Bug introduced in 11.2 or earlier and persisting through 13.0
There are something wrong when I try to evaluate the example from Lighting
Docs, here is the code:
lights = {{"Spot", Red, {{3, 3, 5}, {3, 3, 0}}, Pi/8}, {"Spot", Green, {{7, 3, 5}, {7, 3, 0}}, Pi/8}, {"Spot", Blue, {{5, 6, 5}, {5, 6, 0}}, Pi/8}};
plane = ParametricPlot3D[{u, v, -2}, {u, 0, 10}, {v, 0, 9}, PlotPoints -> 100, MaxRecursion -> 0, Mesh -> None, Axes -> False];
Show[plane, Lighting -> lights]
Unfortunately, it does not work as expected in Mathematica version 11.3:
But if we directly use the form
ParametricPlot3D[{u, v, -2}, {u, 0, 10}, {v, 0, 9}, PlotPoints -> 100, MaxRecursion -> 0, Mesh -> None, Axes -> False,Lighting -> lights]
it works:
So I want to know the reason for creating the different outcomes, maybe researching the InputForm
of output seems a feasible point, but I failed. Thanks for any info on this matter.