I need opacity diminishing from the center of a thick spline orthogonally to the spline direction (tangent). I could come up only with piling up a few semi-opaque splines with decreasing width on the top of each other. Is there a simpler solution or just better alternative solution with a nice visual? Here is my code
Manipulate[
Graphics[{White, Opacity[g], CapForm["Round"], AbsoluteThickness[#],
BSplineCurve[pts]} & /@ Table[i^s, {i, 1, 10 s^2}],
PlotRange -> 1.3, Background -> Black]
, {{s, 1.3, "width"}, .5, 1.7}
, {{g, .15, "glow"}, .01, .5}
, {{pts, {{0.8, 0.8}, {-1, 0}, {0, -1}, {1, 0}, {-0.5, 0.5}}},
Locator, LocatorAutoCreate -> True,
Appearance -> Style["o", 40, Red]},
FrameMargins -> 0]
