Clarify min and max temperature of thermal camera

[mjacobse]

This is an attempt to improve the documentation of the <min_temp>, <max_temp> and <resolution> tags in the thermal camera documentation.

After reading the description of <min_temp> and <max_temp> in the thermal camera tutorial I expected an output camera image value of 0 to mean <min_temp> Kelvin and a value of 2^bitDepth - 1 to mean <max_temp> Kelvin, so I was surprised to find out that that was not the case. Granted, the presence of the <resolution> tag did not really fit this mental model. It is also possible that this confusion was amplified by bugs that are now fixed (gazebosim/gz-rendering#1133 and gazebosim/gz-rendering#1138).

Nevertheless I tried to rephrase the descriptions a bit in an attempt to minimize the potential for confusion in the future. Hopefully it makes some sense to people other than me.

Checklist

• Signed all commits for DCO
• Updated documentation (as needed)

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.

[iche033]

great thanks for improving the documentation!

[mjacobse]

Would it be possible to port this to other release versions too? I see that https://gazebosim.org/api/sensors/8/thermalcameraigngazebo.html has the updated description, but https://gazebosim.org/api/sensors/9/thermalcameraigngazebo.html and https://gazebosim.org/api/sensors/6/thermalcameraigngazebo.html (which comes up for me when I google "gazebo thermal camera") still have the old one.

[iche033]

@Mergifyio backport ign-sensors6

[mergify]

backport ign-sensors6

✅ Backports have been created

Details

• #539 Clarify min and max temperature of thermal camera (backport #523) has been created for branch ign-sensors6

[iche033]

Would it be possible to port this to other release versions too? I see that https://gazebosim.org/api/sensors/8/thermalcameraigngazebo.html has the updated description, but https://gazebosim.org/api/sensors/9/thermalcameraigngazebo.html and https://gazebosim.org/api/sensors/6/thermalcameraigngazebo.html (which comes up for me when I google "gazebo thermal camera") still have the old one.

ported changes to ign-sensors6 and gz-sensors9