模块4-2 三维图形投影和消隐
一 实验目的
- 编写三维图形各种变换的投影或消隐算法
二 实验内容
1：自行选择三维物体（不能选长方体），建立坐标系，给定点的三维坐标值，建立边表结构，完成正等轴测投影图。
实验结果如下图所示：
2：自行选择三维物体（不能选长方体），建立坐标系，给定点的三维坐标值，画出三维物体的消隐图。
实验结果如下图所示：
三 程序说明
最终的实验代码如下表所示：
| 2题 |
| // // 程序名称：消隐图 // 功 能：实现预设三维物体的消隐图。 // 编译环境：VS2019，EasyX_20220116 // 最后修改：2022-4-14 #include <graphics.h> #include <conio.h> #include <iostream> #include <stdio.h> #include <stdlib.h> using namespace std; //顶点表 float point[20][4] = { {0,0,150,1},//0 {250,0,150,1},//1 {250,0,50,1},//2 {300,0,50,1},//3 {300,0,0,1},//4 {300,200,0,1},//5 {0,200,0,1},//6 {0,200,100,1},//7 {0,150,100,1},//8 {0,150,150,1},//9 {50,150,150,1},//10 {50,50,150,1},//11 {250,50,150,1},//12 {250,50,50,1},//13 {150,50,50,1},//14 {150,200,50,1},//15 {100,200,100,1},//16 {100,150,100,1},//17 {300,200,50,1},//18 {0,0,0,1}//19 }; //环表 int ring[72] = { //parallel XOY 0,1,12,11,10,9,0,//visible 8,17,16,7,8,//visible 2,3,18,15,14,13,2,//visible 4,19,6,5,4,//invisible //parallel XOZ 1,2,3,4,19,0,1,//invisible 12,13,14,11,12,//visible 10,17,8,9,10,//visible 5,6,7,16,15,18,5,//visible //parallel YOZ 1,2,13,12,1,//visible 0,9,8,7,6,19,0,//invisible 3,4,5,18,3,//visible //slope 11,10,17,16,15,14,11 //visible }; //面表 int surface[12][2] = { //parallel XOY {0,6},{7,11},{12,18},{19,23}, //parallel XOZ {24,30},{31,35},{36,40},{41,47}, //parallel YOZ {48,52},{53,59},{60,64}, //slope {65,71} }; //矩阵乘法，a*b=c，a[m][n]，b[n][q]，c[m][q] void MatrixMultiplication(float a[20][4], float b[4][4], float c[20][4]) { int i = 0, j = 0, k = 0; for (i = 0; i < 20; i++) { for (j = 0; j < 4; j++) { c[i][j] = 0; for (k = 0; k < 4; k++) { c[i][j] = c[i][j] + a[i][k] * b[k][j]; } } } } //主函数 int main() { //float point[20][4] //int ring[72] //int surface[12][2] int i, j, start, end; //正等轴测向量 float zdz[4][4] = { {0.707,0,-0.408,0},{-0.707,0,-0.408,0},{0,0,0.8165,0},{0,0,0,1} }; //备份顶点集 float point1[20][4]; double x1, x2, x3, z1, z2, z3; //E值 double valueE[12]; //矩阵乘法=>正等轴测 MatrixMultiplication(point, zdz, point1); initgraph(1000, 700); //移动x坐标和y坐标 for (i = 0; i < 20; i++) { point1[i][0] = 500 - point1[i][0] * 1.2;//220 point1[i][2] = 350 - point1[i][2] * 1.2;//140 } //求E的值 for (i = 0; i < 12; i++) { j = surface[i][0]; x1 = point1[ring[j]][0]; x2 = point1[ring[j + 1]][0]; x3 = point1[ring[j + 2]][0]; z1 = point1[ring[j]][2]; z2 = point1[ring[j + 1]][2]; z3 = point1[ring[j + 2]][2]; valueE[i] = (z2 - z1) * (x3 - x2) - (x2 - x1) * (z3 - z2); } for (i = 0; i < 12; i++) { if (valueE[i] >= 0) { start = surface[i][0]; end = surface[i][1]; for (j = start; j < end; j++) { line(point1[ring[j]][0], point1[ring[j]][2], point1[ring[j + 1]][0], point1[ring[j + 1]][2]); } } } _getch(); closegraph(); return 0; } |
| 1题 |
| // // 程序名称：正等轴测投影图 // 功 能：实现预设三维物体的正等轴测投影图。 // 编译环境：VS2019，EasyX_20220116 // 最后修改：2022-4-14 #include <graphics.h> #include <conio.h> #include <iostream> #include <math.h> using namespace std; //和分割线之间的距离 const int gap = 50; //预设三维体的点坐标 int X[33] = { 0,0,0,0,0,0,0,0,100,100,0,100,100,100,100,100,100,100,100,0,0,0,0,100,100,100,100,0,0,0,0,100,100 }; int Y[33] = { 0,0,250,250,200,150,0,0,0,0,0,0,150,200,250,250,0,0,150,150,0,150,200,200,150,200,250,250,200,250,250,250,250 }; int Z[33] = { 100,0,0,50,50,100,100,0,0,100,100,100,100,50,50,0,0,100,100,100,100,100,50,50,100,50,50,50,50,50,0,0,50 }; //顶点总数 const int num = 33; //正等轴测图绘制 void fun() { POINT* p = new POINT[num]; for (int i = 0; i < num; i++) { p[i].x = 0.7071 * X[i] - 0.7071 * Y[i] + 500; p[i].y = 0.4082 * X[i] + 0.4082 * Y[i] - 0.8165 * Z[i] + 350; } for (int i = 0; i < num - 1; i++) { setcolor(YELLOW); line(p[i].x, p[i].y, p[i + 1].x, p[i + 1].y); } free(p); } int main() { initgraph(1000, 700); //调用函数 fun(); _getch(); closegraph(); return 0; } |