Get basic CJL.ScatterAlignPose3 functional on standardized code

[dehann]

TAC

get SAP3 functional as simple point to point alignment.

Notes

• separate issue to upgrade ScatterAlignPose3 to also use point normals.

[dehann]

[dehann]

Wip:

• https://github.com/JuliaRobotics/Caesar.jl/pull/874

[dehann]

Common rigid transform function for _PCL and ScatterAlign, working torwards Pose3:

• https://github.com/JuliaRobotics/Caesar.jl/pull/878

[dehann]

Further work for ScatterAlignPose3:

• https://github.com/JuliaRobotics/Caesar.jl/pull/879

[dehann]

Just adding reference alignment solution from completeness:

• http://www.open3d.org/docs/release/tutorial/t_pipelines/t_icp_registration.html?highlight=icp#Multi-Scale-ICP-Example
• http://www.open3d.org/docs/release/tutorial/t_pipelines/t_icp_registration.html?highlight=icp#Point-To-Point-ICP-Registration

[dehann]

To speed things up (and after finding), I'm consolidating the simpleICP.jl implementation. This is the defacto standard. One trick not included in ScatterAlign is to setup the cost function against path normals around each point.

Here is the first piece:

• https://github.com/JuliaRobotics/Caesar.jl/pull/885

and here is what the code does with the two pointclouds from above:

[dehann]

good chunk of this is probably already done with recent work. So the remaining TAC is that ScatterAlign runs through and has a test, but okay if the numerics are not robust.

[dehann]

I recently also added an option for alignments on either

• #927

[dehann]

reminder to consolidate versions across both Caesar and PyCaesar functionality