Can I make a bevel curve transition to another one during the same bevel process? My situation is as follows:
I want to create a curved plane that has a crease or ditch at one end and is flat at the other.
To achieve this, I created a curve (curve 0) that defines my plane, then used another U-shaped curve (curve 1) to bevel the first one, creating the actual plane with the ditch or crease (the U shape of the crease or ditch being defined by curve 1).

Now my question is: can I create a third curve (curve 2) that is just a straight line and have the bevel transition from curve 1 to curve 2 over the distance of curve 0?
I don't know of a way to to morph a bevel from one curve to another.  If you want a blend a curved plane from one profile to another you need a NURBS surface.




Add (Shift + A) a Surface, NURBS Curve.
Edit the curve to the profile you want for one end of the surface.
Duplicate (Shift + D) the curve and move it along the Y-axis.
Flatten out the curve control point by scaling them in the Z-axis.
Select both curves and press F to loft them into a surface.