About this Block
What it does: The Conic Section Sweep by Tangent block creates an implicit body by sweeping a conic section along a spine curve between two rail curves (Rail 1 and Rail 2). Unlike the standard conic sweep, this block allows you to control the surface shape using tangent vector fields at each rail, in addition to a spatially varying Rho field.
Common uses:
- Designing aerodynamic profiles for wings, fuselages, and other vehicle bodies.
- Modeling smooth transitions in components like ducts, inlets, and nozzles to manage fluid flow.
- Creating architectural features like arches and curved facades.
- Use this block when you need precise control over the surface tangency to match adjacent geometry or strictly define the “take-off” angle of the surface from the rails.
- This block offers more advanced control than the standard Conic Section Sweep block by allowing you to define the angle at which the surface leaves the rails using Vector Fields.
- It is recommended to avoid steep angles between the rail curves and the spine to avoid unexpected shelling and offset results downstream. A threshold of 45-60 degrees is a good rule of thumb.
- We recommend using the Boolean Intersect block to create closed surfaces from the output of this sweep.
- You can change the Rho value via a Ramp block to vary the conic shape spatially along the sweep.
- If you encounter errors while using this block, please check the following conditions:
- Closed Rail Curves: Rail 1 and Rail 2 cannot be closed curves. If you receive an error regarding closed rails, please replace them with open curves.
- Curve Intersections: An error regarding “improperly configured inputs” often indicates that the geometry is self-intersecting relative to the axis. Please ensure that rays projected from the axis along the specified direction intersect the curve only once.
Example File
Download Example: Lofting by Section SweepCreates an implicit body by sweeping a conic section along a spine curve between two rail curves, where the conic shape is controlled by spatially-varying Rho fields and tangent vector fields. The Rho parameter defines the conic shape factor at each point along the sweep (0.5 for parabolic, <0.5 for elliptical, >0.5 for hyperbolic sections), allowing smooth transitions between different conic types.
Inputs
| Name | Type | Description |
|---|---|---|
| Rail 1 | Curve | The first boundary curve that guides and constrains one side of the swept conic section as it travels along the spine. |
| Rail 2 | Curve | The second boundary curve that guides and constrains the opposite side of the swept conic section as it travels along the spine. |
| Spine | Line | A line that defines the sweep path and orientation for the conic section as it moves between the two rail curves. |
| Tangent 1 | Vector Field | A vector field that specifies the direction of the Conic tangent handle at rail 1 for each point along the spine. |
| Tangent 2 | Vector Field | A vector field that specifies the direction of the Conic tangent handle at rail 2 for each point along the spine. |
| Rho | Scalar Field | A scalar field (0 to 1) that controls the conic shape factor at each point, where 0.5 produces a parabola, values less than 0.5 create elliptical sections, and values greater than 0.5 create hyperbolic sections. |
Outputs
| Type |
|---|
| Implicit Body |