PCL自定义点类型

除了pcl已定义点类型，参考http://www.cnblogs.com/li-yao7758258/p/6433445.html

很多时候都需要自定义所需点类型，定义方法如下

以下例子是创建新的点类型，数据中包含X,Y,Z,PC1，PC2，meanPC（平均曲率），作为参考

step 1 新建myPointType.h

#define PCL_NO_PRECOMPILE

#ifndef MYPOINTTYPE_H
#define MYPOINTTYPE_H

#include <pcl/point_types.h>

struct XYZ_CURVA
{
	PCL_ADD_POINT4D;
	union
	{
		float coordinate[3];
		struct
		{
			float x;
			float y;
			float z;
		};
	};
	float pc1;
	float pc2;
	float mean_pc;
	EIGEN_MAKE_ALIGNED_OPERATOR_NEW;
}EIGEN_ALIGN16;


POINT_CLOUD_REGISTER_POINT_STRUCT(XYZ_CURVA,// 注册点类型宏
	(float, x, x)
	(float, y, y)
	(float, z, z)
	(float, pc1, pc1)
	(float, pc2, pc2)
	(float, mean_pc, mean_pc)
	)

#endif

step 2 cpp中使用
法线和曲率计算参见官网法线例子，曲率计算例子如下（并不是真正数学意义上的曲率）

pcl::PointCloud<pcl::Normal>::Ptr cloud_with_normals;
	pcl::PointCloud<pcl::PrincipalCurvatures>::Ptr principal_curvatures;
	pcl::NormalEstimation<pcl::PointXYZ, pcl::Normal> normal_estimation;

	normal_estimation.setInputCloud(cloud);
	pcl::search::KdTree<pcl::PointXYZ>::Ptr tree(new pcl::search::KdTree<pcl::PointXYZ>);
	normal_estimation.setSearchMethod(tree);
	//适合本实验数据的k值
	normal_estimation.setKSearch(60);
	normal_estimation.compute(*cloud_with_normals);
	// Setup the principal curvatures computation
	pcl::PrincipalCurvaturesEstimation<pcl::PointXYZ, pcl::Normal, pcl::PrincipalCurvatures> principal_curvatures_estimation;

	// Provide the original point cloud (without normals)
	principal_curvatures_estimation.setInputCloud(cloud);
	// Provide the point cloud with normals
	principal_curvatures_estimation.setInputNormals(cloud_with_normals);
	// Use the same KdTree from the normal estimation
	principal_curvatures_estimation.setSearchMethod(tree);
	principal_curvatures_estimation.setKSearch(60);
	// Actually compute the principal curvatures
	principal_curvatures_estimation.compute(*principal_curvatures);
	pcl::io::savePCDFile("temp/curva_out.pcd", *principal_curvatures);
	pcl::io::savePCDFile("temp/normal_out.pcd", *cloud_with_normals);

将每个点坐标以及计算好的数据保存至新文件

int size = cloud->size();
	pcl::PointCloud<XYZ_CURVA> xyz_curva;
	xyz_curva.points.resize(size);
	xyz_curva.width = size;
	xyz_curva.height = 1;
	for (int i = 0; i < size; i++)
	{
		xyz_curva.points[i].x = cloud->points[i].x;
		xyz_curva.points[i].y = cloud->points[i].y;
		xyz_curva.points[i].z = cloud->points[i].z;

		xyz_curva.points[i].pc1 = principal_curvatures->points[i].pc1;
		xyz_curva.points[i].pc2 = principal_curvatures->points[i].pc2;
		xyz_curva.points[i].mean_pc = (principal_curvatures->points[i].pc1 + principal_curvatures->points[i].pc2)/2;
	}
	pcl::io::savePCDFile("temp/test.pcd", xyz_curva);

存在问题：

IntelliSense:  常量表达式中不允许该运算符 myPointType.h （但是最终结果不受影响，编译器或者版本的问题maybe）