vtkPolyData 示例代码
作者：互联网
本文主要介绍使用使用一系列的点生成各种 PolyData 的过程。
我们首先生成螺旋曲线， 这个比较简单。 使用一些简单的数据知识就可以办到：
1 /********************************************
2 * 描述：
3 * 构建形成线条的所有点集。
4 * 参数列表：
5 * count - 线条所在坐标三个维度的分辨率。
6 * 返回值：
7 * 线条的点集。
8 *******************************************/
9 std::vector < vtkPoint > BuildPoints ( int count )
10 {
11 std::vector < vtkPoint > points;
12
13 for ( int y = 0; y < count; y++ )
14 {
15 vtkPoint point;
16 point.x = radians * cos ( y / vtkMath::Pi() );
17 point.y = y;
18 point.z = radians * sin ( y / vtkMath::Pi() );
19 point.radians = 3;
20 points.push_back ( point );
21 }
22
23 return points;
24 }
有了点之后，我们把这些点连接成线。
1 /********************************************
2 * 描述：将点连成线
3 * 参数列表：
4 * points - 点集.
5 * 返回值：
6 * 用 vtkPolyData 表示的线条。
7 *******************************************/
8 vtkPolyData * BuildLines ( std::vector < vtkPoint > & points )
9 {
10 vtkNew <vtkPoints> polydataPoints;
11 vtkNew < vtkCellArray > cells;
12
13 int count = points.size();
14 for ( int i=0; i<count; i++ )
15 {
16 polydataPoints->InsertNextPoint ( points[i].x, points[i].y, points[i].z );
17 }
18
19 for ( int i=0; i<count-1; i++ )
20 {
21 vtkIdType pts[2] = { i, i+1 };
22 cells->InsertNextCell ( 2, pts );
23 }
24
25 vtkPolyData * polyData = vtkPolyData::New ();
26 polyData->SetPoints ( polydataPoints );
27 polyData->SetLines ( cells );
28
29 return polyData;
30 }
然后我们就可以把这个线显示出来：如图
之后我们继续以每个点为圆心作圆。
1 vtkPolyData * BuildCircles ( std::vector < vtkPoint > & points, int resolution )
2 {
3 std::vector < vtkPoint > circlePoints = BuildCirclePoints ( points, resolution );
4
5 vtkNew < vtkAppendPolyData > append;
6 int count = circlePoints.size();
7
8 for ( int i=0; i<count; i+=resolution )
9 {
10 vtkNew < vtkPoints > vPoints;
11 vtkNew < vtkCellArray > cells;
12
13 for ( int j=0; j<resolution; j++ )
14 {
15 int idx = i+j;
16 vPoints->InsertNextPoint ( circlePoints[idx].x, circlePoints[idx].y, circlePoints[idx].z );
17 }
18
19 for ( int j=0; j<resolution; j++ )
20 {
21 int n = j+1;
22 if ( n >= resolution )
23 n = 0;
24
25 vtkIdType pts[2] = {j, n};
26 cells->InsertNextCell ( 2, pts );
27 }
28
29 vtkNew < vtkPolyData > polyData;
30 polyData->SetPoints ( vPoints );
31 polyData->SetLines ( cells );
32 append->AddInputData ( polyData );
33 }
34
35 //
36 append->Update ();
37 vtkPolyData * retPolyData = append->GetOutput ();
38 retPolyData->Register ( NULL );
39
40 //
41 return retPolyData;
42 }
将它返回的 retPolyData 显示出来就是下面的样子。
最后，我们只需连接上下两个圆的点，形成面片，就可以生成三维表面了。
1 /********************************************
2 * 描述： 构建表面。
3 * 参数列表：
4 * points - 点集，每一个点都是一个圆的圆心。
5 * resolution - 圆是由一系列的线段构成， resolution 指定线段数量。
6 * 返回值：
7 * 返回所有圆构成的表面.
8 *******************************************/
9 vtkPolyData * BuildSurface ( std::vector < vtkPoint > & points, int resolution )
10 {
11 std::vector < vtkPoint > circlePoints = BuildCirclePoints ( points, resolution );
12
13 vtkNew < vtkAppendPolyData > append;
14 int count = circlePoints.size() - resolution;
15
16 for ( int i=0; i<count; i+=resolution )
17 {
18 for ( int j=0; j<resolution; j++ )
19 {
20 vtkNew < vtkPoints > vPoints;
21 vtkNew < vtkCellArray > cells;
22
23 bool bflag = j == ( resolution-1 );
24
25 int idx = j+i;
26 int lt = idx;
27 int rt = idx + 1;
28 int rd = rt + resolution;
29 int ld = lt + resolution;
30
31 if ( bflag )
32 {
33 rt = i;
34 rd = i + resolution;
35 }
36
37
38 vPoints->InsertNextPoint ( circlePoints[lt].x, circlePoints[lt].y, circlePoints[lt].z );
39 vPoints->InsertNextPoint ( circlePoints[rt].x, circlePoints[rt].y, circlePoints[rt].z );
40 vPoints->InsertNextPoint ( circlePoints[rd].x, circlePoints[rd].y, circlePoints[rd].z);
41 vPoints->InsertNextPoint ( circlePoints[ld].x, circlePoints[ld].y, circlePoints[ld].z);
42
43 //
44 vtkNew < vtkQuad > quad;
45 for ( int c=0; c<4; c++ )
46 {
47 quad->GetPointIds()->SetId ( c, c );
48 }
49 cells->InsertNextCell ( quad );
50
51 //
52 vtkNew < vtkPolyData > polyData;
53 polyData->SetPoints ( vPoints );
54 polyData->SetPolys ( cells );
55 append->AddInputData ( polyData );
56 }
57 }
58
59 //
60 append->Update ();
61 vtkPolyData * retPolyData = append->GetOutput ();
62 retPolyData->Register ( NULL );
63
64 //
65 return retPolyData;
66 }
把这里返回的 PolyData 显示出来就是下面的样子：
标签：polyData,circlePoints,示例,int,代码,vtkPolyData,points,resolution 来源： https://www.cnblogs.com/biaohuang/p/14613742.html