: " << xpos << endl;
// cout << "Mouse Y: " << ypos << endl;
if (firstMouseMove)
{
lastX = xpos;
lastY = ypos;
firstMouseMove = false;
}
// Calculate cursor offset
xChange = xpos - lastX;
yChange = lastY - ypos;
lastX = xpos;
lastY = ypos;
// Zoom Camera
if (isZooming)
{
if (fov < 1.0f)
fov = 1.0f;
if (fov > 45.0f)
fov = 45.0f;
if (xpos > 0)
fov -= lastX * 0.01f;
if (ypos > 0)
fov -= lastY * 0.01f;
}
// Pan camera
if (isPanning)
{
if (cameraPosition.z > 0.f)
cameraFront.z = 1.0f;
else
cameraFront.z = -1.0f;
GLfloat cameraSpeed = xChange * deltaTime;
cameraPosition += cameraSpeed * cameraRight;
cameraSpeed = yChange * deltaTime;
cameraPosition += cameraSpeed * cameraUp;
}
// Orbit camera
if (isOrbiting)
{
rawYaw += xChange;
rawPitch += yChange;
// Convert Yaw and Pitch to degrees
degYaw = glm::radians(rawYaw);
// degPitch = glm::radians(rawPitch);
degPitch = glm::clamp(glm::radians(rawPitch), -glm::pi<float>() / 2.0f + .1f, glm::pi<float>() / 2.0f - .1f);
// Azimuth Altitude Formula
cameraPosition.x = target.x + radius * cosf(degPitch) * sinf(degYaw);
cameraPosition.y = target.y + radius * sinf(degPitch);
cameraPosition.z = target.z + radius * cosf(degPitch) * cosf(degYaw);
}
}
void mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
{
/*
// Detect Mouse Button Clicks
if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS)
cout << "LMB Clicked" << endl;
if (button == GLFW_MOUSE_BUTTON_MIDDLE && action == GLFW_PRESS)
cout << "MMB Clicked" << endl;
if (button == GLFW_MOUSE_BUTTON_RIGHT && action == GLFW_PRESS)
cout << "RMB Clicked" << endl;
*/
if (action == GLFW_PRESS)
mouseButtons[button] = true;
else if (action == GLFW_RELEASE)
mouseButtons[button] = false;
}
// Define getTarget function
glm::vec3 getTarget()
{
if (isPanning)
target = cameraPosition + cameraFront;
return target;
}
// Define TransformCamera function
void TransformCamera()
{
// Pan camera if left alt key and middle mouse button pressed same time
if (keys[GLFW_KEY_LEFT_ALT] && mouseButtons[GLFW_MOUSE_BUTTON_MIDDLE])
isPanning = true;
else
isPanning = false;
// Orbit camera if left alt key and left mouse button pressed same time
if (keys[GLFW_KEY_LEFT_ALT] && mouseButtons[GLFW_MOUSE_BUTTON_LEFT])
isOrbiting = true;
else
isOrbiting = false;
// Zoom camera if left alt key and right mouse button pressed same time
if (keys[GLFW_KEY_LEFT_ALT] && mouseButtons[GLFW_MOUSE_BUTTON_RIGHT])
isZooming = true;
else
isZooming = false;
// Reset Camera
if (keys[GLFW_KEY_F])
initCamera();
}
void initCamera()
{
cameraPosition = glm::vec3(0.0f, 0.0f, 3.0f);
target = glm::vec3(0.0f, 0.0f, 0.0f);
cameraDirection = glm::normalize(cameraPosition - target);
worldUp = glm::vec3(0.0f, 1.0f, 0.0f);
cameraRight = glm::normalize(glm::cross(worldUp, cameraDirection));
cameraUp = glm::normalize(glm::cross(cameraDirection, cameraRight));
