About Second Constraints Definition for Curves
When the primary constraint on a curve tangent is G1 - Surface Tangent, G2 - Surface Curvature, G3 - Surface Acceleration, or Draft Tangent, the tangent is projected on the tangent plane. You can further constrain its placement by defining the second tangent constraint.
The following secondary constraints are available:
• Natural
• Free
• Angle
• Horizontal
• Vertical
• Normal
• Align
• Normal to Edge/Curve—When primary constraint is G1 - Surface Tangent, G2 - Surface Curvature, or G3 - Surface Acceleration
• Along U—When primary constraint is G1 - Surface Tangent, G2 - Surface Curvature, or G3 - Surface Acceleration
• Along V—When primary constraint is G1 - Surface Tangent, G2 - Surface Curvature, or G3 - Surface Acceleration