USD to SDF: Initial commit

[ahcorde]

Signed-off-by: ahcorde [email protected]

🎉 New feature

Summary

This PR is the initial commit to support the conversion between USD to SDF.

The two classes included here allow to load stage and get the relevant data such us:

• upaxis
• meterperunit
• materials

Test it

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

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.

[codecov-commenter]

Codecov Report

Merging #827 (0765a26) into sdf12 (41d370d) will decrease coverage by 0.45%.
The diff coverage is 67.10%.

❗ Current head 0765a26 differs from pull request most recent head bf579ed. Consider uploading reports for the commit bf579ed to get more accurate results

@@            Coverage Diff             @@
##            sdf12     #827      +/-   ##
==========================================
- Coverage   88.65%   88.19%   -0.46%     
==========================================
  Files          92       95       +3     
  Lines       14221    14525     +304     
==========================================
+ Hits        12607    12811     +204     
- Misses       1614     1714     +100     

Impacted Files	Coverage Δ
usd/src/usd_parser/USDMaterial.cc	62.91% <62.91%> (ø)
usd/src/usd_parser/USDData.cc	63.55% <63.55%> (ø)
usd/src/usd_parser/USDStage.cc	97.14% <97.14%> (ø)

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[adlarkin]

I noticed that the USD -> SDF converter has a different file structure than the SDF -> USD converter. The USD -> SDF converter has headers in usd/include/sdf/usd_parser instead of usd/include/sdf/usd, and source files are in usd/src/usd_parser instead of usd/src. I think it makes sense to separate the USD -> SDF and SDF -> USD header/source files, but what if we used the following file structure for both converters so that they are more aligned:

• Have a usd/include/sdf/usd directory, which is the "top level" header directory. SDF -> USD converter headers can be in the usd/include/sdf/usd/sdf_parser directory, and USD -> SDF converter headers can be in the usd/include/sdf/usd/usd_parser.
• Keep a usd/src directory, which is the "top level" source directory. SDF -> USD converter sources can be in the usd/src/sdf_parser directory, and USD -> SDF converter sources can be in the usd/src/usd_parser directory.

Another option would be to have both converter header files in usd/include/sdf/usd, and both converter source files in usd/src, but this could make it difficult for users to know which files are associated with which parser.

If we decide to re-work the file structure to what I proposed above, then we would need to update the file structure in #817 before merging it.

File structure has been reworked in 2088f1e

[adlarkin]

I haven't reviewed all of the files yet, but I do have a few questions:

1. test/usd/empty_file.usda is not used. Can this file be removed?
2. Can tests be added for the API in UsdMaterial.hh?

[ahcorde]

I haven't reviewed all of the files yet, but I do have a few questions:

1. test/usd/empty_file.usda is not used. Can this file be removed?
2. Can tests be added for the API in UsdMaterial.hh?

1. f77cd78
2. 0f34f61

[ahcorde]

@osrf-jenkins retest this please

[ahcorde]

@azeey do you mind to take another look to this pull request?

[azeey]

Just a few more minor comments. LGTM otherwise.

[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-ignition-releases-2022-04-13-fortress-edifice/1367/1