[test] Unit test design for poisson surface reconstruction

[shrijitsingh99]

Context

The poisson surface reconstruction algorithm needs a new unit test. The currently existing test is not very robust and has been made using some unknown empirical readings.

Current Test:

pcl/test/surface/test_poisson.cpp

Lines 67 to 90 in 665a58c

	Poisson<PointNormal> poisson;
	poisson.setInputCloud (cloud_with_normals);
	PolygonMesh mesh;
	poisson.reconstruct (mesh);
	// io::saveVTKFile ("bunny_poisson.vtk", mesh);
	ASSERT_EQ (mesh.polygons.size (), 1051);
	// All polygons should be triangles
	for (std::size_t i = 0; i < mesh.polygons.size (); ++i)
	EXPECT_EQ (mesh.polygons[i].vertices.size (), 3);
	EXPECT_EQ (mesh.polygons[10].vertices[0], 121);
	EXPECT_EQ (mesh.polygons[10].vertices[1], 120);
	EXPECT_EQ (mesh.polygons[10].vertices[2], 23);
	EXPECT_EQ (mesh.polygons[200].vertices[0], 130);
	EXPECT_EQ (mesh.polygons[200].vertices[1], 119);
	EXPECT_EQ (mesh.polygons[200].vertices[2], 131);
	EXPECT_EQ (mesh.polygons[1000].vertices[0], 521);
	EXPECT_EQ (mesh.polygons[1000].vertices[1], 516);
	EXPECT_EQ (mesh.polygons[1000].vertices[2], 517);

Expected behavior

A new robust test is needed, which is deterministic and is hopefully not based on empirical readings.