计算机图形学与三维建模实验报告

1、计算机图形学实验报告openGL的基本使用1. 项目代码：/ 2321321.cpp : 定义控制台应用程序的入口点。#include "stdafx.h"#include<iostream>#include<stdio.h>#include<gl/glut.h>#include<gl/glu.h>#include<gl/gl.h>using namespace std;/#include"vgl.h" opengl4.3 编程宝典第8版库函数/#include"loadshaders

2、.h"GLfloat x=0.0,y=0.0,z=0.0;/用于平移的变量GLfloat i=1.0,j=1.0,k=1.0;/用于缩放的变量int d=1;/用于是否判断旋转的开关GLfloat angle=0.0f;/旋转角度的变量 void myDisplay(void)glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);/ 创建透视效果视图glMatrixMode(GL_PROJECTION);glLoadIdentity();gluPerspective(90.0f, 1.0f, 1.0f, 20.0f);glMatrixM

3、ode(GL_MODELVIEW);glLoadIdentity();gluLookAt(0.0, 0.0, 10.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);/ 定义4光源，从4个方向入射,第一个是白光，其他为红绿蓝GLfloat sun_light_position = -5.0f, 5.0f, 0.0f, 1.0f ;GLfloat sun_light_position1 = 5.0f, 5.0f, 0.0f, 1.0f ;GLfloat sun_light_pos

4、ition2 = -5.0f, -5.0f, 0.0f, 1.0f ;GLfloat sun_light_position3 = 5.0f, -5.0f, 0.0f, 1.0f ;GLfloat sun_light_ambient = 0.0f, 0.0f, 0.0f, 1.0f ;GLfloat sun_light_diffuse = 1.0f, 1.0f, 1.0f, 1.0f ;GLfloat sun_light_diffuse1 = 1.0f, 0.0f, 0.0f, 1.0f ;GLfloat sun_light_diffuse2 = 0.0f, 1.0f, 0.0f, 1.0f ;

5、GLfloat sun_light_diffuse3 = 0.0f, 0.0f, 1.0f, 1.0f ;GLfloat sun_light_specular = 1.0f, 1.0f, 1.0f, 1.0f ;glLightfv(GL_LIGHT0, GL_POSITION, sun_light_position);glLightfv(GL_LIGHT0, GL_AMBIENT, sun_light_ambient);glLightfv(GL_LIGHT0, GL_DIFFUSE, sun_light_diffuse);glLightfv(GL_LIGHT0, GL_SPECULAR, su

6、n_light_specular);glLightfv(GL_LIGHT1, GL_POSITION, sun_light_position1);glLightfv(GL_LIGHT1, GL_AMBIENT, sun_light_ambient);glLightfv(GL_LIGHT1, GL_DIFFUSE, sun_light_diffuse1);glLightfv(GL_LIGHT1, GL_SPECULAR, sun_light_specular);glLightfv(GL_LIGHT2, GL_POSITION, sun_light_position2);glLightfv(GL_

7、LIGHT2, GL_AMBIENT, sun_light_ambient);glLightfv(GL_LIGHT2, GL_DIFFUSE, sun_light_diffuse2);glLightfv(GL_LIGHT2, GL_SPECULAR, sun_light_specular);glLightfv(GL_LIGHT3, GL_POSITION, sun_light_position3);glLightfv(GL_LIGHT3, GL_AMBIENT, sun_light_ambient);glLightfv(GL_LIGHT3, GL_DIFFUSE, sun_light_diff

8、use3);glLightfv(GL_LIGHT3, GL_SPECULAR, sun_light_specular);glEnable(GL_LIGHT0); glEnable(GL_LIGHT1);glEnable(GL_LIGHT2);glEnable(GL_LIGHT3);glEnable(GL_LIGHTING);glEnable(GL_DEPTH_TEST);/绘制坐标轴glBegin(GL_LINE);/x轴 红色 glColor3f(1,0,0);glVertex3f(10,0,0);glVertex3f(-10,0,0);/y轴 绿色glColor3f(0,1,0);glVe