cameraFront = glm::normalize(glm::vec3(0.0f, 0.0f, -1.0f));
}
#包括
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//GLM数学
#包括
#包括
#包括
使用名称空间std;
int宽度、高度;
常数双PI=3.14159;
常数浮点环面=π/180.0f;
//绘制基本体
作废提款()
{
GLenum模式=GL_三角形;
GLsizei指数=6;
GLD元素(模式、索引、GLU无符号字节、空PTR);
}
//输入函数原型
void key_回调(GLFWwindow*窗口、int key、int scancode、int action、int mods);
void scroll_回调(GLFWwindow*窗口,双xoffset,双yoffset);
静态无效光标位置回调(GLFWwindow*窗口,双XPO,双YPO);
无效鼠标按钮回调(GLFWwindow*窗口、int按钮、int操作、int mods);
//声明视图矩阵
glm::mat4视图矩阵;
//初始化视场
GLFOV=45.0f;
//定义摄影机属性
glm::vec3 cameraPosition=glm::vec3(0.0f,0.0f,3.0f);
glm::vec3 target=glm::vec3(0.0f,0.0f,0.0f);
glm::vec3 cameraDirection=glm::normalize(cameraPosition-target);
glm::vec3 worldUp=glm::vec3(0.0f,1.0f,0.0f);
glm::vec3 cameraRight=glm::normalize(glm::cross(worldUp,CamerarDirection));
glm::vec3 cameraUp=glm::normalize(glm::cross(CamerarDirection,cameraRight));
glm::vec3 cameraFront=glm::normalize(glm::vec3(0.0f,0.0f,-1.0f));
//声明目标原型
glm::vec3 getTarget();
//摄像机变换原型
无效的照相机();
//键和鼠标按钮的布尔数组
布尔键[1024],鼠标按钮[3];
//用于检查摄影机变换的布尔值
bool isPanning=false,isOrbiting=false,isZooming=false;
//半径、俯仰和偏航
GLfloat半径=3.0f,横摆角=0.0f,横摆角=0.0f,反摆角,反摆角;
GLfloat deltaTime=0.0f,lastFrame=0.0f;
GLfloat lastX=320,lastY=240,xChange,yChange;
//检查是否有任何初始鼠标移动
bool firstMouseMove=true;
void initCamera();
//创建和编译着色器
静态GLuint编译器标头(常量字符串和源代码,GLuint着色器类型)
{
//创建着色器对象
GLuint shaderID=glCreateShader(shaderType);
const char*src=source.c_str();
//将源代码附加到着色器对象
glShaderSource(shaderID,1,&src,nullptr);
//编译着色器
glCompileShader(shaderID);
//已编译着色器的返回ID
返回shaderID;
}
//创建程序对象
静态GLuint CreateShaderProgram(常量字符串和顶点着色器、常量字符串和碎片着色器)
{
//编译顶点着色器
GLuint vertexShaderComp=编译器着色器(vertexShader,GL_VERTEX_着色器);
//编译片段着色器
GLuint fragmentShaderComp=编译器着色器(fragmentShader,GL\u FRAGMENT\u着色器);
//创建程序对象
GLuint shaderProgram=glCreateProgram();
//将顶点和片段着色器附着到程序对象
glAttachShader(着色器程序,vertexShaderComp);
glAttachShader(shaderProgram,fragmentShaderComp);
//链接着色器以创建可执行文件
GLLINK程序(着色器程序);
//删除已编译的顶点和片段着色器
glDeleteShader(vertexShaderComp);
glDeleteShader(fragmentShaderComp);
//返回着色器程序
返回着色器程序;
}
内部主(空)
{
宽度=640;高度=480;
GLFWwindow*窗口;
/*初始化库*/
如果(!glfwInit())
返回-1;
/*创建窗口模式窗口及其OpenGL上下文*/
window=glfwCreateWindow(宽度、高度、“主窗口”、NULL、NULL);
如果(!窗口)
{
glfwTerminate();
返回-1;
}
//设置输入回调函数
glfwSetKeyCallback(窗口、键回调);
glfwSetCursorPosCallback(窗口、光标位置回调);
glfwSetMouseButtonCallback(窗口、鼠标按钮回调);
glfwSetScrollCallback(窗口,滚动_回调);
/*将窗口的上下文设置为当前*/
glfwMakeContextCurrent(窗口);
//初始化GLEW
如果(glewInit()!=GLEW\u确定)
coutAFAIK,在OpenGL中绘制圆的最佳方法是使用如下三角形:
你基本上是在做比萨饼。切片越多,它看起来就越像一个圆。你可以使用GL_TRIANGLE_FAN来减少绘制圆所需的顶点数。我明白了。我开始手动绘制每个三角形。所以现在我有6个,但正如你所说,我想我需要更多才能使它更像一个圆。手动编码很烦人每一个并计算出6个以上三角形的顶点x、y更好的方法是:1.计算出圆周长上需要多少点2.将360除以点数-此值为“步长”量3.使用for循环,从角度0开始,并按步长量递增,直到达到360 4.在ea处对于for循环的ch迭代,计算当前角度的sin和cos;角度的cos乘以所需的圆半径即为X位置,与Y位置类似,但为sin。请参阅此海报代码: