Populate default material for model

[ntfshard]

🦟 Bug fix

Fixes #

Summary

Adding model with Entity Tree gui plugin, or in sdf w/o material won't creating a material entity in ECM. Object will looks flat and it's not possible to change material properties in gui. Populating default material will allow to configure it in gui.

Behaviour changing: before color of model was white and after this change it will be black. According to SDF specification http://sdformat.org/spec?elem=material&ver=1.9 it's correct behaviour. So technically it's a fix

Before (no Material submenu):

After:

I checked this change on gz-sim8 branch (I already had all libraries compiled); I guess it should be the same on gz-sim9

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
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[caguero]

Small suggestion to simplify the logic:

sdf::Material visualMaterial;
if (_visual->Material())
  visualMaterial = *_visual->Material();

this->dataPtr->ecm->CreateComponent(visualEntity,
  components::Material(visualMaterial));

[ntfshard]

Lifetime of visualMaterial will be much bigger than it needed. But if you insist I can do it

[ntfshard]

Not sure about logic simplification especially with such giant if scope, but I changed

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.02%. Comparing base (47a2580) to head (14976e9).

Additional details and impacted files

@@             Coverage Diff             @@
##           gz-sim9    #3009      +/-   ##
===========================================
- Coverage    69.07%   69.02%   -0.05%     
===========================================
  Files          347      347              
  Lines        34038    34039       +1     
===========================================
- Hits         23512    23496      -16     
- Misses       10526    10543      +17     

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[azeey]

This looks good to me. Even though it's a behavior change, I don't think anyone would be relying on the old behavior. However, would you mind targetting this to main? We'll backport to gz-sim9 once it's merged.

[ntfshard]

This looks good to me. Even though it's a behavior change, I don't think anyone would be relying on the old behavior. However, would you mind targetting this to main? We'll backport to gz-sim9 once it's merged.

I will create a separate PR in main, changing base is not working well

One test relied on this colour. But seems according to SDF it should be black

[ntfshard]

Closing this PR due to #3139 created to main