I've searched around and its not clear which version of the SDF spec (1.4-1.6) corresponds to Gazebo7, etc. My Ubuntu 16.04 package manager says I have SDFormat4 install, further confusing me. Why isn't the binary release matching the spec version?
From the Gazebo changelog, it seems Gazebo7 uses 1.6, but its not 100% clear. Perhaps this can be added to the documentation/website somewhere?
The SDF spec version supported has nothing to do with the versioning of SDFormat package. SDF is a format specification and as such, it has it's own versions: 1.4, 1.5, 1.6 (as of today). In debian/ubuntu it is distributed with the package name of sdformat-sdf and it is not strictly related to a particular version of the rest of SDFormat packages although all them come from the same source tarball.
SDFormat is a C++ software which works with the SDF specification. It follows semantic versioning and major versions corresspond to changes in ABI. It versioning scheme has nothing to do with the SDF protocol supported.
The confusion could come from the fact that both are hosted in the same repository and are installed together. In Gazebo we use the dependency directly on SDFormat since it would bring the SDF protocol needed by a particular version (plus the expected API, etc).
On http://sdformat.org/ there should be a table comparing Gazebo version to SDFormat verison like there is on gazebosim.org. Maybe a link to more details (the ones you just provided here). Where can I open a ticket for this documentation request?
I started something like this on this pull request to gazebo tutorials: https://bitbucket.org/osrf/gazebo_tutorials/pull-requests/386/split-step-to-install-dependencies-from/diff @jose-luis-rivero, what do you think of adding information about the SDF spec there too? Feel free to commit directly to that branch if you wish.
I've added some information to that PR: https://bitbucket.org/osrf/gazebo_tutorials/commits/f53ab05209d7df1668116533800e8c0042f715cf?at=default , hopefully it will help with the problem. We could also consider to add the information about SDF vs SDFormat in the sdformat.org front page.
Asked: 2017-02-16 01:13:38 -0500
Seen: 4,909 times
Last updated: Feb 21 '17
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This is a common source of confusion, see this question for example: http://answers.gazebosim.org/question/12544/sdf-versions-unable-to-convert-from-sdf-version-15-to-14/
Gazebo7 should support SDF 1.6 but I cannot find a clear answer by simply looking at dpkg, changelogs or sdformat.org
How can we improve this for others?