OpenGL环境下PLY三维模型的读入与显示的源码

#include <GL/glut.h> #include <cstdio> #include <cmath> //声明结构体用于处理三维点云数据 typedef struct VERTEX_3D { float x; float y; float z; } VERTEX3D; //三角 typedef struct _TRIANGLE { int A;//Index of vertex 0 int B;//Index of vertex 1 int C;//Index of vertex 2 } TRIANGLE; VERTEX3D *g_vet; VERTEX3D *g_norm; VERTEX3D *g_color; TRIANGLE *triPatch; float g_rotx = 20.0f, g_roty = 30.0f, g_rotz = 0.0f; float g_modelPos[3] = {0, 0, -15.0f}; float g_scale = 10.0f; const float g_lightPos[] = { 1.0f, 1.0f, 1.0f, 0.0f }; char g_strModelName[512] = "plant.ply"; /*Problem happens when left the [512] being empty []*/ int g_nVerticesNumber;//顶点数 int g_nFacesNumber;//面数 //归一化 void Normalize(VERTEX3D &v) { double length = sqrt(v.x*v.x+v.y*v.y+v.z*v.z); if(length!=0) { v.x = v.x/length; v.y = v.y/length; v.z = v.z/length; } } //获取最小最大值 void GetMinMax(VERTEX3D &vMin, VERTEX3D &vMax, VERTEX3D v) { if(v.x < vMin.x ) vMin.x = v.x; if(v.y < vMin.y ) vMin.y = v.y; if(v.z < vMin.z ) vMin.z = v.z; if(v.x > vMax.x ) vMax.x = v.x; if(v.y > vMax.y ) vMax.y = v.y; if(v.z > vMax.z ) vMax.z = v.z; } //格式化几何图形 void FormatGeometry(VERTEX3D &v, VERTEX3D vMin, VERTEX3D vMax, float scale) { v.x = scale*(v.x - 0.5*(vMin.x + vMax.x)); v.y = scale*(v.y - 0.5*(vMin.y + vMax.y)); v.z = scale*(v.z - 0.5*(vMin.z + vMax.z)); } //加载网格层 void LoadMeshPLY(char *FileName) { int i, j; VERTEX3D vMin, vMax; char strBuff[512]; char type[512] = ""; bool bStartPropertyCount = true;//开始属性计数 float alpha; vMin.x = vMin.y = vMin.z = 99999.0; vMax.x = vMax.y = vMax.z = -99999.0; FILE* fp=fopen(FileName,"r"); if (fp==NULL)//文件不存在 { printf("ERROR: unable to open model [%s]!\n",FileName); exit(0); } //读文件 fgets(strBuff, 256, fp); fgets(strBuff, 256, fp); fgets(strBuff, 256, fp); fscanf(fp, "element vertex %d\n", &g_nVerticesNumber); j = 0; while (strcmp(type,"element")!=0) { fgets(strBuff, 256, fp); i = 0; while(strBuff[i]!='\0'&&strBuff[i]!=' '&&strBuff[i]!='\n') { type[i] = strBuff[i]; i++; } if (bStartPropertyCount&&strcmp(type,"property")==0) j++; else bStartPropertyCount = false; type[i] = '\0'; } sscanf(strBuff, "element face %d\n", &g_nFacesNumber); printf("Number of Triangles: %d\n", g_nFacesNumber); fgets(strBuff, 256, fp); fgets(strBuff, 256, fp); //fgets(strBuff, 256, fp);多读的一点 //Allocate the triangle array g_vet = new VERTEX3D[g_nVerticesNumber]; g_norm = new VERTEX3D[g_nVerticesNumber]; g_color = new VERTEX3D[g_nVerticesNumber]; triPatch = new TRIANGLE[g_nFacesNumber]; //Read in the triangles for (i=0; i<g_nVerticesNumber; i++) { if (j==3) fscanf(fp, "%f %f %f", &g_vet[i].x, &g_vet[i].y, &g_vet[i].z); else if(j==6) fscanf(fp, "%f %f %f %f %f %f", &g_vet[i].x, &g_vet[i].y, &g_vet[i].z, &g_norm[i].x, &g_norm[i].y, &g_norm[i].z); else if (j==7) fscanf(fp, "%f %f %f %f %f %f %f", &g_vet[i].x, &g_vet[i].y, &g_vet[i].z, &g_color[i].x, &g_color[i].y, &g_color[i].z, &alpha); else if (j==10) fscanf(fp, "%f %f %f %f %f %f %f %f %f %f", &g_vet[i].x, &g_vet[i].y, &g_vet[i].z, &g_norm[i].x, &g_norm[i].y, &g_norm[i].z, &g_color[i].x, &g_color[i].y, &g_color[i].z, &alpha); else { printf("Warning: the viewer cann't read the colors of models\n"); exit(1); } GetMinMax(vMin, vMax, g_vet[i]); Normalize(g_norm[i]); } int tmp; for (i=0; i<g_nFacesNumber; i++) { fscanf(fp, "%d %d %d %d",&tmp , &triPatch[i].A, &triPatch[i].B, &triPatch[i].C); } if((vMax.x - vMin.x) > (vMax.y-vMin.y)) { if ((vMax.x - vMin.x) > (vMax.z - vMin.z)) g_scale = g_scale/(vMax.x - vMin.x); else g_scale = g_scale/(vMax.z - vMin.z); } else { if ((vMax.y - vMin.y) > (vMax.z - vMin.z)) g_scale = g_scale/(vMax.y - vMin.y); else g_scale = g_scale/(vMax.z - vMin.z); } for (i=0; i<g_nVerticesNumber; i++) FormatGeometry(g_vet[i], vMin, vMax, g_scale); fclose(fp); } //绘图顶点 void DrawVertices() { int i; //glEnable(GL_LIGHTING); glPointSize(2.0); glBegin(GL_TRIANGLES); for(i=0;i<g_nFacesNumber;i++) { glBegin(GL_TRIANGLES); //glBegin();创建元素的类型，比如：点，线等。 //GL_POINTS：把每个顶点作为一个点进行处理，顶点n定义了点n，绘制N个点。 //GL_LINES： 把每个顶点作为一个独立的线段，顶点2n-1和2n之间定义了n条线段，绘制N/2条线段 //GL_LINE_STRIP：绘制从第一个顶点到最后一个顶点依次相连的一组线段，第n和n+1个顶点定义了线段n，绘制n-1条线段。 //GL_LINE_LOOP： 绘制从第一个顶点到最后一个顶点依次相连的一组线段，然后最后一个顶点和第一个顶点相连，第n和n+1个顶点定义了线段n，绘制n条线段。 //GL_TRIANGLES： 把每个顶点作为一个独立的三角形，顶点3n-2，3n-1和3n定义了第n个三角形，绘制了N/3个三角形。 //GL_TRIANGLE_STPIP：绘制一组相连的三角形，对于奇数n，顶点n，n+1，和n+2定义了第n个三角形；对于偶数n，顶点n+1，n和n+2定义了第n个三角形，绘制N-2个三角 形。 //GL_QUADS: 绘制由四个顶点组成的一组单独的四边形。顶点4n-3，4n-2，4n-1和4n定义了第n个四边形。绘制了N/4个四边形。 //GL_QUAD_STRIP：绘制一组相连的四边形。每个四边形是由一对顶点及其后给定的一对顶点共同确定的。顶点2n-1，2n，2n+2和2n+1定义了第n个四边形，绘制了N/2-1个 四边形。 //GL_POLYGON： 绘制了一个凸多边形。顶点1到n定义了这个多边形。 glNormal3f(g_norm[triPatch[i].A].x,g_norm[triPatch[i].A].y,g_norm[triPatch[i].A].z); glNormal3f(g_norm[triPatch[i].B].x,g_norm[triPatch[i].B].y,g_norm[triPatch[i].B].z); glNormal3f(g_norm[triPatch[i].C].x,g_norm[triPatch[i].C].y,g_norm[triPatch[i].C].z); glColor3f(g_color[triPatch[i].A].x,g_color[triPatch[i].A].y,g_color[triPatch[i].A].z); glColor3f(g_color[triPatch[i].B].x,g_color[triPatch[i].B].y,g_color[triPatch[i].B].z); glColor3f(g_color[triPatch[i].C].x,g_color[triPatch[i].C].y,g_color[triPatch[i].C].z); glVertex3f(g_vet[triPatch[i].A].x,g_vet[triPatch[i].A].y,g_vet[triPatch[i].A].z); glVertex3f(g_vet[triPatch[i].B].x,g_vet[triPatch[i].B].y,g_vet[triPatch[i].B].z); glVertex3f(g_vet[triPatch[i].C].x,g_vet[triPatch[i].C].y,g_vet[triPatch[i].C].z); glEnd(); } //glEnd(); } static void resize(int width, int height) { const float ar = (float) width / (float) height; glViewport(0, 0, width, height);//0,0指定了窗口的左下角位置。 //width,height表示视口矩形的宽度和高度，根据窗口的实时变化重绘窗口。 glMatrixMode(GL_PROJECTION);//将当前矩阵指定为投影矩阵 glLoadIdentity();//把矩阵设为单位矩阵 gluPerspective(45, ar, 1.0, 100.0);//指定要观察的视景体在世界坐标系中的具体大小 glMatrixMode(GL_MODELVIEW);//指定当前要操作的矩阵， GL_MODELVIEW模型视图 glLoadIdentity() ; } static void display(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity() ; glTranslatef(g_modelPos[0], g_modelPos[1], g_modelPos[2]); //定义一个平移矩阵，该矩阵与当前矩阵相乘，使后续的图形相对与当前所在的屏幕位置。进行平移变换。 glRotatef(g_rotx, 1.0, 0.0, 0.0); glRotatef(g_roty, 0.0, 1.0, 0.0); glRotatef(g_rotz, 0.0, 0.0, 1.0); DrawVertices(); glutSwapBuffers(); } static void key(unsigned char key