Blend Curve Quick Help

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The Blend Curve tool will create a blended curve result between curves which are tangent to either the tangent field on the curve or to the curve itself. Note that the blend curve is not a Sketch or Shape object but a NURBS object with one visible edge. This enables us to maintain a tangent which would be the equivalent surface had a surface blend been made.

Usage:

1) Start Tool
2) Pick a start point on one edge/curve
3) Pick a ending point on a second edge/curve.
4) To make further adjustments to the curve go into Modifier mode.

NOTE: the Blend Curve is dependeng on the selected curves and will update if original curves are modified.

Pick Shapes/Edges:  Click on this button to begin picking curves / edges to blend
Auto Orient Tangents:  If this option is checked, it will automatically orient the tangency direction.
Tangent Strength:  Determines how strong the tangency of the resulting curve will be.  The larger the value, the more influence the tangency of the selected curve will have.
Flip Tangents:  Flip the direction of the tangency of both or just the selected tangent.

Optimized Blend:  The tolerance distance used to determine edge connectivity.   
B-Spline Blending:  Angle tolerance in degrees between two surfaces being made tangent.
Linear Segment:  The number of curves to use in defining the surface.

Specifies the blending continuity or smoothness of the curve blend.

G1 - Tangent Continuity:  G1 Tangent Continuity uses the first derivative of the adjacent faces to make the tangent direction continuous across the blend. It blends the first derivative direction between two surfaces.
G2 - Curvature Continuity:  G2 Tangent Continuity uses the second derivative of the adjacent faces so that the radius of curvature is continuous across the boundary between the adjacent surfaces and the blend. It blends 2 derivatives smoothly between two surfaces.
G3 - Deriv Continuity:  G3 Tangent Continuity uses the third derivative of the adjacent surfaces to make the rate of curvature change continuous across the boundaries of the surfaces and the blend surface. It basically blends 3 derivatives smoothly between the two surfaces.
 

Start Value: Position along the selected start curve where the blend starts. You may adjust the blend start position along the curve by spinning this value. Note that 0 and 100 are the corresponding start and end of the curve.

End Value: Position along the selected end curve where the blend ends. You may adjust the blend end position by spinning this value also.

Start - Tangent to Curve: Make the start point tangent to the selected curve instead of the tangent field of the curve.
End - Tangent to Curve: Make the end point tangent to the selected curve instead of the tangent field of the curve.