Hi,
Sorry I have no idea. Have you tried separating the front/back shapes?
Instead of using taper (which is a local scaling) you can use blending between shapes, where
you have much more control over the shapes (tapering is a special case!).
Look my scene. The next step can be adding more blend shapes (with ramps), there are only 2 at the moment controled by one ramp. If you want 3 shapes you need 2 ramps an so on.

@Aizatulin that is the shape for which I'm after, except. What do you mean tapering is a special case ? How can I taper along the X ?

Hi,
if you construct your geometry by shapes extruded along a path (which is the case here), you can achieve tapering by blending between two shapes, where the first is the original one and the second is a scaled duplicate, because corresponding scaled points are always on one direct line, for example you cannot imitate twisting with blending (except for small angles), because twisting is local rotation, where rotated points lie on an arc. Note that the “normal” blending interpolates two points directly on a straight line and if you blend between two shapes, then every corresponding point pair will do so. If the second shape is a scaled duplicate, then the blending performs like scaling.
But you can achieve many other results by blending , so scaling (which is tapering along path here) is just a special case for blending, if you construct your geometry by extruding a shape along a path, but of course you can taper the extruded geometry aswell if you want, do you have tried the to apply the taper-operator from the “taper_curve_simple” for example?

Sorry taper_curve_simple ?

Hi,
it was related to the filename I've posted before, but you can do it already in the latest file.

Aizatulin
Hi,
are always on one direct line, for example you cannot imitate twisting with blending (except for small angles), because twisting is local rotation, where rotated points lie on an arc. Note that the “normal” blending interpolates two points directly on a straight line and if you blend between two shapes, then every corresponding point pair will do so. If the second shape is a scaled duplicate, then the blending performs like scaling.

I don't understand what you meant ?

But you can achieve many other results by blending , so scaling (which is tapering along path here) is just a special case for blending, if you construct your geometry by extruding a shape along a path, but of course you can taper the extruded geometry aswell if you want, do you have tried the to apply the taper-operator from the “taper_curve_simple” for example?

taper_curve_simple is a scene file ?

When I said taper along X I meant; not tapering the whole arc as some of parameters in your example scene. Similar to applying a soft selection to loops of primitives and taping those along the X for example if you wanted to taper a tear drop although not precisely in the example scenes you've posted ?