What is the purpose of the tangent constraint in Autodesk Inventor?

The tangent constraint in Autodesk Inventor is used to ensure that two curves, or a curve and a line, touch each other at exactly one point. This is particularly important in design, where precise relationships between geometric entities are required to achieve specific functional outcomes or aesthetic qualities. When a tangent constraint is applied, it maintains the smoothness between the two entities without creating any intersection or overlap, thereby preserving the integrity of the design.

For instance, in mechanical assembly or in creating freeform shapes, ensuring that curves connect at a single point allows for smoother transitions, reduces stress points in parts, and enhances the overall performance of the product. The ability to define this relationship accurately is crucial in CAD modeling to achieve the desired shapes and functionalities.

Aligning curves perfectly, creating parallel relationships, or allowing curves to overlap would not provide the necessary geometric control that a tangent connection offers, which is why those choices do not accurately describe the primary function of the tangent constraint.