X-Plane 11.0 shipped with all new Physically Based Rendering – the lighting and material model is based on the real physics of light interacting with dielectrics and metals (kind of) to make rendering look more realistic with less art tuning.
But…X-Plane’s night lighting in X-Plane 11.00 is not physically correct – the night lights ignore the materials and do what X-Plane 10 did.
X-Plane 11.01 betas fix this. In the pictures below you can see side-by-side comparisons of the same scene with the 11.00 lighting and the new physical night lighting for 11.01. The array of balls floating around the Cessna is a test project I use with a 2-d grid of materials (metal on the bottom, rough on the right).
One of the effects of this is increased accuracy of light location – that is, you can really tell where the lights are by the reflections they cast on specific materials.
Here are some material comparisons with the day seen included so you can see what the original materials were. Observe the rim of the engine cowlings on the 737 and 747, and of coarse the entire fuselage on the MD-82.
There’s no authoring change needed or work to do for third parties – if you were modeling your aircraft to look correct during the day, 11.01 makes the night lighting look better.