9、rtex3f(0,10,0);glVertex3f(0,-10,0);/z轴 蓝色glColor3f(0,0,1);glVertex3f(0,0,10);glVertex3f(0,0,-10);glEnd();/ 定义球体的材质并绘制GLfloat ambient = 0.2f, 0.2f, 0.2f, 1.0f ;/环境颜色GLfloat diffuse = 0.7f, 0.7f, 0.7f, 1.0f ;/散射颜色GLfloat specular = 1.0f, 1.0f, 1.0f, 1.0f ;/镜面反射GLfloat emission = 0.0f, 0.0f, 0.0f, 0.5f

10、 ;/发射光颜色GLfloat hininess = 50.0f; /反射指数glMaterialfv(GL_FRONT, GL_AMBIENT, ambient);glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuse);glMaterialfv(GL_FRONT, GL_SPECULAR, specular);glMaterialfv(GL_FRONT, GL_EMISSION, emission);glMaterialf(GL_FRONT, GL_SHININESS, shininess); glTranslatef(x,y,z);glScalef(i,j,

11、k);if(d=1) glRotatef(angle,0.0f,0.0f,4.0f);glTranslatef(2.5f,2.5f,0.0f);glutSolidSphere(2.0, 60.0, 60.0);glutSwapBuffers();void ChangeSize(GLsizei W,GLsizei H)/当视口改变时改变裁剪部分保证图形观察时不形变GLfloat aspectRatio;if(H=0)H=1;glViewport(0,0,W,H);/视口设置glMatrixMode(GL_PROJECTION);/重置坐标系统glLoadIdentity();aspectRati

12、o=(GLfloat)W/(GLfloat)H;if(aspectRatio<=1)/裁剪部分设置glOrtho(-2.5,2.5,-2.5/aspectRatio,2.5/aspectRatio,2.5,-2.5);elseglOrtho(-2.5*aspectRatio,2.5*aspectRatio,-2.5,2.5,2.5,-2.5);glMatrixMode(GL_MODELVIEW);glLoadIdentity();void ProcessKeys(unsigned char ch,int a,int b)if(ch=119)/wy+=0.1;glutPostRedispl

13、ay(); else if(ch=115)/sy-=0.1;glutPostRedisplay(); else if(ch=97)/ax-=0.1;glutPostRedisplay(); else if(ch=100)/dx+=0.1;glutPostRedisplay(); else if(ch=120)/xz-=0.1;glutPostRedisplay(); else if(ch=122)/zz+=0.1;glutPostRedisplay(); else if(ch=43)/+ i+=0.1; j+=0.1; k+=0.1; glutPostRedisplay(); else if(

14、ch=45)/- i-=0.1; j-=0.1; k-=0.1; glutPostRedisplay(); else if(ch=32)/空格键 if(d=0) d=1; else d=0; cout<<d<<endl; /按空格开关旋转void IdleFunc()if(d=1)angle+=1.0f; if(angle=360.0f)angle=0.0f;cout<<angle<<endl;myDisplay(); int _tmain(int argc, char* argv) glutInit(&argc, (char*) arg

15、v); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100,100); glutInitWindowSize(500,500); glutCreateWindow("Hello OpenGL"); glutDisplayFunc(myDisplay); glutReshapeFunc(ChangeSize); glutIdleFunc(IdleFunc); glutKeyboardFunc(ProcessKeys); glutReshapeFunc(Cha

16、ngeSize); glutMainLoop(); return 0;2 系统总体布局系统流程图：本系统是常规的openGL系统，初始化后先设置视角、投影、光照、材质等因素，绘制基本的图形，再通过函数判断键盘输入进行重复绘制，完成基本的平移，缩放，旋转等操作3 系统设计思路在系统设计最初，本来想直接使用默认视角后直接设置光照和平移旋转等功能，但是发现在默认视角下对物体，特别是正方体的三维效果无法很好地观察，因此采用侧视视角然后在对材质的定义上，由于立方体设置比较麻烦，最后决定画一个球体，然后在平移旋转缩放等功能的演示上，直接演示过于简单，就是一个函数的执行，因此决定采取利用键盘控制移动和缩放及旋转的方式。具体操作方法为wsadzx分别控制前后左右上下，space控制开始/停止旋转4 感想和心得 在本次实验中，对我来说最大的问题是正确地理解视点，投影等概念；在默认状态下视角从Z轴正方向看向负方向，对于很多规则物体不旋转的话无法清楚地看到其三维特征，在调整视角的过程中遇到一些问题。然后在加入光照效果的过程中，本来想画多个物体，然后在给物体直接上色再利用光线追踪算法。