opencvsharp点云转网格

在OpenCvSharp中，点云与网格之间的转换可以使用pcl库（Point Cloud Library）来实现。具体步骤如下：

1. 将点云数据转换为pcl中的PointCloud类对象。

using PointCloud = PCL.PointCloud<PCL.PointXYZ>;

PointCloud cloud = new PointCloud();
cloud.Width = pointCloud.Width;
cloud.Height = pointCloud.Height;
cloud.Points.Capacity = pointCloud.Width * pointCloud.Height;

for (int i = 0; i < pointCloud.Height; i++)
{
    for (int j = 0; j < pointCloud.Width; j++)
    {
        Vector3 point = pointCloud[i, j];
        cloud.Points.Add(new PCL.PointXYZ(point.X, point.Y, point.Z));
    }
}

其中，pointCloud是一个Mat对象，存储了点云数据。

2. 使用pcl库中的Poisson方法将点云数据转换为网格数据。

using PolygonMesh = PCL.PolygonMesh;

PolygonMesh mesh = new PolygonMesh();
PCL.Poisson<PointXYZ, Normal> poisson = new PCL.Poisson<PointXYZ, Normal>();

poisson.SetDepth(8);
poisson.SetSolverDivide(8);
poisson.InputCloud = cloud;
poisson.Reconstruct(mesh);

3. 将pcl中的PolygonMesh对象转换为OpenCvSharp中的网格对象。

using Mesh = OpenCvSharp.Mesh;

Mesh opencvMesh = new Mesh();

int vertexCount = mesh.Cloud.Points.Count;
int triangleCount = mesh.Polygons.Count;

opencvMesh.Vertices.SetSize(vertexCount);
opencvMesh.Triangles.SetSize(triangleCount);

for (int i = 0; i < vertexCount; i++)
{
    PCL.PointXYZ pclVertex = mesh.Cloud.Points[i];
    Vector3 opencvVertex = new Vector3((float)pclVertex.X, (float)pclVertex.Y, (float)pclVertex.Z);
    opencvMesh.Vertices.SetVec3fAt(i, opencvVertex);
}

for (int i = 0; i < triangleCount; i++)
{
    PCL.Vertices vertices = mesh.Polygons[i].Vertices;
    opencvMesh.Triangles.SetPointAt(i, 0, vertices[0]);
    opencvMesh.Triangles.SetPointAt(i, 1, vertices[1]);
    opencvMesh.Triangles.SetPointAt(i, 2, vertices[2]);
}

其中，pcl中的PolygonMesh对象存储了三角形网格的顶点和索引信息，可以通过Vertices和Polygons属性进行访问。OpenCvSharp中的Mesh对象类似，可以通过Vertices和Triangles属性进行访问。