Issue with Global Radius-based Surface Descriptor (GRSD)

[nenadpol]

Hi,

I have been trying Global Radius-based Surface Descriptor (GRSD) and have
noticed something in grsd.hpp file.

This is code from line nr 84 to line nr 91.

pcl/features/include/pcl/features/impl/grsd.hpp

Lines 84 to 91 in abf77ff

	// Compute RSD
	pcl::PointCloud<pcl::PrincipalRadiiRSD>::Ptr radii (new pcl::PointCloud<pcl::PrincipalRadiiRSD>());
	pcl::RSDEstimation<PointInT, PointNT, pcl::PrincipalRadiiRSD> rsd;
	rsd.setInputCloud (cloud_downsampled);
	rsd.setSearchSurface (input_);
	rsd.setInputNormals (normals_);
	rsd.setRadiusSearch (std::max (search_radius_, std::sqrt (3.0) * width_ / 2));
	rsd.compute (*radii);

I do not understand line nr 90 (std::max (search_radius_, std::sqrt (3.0) *width_ / 2)) and computing of parameter RadiusSearch.

According to Line 103 in grsd.h setRadiusSearch (double radius) { width_ =search_radius_ = radius; }

search_radius_ and width_ are same values.

My question is what is been computed here : "std::max (search_radius_,std::sqrt (3.0) * width_ / 2)"

Second question/ observation is computing of RSD features in Line 91. If we
take a look at code from line 85 to 91 we kan se that one input parameter is
missing and that is planeRadius.

Since there is no input value, planeRadius gets default value 0.2 ( rsd.h
file line nr.149) and , as result of this , in most cases computed RSD
features have same min and max radius.

This should be corrected.

thanks
Nenad