Is this continuous enough:?
Capture3.JPG
If so, change the data series to show without markers, and with a solid line instead, then tweak one or two lines in your macro to become:
End If
'apply color to point
'pt.Format.Fill.ForeColor.RGB = myColor
pt.Format.Line.ForeColor.RGB = myColor
'set a default marker size
'pt.MarkerSize = 3
Next
(you don't need the lines beginning with an apostrophe)
This might be good enough for you. If so, no need to reduce the number of points plotted but be aware that the chart is now telling fibs; originally it was showing the terrain AT the point plotted only, now it's showing the terrain for the point by colouring the line BETWEEN points as if the terrain along the whole length of the line betewen two points is that terrain, when it might not be the case. If the points are always quite close together, it may not matter.