关于OpenGL的一个小问题(2)
本帖最后由 沉默的菜鸟 于 2019-9-7 21:46 编辑用OpenGL画了一个立方体，实现了鼠标手动旋转以及自动旋转等功能。
但碰到了一个棘手问题，就是当立方体自动旋转时，只有两面有颜色，另外的面为黑色，但我都设置了颜色的呀？？
求大神帮助。。。
代码：
ObjLoader.h
#pragma once
#include <GL/glut.h>
#include <vector>
#include <array>
#include <string>
using namespace std;
class ObjLoader
{
public:
ObjLoader() {};
ObjLoader( const string& filepath);
~ObjLoader();
void Paint();
private:
vector<array<GLfloat, 3>> vertexContainer;
vector<array<GLint, 3>> triangleContainer;
};
ObjLoader.cpp
#include "ObjLoader.h"
#include <fstream>
#include <iostream>
#include <sstream>
#include <direct.h>
ObjLoader::ObjLoader(const string& filepath)
{
string line;
ifstream f;
f.open(filepath, ios::in);
if (!f.is_open())
{
cout << "文件打开失败，请检查文件路径！" << endl;
return;
}
while (!f.eof())
{
getline(f, line);
cout << line << endl;
istringstream sin(line);
if (line=='v')
{
char flag;
float x, y, z;
sin >> flag >> x >> y >> z;
this->vertexContainer.push_back(array<GLfloat, 3>{x, y, z});
}
else if (line=='f')
{
char flag;
int p1, p2, p3;
sin >> flag >> p1 >> p2 >> p3;
this->triangleContainer.push_back(array<GLint, 3>{p1-1, p2-1, p3-1});
//因为顶点索引在obj文件中是从1开始的，而我们存放的顶点array是从0开始的，因此要减1
}
}
}
ObjLoader::~ObjLoader()
{
char buffer;
_getcwd(buffer,100);
string path = string(buffer);
string filename = "/data.obj";
ofstream out;
out.open(path+filename,ios::out);
if (!out.is_open())
{
cout << "写入路径错误！" << endl;
return;
}
for(auto vertex : this->vertexContainer)
{
out << "v " << vertex << " " << vertex << " " << vertex << endl;
}
for (auto triangle:this->triangleContainer)
{
out << "f " << triangle+1 << " " << triangle+1 << " " << triangle+1 << endl;
}
out.close();
cout << "写入文件成功！" << endl;
}
void ObjLoader::Paint()
{
glBegin(GL_TRIANGLES); //开始绘制
for (size_t i = 0; i < this->triangleContainer.size(); i++)
{
array<GLfloat, 3>VN;//三角形的单位法向量
//三个顶点
array<GLfloat, 3>Vertex1;
array<GLfloat, 3>Vertex2;
array<GLfloat, 3>Vertex3;
if (this->triangleContainer.size() != 3)
{
cout << "数据错误！" << endl;
}
else
{
GLint firstVertexIndex = (triangleContainer); //取出顶点索引
GLint secondVertexIndex = (triangleContainer);
GLint thirdVertexIndex = (triangleContainer);
for (size_t j = 0; j < 3; j++)
{
Vertex1 = vertexContainer; //顶点一
Vertex2 = vertexContainer; //顶点二
Vertex3 = vertexContainer; //顶点三
}
GLfloat vec1, vec2, vec3;//计算法向量
for (size_t z = 0; z < 3; z++)
{
vec1 = Vertex1 - Vertex2;//v1v2向量
vec2 = Vertex1 - Vertex3;//v1v3向量
}
//由v1v2向量与v1v3向量叉乘即可得平面的法向量
vec3 = vec1 * vec2 - vec1 * vec2;
vec3 = vec2 * vec1 - vec2 * vec1;
vec3 = vec2 * vec1 - vec2 * vec1;
//单位法向量
GLfloat D = sqrtf(pow(vec3, 2) + pow(vec3, 2) + pow(vec3, 2));
for (size_t n = 0; n < 3; n++)
{
VN = vec3 / D;
}
int p = 7;//扩大倍数
glColor3ub(163, 85, 104);
glNormal3f(VN, VN, VN);//绘制单位法向量
glColor3ub(163, 85, 104);
glVertex3f(Vertex1 *p, Vertex1 * p, Vertex1 * p);
glColor3ub(73,90,128);
glVertex3f(Vertex2 * p, Vertex2 * p, Vertex2 * p);
glColor3ub(221,240, 237);
glVertex3f(Vertex3 * p, Vertex3 * p, Vertex3 * p);
}
}
glEnd();
}
main.cpp
#include "ObjLoader.h"
#include <iostream>
using namespace std;
ObjLoader objModel;
int angles = 0; //转动角度
int xyz = { 0,1,0 };
//实现移动鼠标观察模型所需变量
static float c = 3.1415926f / 180.0f;
static float r = 1.0f;
static int degree = 90;
static int oldPosY = -1;
static int oldPosX = -1;
//安置光源
void setLightRes() {
GLfloat lightPosition[] = { 0.0f, 0.0f, 1.0f, 0.0f };
glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);
glEnable(GL_LIGHTING); //启用光源
glEnable(GL_LIGHT0); //使用指定灯光
}
//初始化
void init() {
cout << "please input the path of the obj file：";
string path;
cin >> path;
cout << endl;
objModel = ObjLoader(path);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutCreateWindow("ObjBuilder");
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_SMOOTH);
setLightRes();
glEnable(GL_DEPTH_TEST);
glColorMaterial(GL_FRONT, GL_DIFFUSE);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_AUTO_NORMAL);
glEnable(GL_NORMALIZE);
}
void timerPoc(int id)
{
angles += 20;
angles %= 360;
glutPostRedisplay();
glutTimerFunc(200, timerPoc, 1);
}
void display()
{
glColor3f(1.0, 1.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -20.0f);
glRotatef(angles, xyz, xyz, xyz);
setLightRes();
glPushMatrix();
gluLookAt(r * cos(c * degree), 0, r * sin(c * degree), 0.0f, 0.0f, 0.0f, 0.0f,1.0f, 0.0f);
objModel.Paint();//绘制obj模型
glPopMatrix();
glutSwapBuffers();
}
void keyboard(unsigned char key, int x, int y)
{
if (key == 114) {
glutTimerFunc(200, timerPoc, 1);
cout << "Unhandled key press r" << endl;
}
}
void reshape(int width, int height)
{
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0f, (GLdouble)width / (GLdouble)height, 1.0f, 200.0f);
glMatrixMode(GL_MODELVIEW);
}
//移动鼠标360观察模型
void moseMove(int button, int state, int x, int y)
{
if (state == GLUT_DOWN) {
oldPosX = x; oldPosY = y;
}
}
void changeViewPoint(int x, int y)
{
int temp = x - oldPosX;
degree += temp;
oldPosX = x;
oldPosY = y;
}
void myIdle()
{
glutPostRedisplay();
}
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
init();
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutReshapeFunc(reshape);
glutMouseFunc(moseMove);
glutMotionFunc(changeViewPoint);
glutIdleFunc(myIdle);
glutMainLoop();
return 0;
}
效果：
我觉得可能是光源的问题，但不知道怎么解决。。。
okxiaobo 发表于 2019-9-7 21:47
牛逼，高手啊
汗颜了，我才敢刚学{:1_924:}
okxiaobo 发表于 2019-9-7 21:48
这是光照问题
应该怎么改呢？？？
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