Improving simulation rendering realism

[luca-della-vedova]

Feature request

Description

It would be great to start using high resolution textures as well as more modern rendering workflows supported by Ignition (i.e. PBR or Physics Based Rendering) to increase realism.
Apart from the ✨ effect it's also important for people who would want a more realistic simulation environment for example for testing computer vision / localization algorithms in their robots together with RMF.

Implementation considerations

A current indoor environment (office) without advanced lighting and textures looks like this:

While a scenario with lightmaps, high resolution textures, environment / roughness / normal maps looks like this:

There is multiple steps to achieve such quality of rendering, all of them except n.1 are only applicable to Ignition since Gazebo classic doesn't support most modern rendering features:

• High resolution diffuse texture support Added support for fuel textures #342
• Add support for texture scaling in walls added scaling features to wall texture #382
• PBR textures support, (normal, roughness, metal maps) PBR textures for walls and floors in Ignition Gazebo #345
• Environment map generation and upload to fuel, reference the ign-rendering tutorial
• Adding ceilings with textures for lights added support for ceilings with texture #383
• Baking lightmaps and applying to the whole environment, tutorial

All of this should be done in a backward compatible way to avoid breaking behavior in Gazebo classic.