Added Conditions for Slerp vs Squad interpolation

[sdhar04]

🎉 New feature

Closes #568

Summary

I have added conditionals for using the Slerp algorithm when the difference in final and initial orientations falls within a threshold. Otherwise Squad is invoked.

Test it

You can open Gazebo and run the bash script I have added in gz-math/test which publishes a new position and orientation to the camera every 2 seconds.

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

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[ahcorde]

Why is this file required? It looks like an example, a test required some expectations or asserts

[sdhar04]

The issue asks for smoother movements which are brought about by Slerp under the threshold, while Squad works just fine above it. I don’t know how to assert if a given interpolation is smooth or not, so I added this file for anyone to check the movements themselves.

[sdhar04]

@ahcorde I have removed the bash script

[mjcarroll]

@sdhar04 Can you address these lint issues?

  /github/workspace/src/RotationSpline.cc:95:  Line ends in whitespace.  Consider deleting these extra spaces.  [whitespace/end_of_line] [4]
  /github/workspace/src/RotationSpline.cc:98:  Line ends in whitespace.  Consider deleting these extra spaces.  [whitespace/end_of_line] [4]
  /github/workspace/src/RotationSpline.cc:102:  Line ends in whitespace.  Consider deleting these extra spaces.  [whitespace/end_of_line] [4]
  /github/workspace/src/RotationSpline.cc:104:  Missing spaces around <  [whitespace/operators] [3]
  /github/workspace/src/RotationSpline.cc:108:  Line ends in whitespace.  Consider deleting these extra spaces.  [whitespace/end_of_line] [4]

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 94.11%. Comparing base (91c73b9) to head (7dfe977).

❗ Current head 7dfe977 differs from pull request most recent head cf8b74c. Consider uploading reports for the commit cf8b74c to get more accurate results

Files	Patch %	Lines
src/RotationSpline.cc	87.50%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           gz-math7     #577      +/-   ##
============================================
- Coverage     94.11%   94.11%   -0.01%     
============================================
  Files           146      146              
  Lines          9809     9816       +7     
============================================
+ Hits           9232     9238       +6     
- Misses          577      578       +1     

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[sdhar04]

@mjcarroll @azeey I have addressed the lint issues and reduced the scope of 2 variables only required for Squad interpolation. However, the tests don't seem to invoke the cases where Slerp is used, hence the codecov warnings. I have a bash script I used during testing to supply target orientations and both algorithms are used in my test cases (I checked by printing which one was invoked), with the interpolation being desirably smooth.
I have seen the tests and they seem to check for the midpoint of an interpolation. I don't know what the midpoint would be for a given Slerp interpolation, although I could try to figure things out by printing values while interpolating. Please guide me regarding what to do now. Do I need to change the RotationSpline_TEST.cc file only?

[ahcorde]

@azeey or @scpeters what do you think about this ?

[ahcorde]

remove this

[ahcorde]

Suggested change

	*/
	#include "gz/math/Quaternion.hh"
	#include "gz/math/RotationSpline.hh"
	#include "cmath"
	*/
	#include <cmath>
	#include "gz/math/Quaternion.hh"
	#include "gz/math/RotationSpline.hh"

[arjo129]

Hi @sdhar04 , was wondering what the status on this was. Do we intend shipping this change with ionic (code freeze 26/8)? If we can't come to a consensus by then I will remove the beta label (I personally would prefer seeing it in this release).

[arjo129]

Hi @sdhar04 as we haven't heard back from you, I'm removing the beta label. @ahcorde's suggestions still apply.