OpenGL:太阳、地球、月球模型模拟动画

源代码：

#include<stdio.h>

#define GLUT_DISABLE_ATEXIT_HACK

#include<gl/GLUT.H>

static float year = 0, day = 0;

void init(void)

{

glClearColor(0.0,0.0,0.0,0.0);

glShadeModel(GL_FLAT);//设定着色模式，使用图元中某个顶点的颜色来渲染整个图元。

}

void display(void)

{

glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1.0,1.0,1.0);

glLoadIdentity();

glPushMatrix();

gluLookAt(0.0,0.0,5,0.0,0.0,0.0,0.0,1.0,0.0);

//绘制太阳

glRotatef((GLfloat)year,0.0,1.0,0.0);

glutWireSphere(0.8,20,20);

//绘制地球

glRotatef((GLfloat)year,0.0,1.0,0.0);

glTranslatef(2.0,0.0,0.0);

glRotatef((GLfloat)day,0.0,1.0,0.0);

glutWireSphere(0.2,20,20);

//绘制月球

glRotatef((GLfloat)year,0.0,1.0,0.0);

glTranslatef(0.4,0.0,0.0);

glRotatef((GLfloat)day,0.0,1.0,0.0);

glutWireSphere(0.1,15,15);

//glutWireCube(2.0);

glPopMatrix();

glutSwapBuffers();

}

void spinDisplay(void)

{

year = year + 0.03;

if ( year > 360.0)

{

year = year - 360.0;

}

day = day + 0.06;

if ( day > 360.0)

{

day = day - 360.0;

}

glutPostRedisplay();

}

void reshape(int w,int h)

{

glViewport(0,0,(GLsizei) w,(GLsizei) h);//函数作用：用一个视景体截取图像

//glFrustum(-1.0,1.0,-1.0,1.0,-1.0,1.0);

glMatrixMode(GL_PROJECTION);//mode 指定哪一个矩阵堆栈是下一个矩阵操作的目标,参数表示接下来要进行投影相关的操作

glLoadIdentity();//设置当前变化矩阵为单位矩阵；单位矩阵就是对角线上都是1，其余元素皆为0的矩阵。然后复位

//glOrtho(-3.0,3.0,-3.0,3.0,-3.0,3.0);

glFrustum(-1.0,1.0,-1.0,1.0,1.5,20);

glMatrixMode(GL_MODELVIEW);//进行视景相关的操作

//glLoadIdentity();

}

int main(int argc,char** argv)

{

glutInit(&argc,argv);

glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);

glutInitWindowSize(600,600);

glutInitWindowPosition(50,50);

glutCreateWindow(argv[0]);

init();

glutDisplayFunc(display);

glutReshapeFunc(reshape);

glutIdleFunc(spinDisplay);

glutMainLoop();

return 0;

}

效果：



重要函数之：

gluLookAt(0.0,0.0,5,0.0,0.0,0.0,0.0,1.0,0.0);

作用：视点变换，初始化矩阵后，可使用此函数来制定视点变换，相当于设置相机的位置和方向。

参数理解：

第一组（三个数据为一组）：脑袋的位置

第二组：看得物体的位置

第三组：头顶朝向的方向