Point Cloud Alignment (Registration)

What is the best way to align 2 Point Clouds (as shown in the figure below)? I have tried ICP, NDT, Point Cloud Correlation and Feature matching but i didn't get any good results.

figure 
pcshowpair(brushed_SF_PC,brushed_Links_PC)
%% NDT
gridStep = 0.01;
tform = pcregisterndt(brushed_Links_PC,brushed_SF_PC,gridStep);
result = pctransform(brushed_Links_PC,brushed_SF_PC);
figure
pcshowpair(result, brushed_SF_PC);
%% ICP
tformicp = pcregistericp(brushed_Links_PC,brushed_SF_PC,'Extrapolate',true,'Metric', 'pointToPoint','Extrapolate',true);
ptCloudAligned = pctransform(brushed_Links_PC,tformicp);
mergeSize = 0.015;
ptCloudScene = pcmerge(brushed_SF_PC,brushed_Links_PC, mergeSize);
% figure
pcshow(ptCloudScene, 'VerticalAxis','Y', 'VerticalAxisDir', 'Down')

Answer 1

[Image Analyst]

Not an easy question to answer or solve. But you can start here:

https://en.wikipedia.org/wiki/Point_set_registration