Trajpar (trajectory parameter) is a variable section sweep technique used in Creo/Pro-ENGINEER to create geometry that changes shape smoothly along a path — tapering, blending, or transitioning a cross-section as it travels from one end of a feature to another. It's the modeling approach behind complex, organic, or continuously-varying shapes that a standard extrude, revolve, or fixed-section sweep simply can't produce.

We use Trajpar-driven variable section sweeps for parts where the cross-section needs to change predictably along its length — handle grips that taper and twist, ducting that transitions between different profile shapes, blended transitions between two different feature geometries, and other forms where a smooth, mathematically controlled shape change is the design requirement itself.

Ergonomic product shapes — grips, handles, and housings that taper or curve to fit the hand or body

Ducting and flow-path components transitioning between different cross-sectional shapes

Blended transitions between two dissimilar features on the same part

Complex surfacing work where a relationship-driven, parametric shape change is more reliable than manual surface manipulation

Relation-driven variable section sweep geometry built in Creo/Pro-ENGINEER

Parametric control, so the shape updates correctly if trajectory or reference dimensions change

Smooth, manufacturable surface quality suited for downstream machining, molding, or 3D printing

Export to your required CAD format for further use or manufacturing

Product designers with complex, continuously-varying shapes that standard sweep/loft tools can't handle cleanly

Engineers working in Creo/Pro-ENGINEER who need advanced parametric surfacing support

Teams needing a shape redesigned to be fully parametric rather than a one-off manual surface