Duplicate material entries in URDF causes issue to joint_state_publisher

[guihomework]

When starting a BiManual setup with agni_description (typically sfb setup) multiple material descriptions are added to the full robot_description, probably since this addition

agni_robots/agni_description/robots/shadow_hand.urdf.xacro

Line 4 in d6be5be

<xacro:include filename="$(find sr_description)/materials.urdf.xacro" />

which causes issues for the joint_state_publisher required in the jsmerger.launch due to duplicate materials (even triple since sfb.urdf.xacro used to load materials once for the entire setup)

/vol/....../agni_deploy/launch/jsmerger.launch

[ERROR] [1658945140.050018284]: material 'Blue' is not unique.

standalone hands never had issues with missing material in the past, even when started in simulation, so I am not sure why this addition was needed now.

[rhaschke]

Is this just a cosmetic issue, i.e. did everything still work as expected and you just want to get rid of the error messages (which actually should be warnings only)?

[guihomework]

our vdemo component jsmerger fails the "check" and stops, so the error is probably significant, because when the duplicate entries are removed, the vdemo check passes. I did not look further.

[rhaschke]

For now, I resetted melodic-devel to its old state. Looks like I rebased my noetic-devel changes to melodic-devel to try them there as well. But I didn't finish this work yet...

[rhaschke]

There was another duplicate material (dark_grey) in ubi-noetic-devel branch (due to this commit), which I reverted too now.
TODO: Update Shadow sources to latest release.