PlotPoints does NOT work

[mxue]

It seems that setting different values in PlotPoints makes no difference. For example,

Plot3D[Sin[x]*Sin[y], {x, -6,6}, {y, -6,6}, PlotPoints->15]

looks the same as

Plot3D[Sin[x]*Sin[y], {x, -6,6}, {y, -6,6}, PlotPoints->60]

Thanks in advanced for any help from fellow Mathematica users

-M

[Gerd]

PlotPoints does work, you just do not see it in your example beacuse 15 and 60 are both high numbers. Draw it with 2 or 3 or 4 and you will see the difference.

[szhorvat]

It does work, but PlotPoints doesn't exactly do what you think. It sets the initial number of points. Mathematica may automatically add additional points adaptively for a better quality plot.

MaxRecursion controls the number of refinement steps when adding points.

To see all the plot points, use the Mesh -> All option. You will notice that with PlotPoints -> 15 the mesh is not regular. Mathematica used a fine mesh around the maxima where the curvature is high, but it didn't do any refinement elsewhere. PlotPoint -> 60 causes the mesh to be fine everywhere.