Loft to mesh¶
A loft builds a surface that runs through a sequence of input curves. The Designer's loft is the fastest way to author smooth 3D geometry from 2D curves.
Setup¶
- Author two or more cross-section curves. They can be Bezier or NURBS, open or closed, and do not need the same vertex count.
- Position them along the loft axis (typically the z-axis).
- Select them all (Shift-click) in the order you want the loft to traverse.
Surfaces > Loft to Mesh.
The Designer creates a new Mesh3D placement and hides (but does not delete) the input curves.
Options dialog¶
The Loft to Mesh action opens a small dialog:
| Option | Default | Notes |
|---|---|---|
| Sections | input count | How many curves to interpolate between |
| Smoothness | 24 | Subdivisions across each section |
| Across | linear | linear / bezier / nurbs interpolation between curves |
| Caps | open | open / close-at-ends / close-both |
| UV mapping | cylindrical | cylindrical / planar / preserved |
The defaults produce a smooth surface with reasonable topology.
Cross-curve resampling¶
Loft requires curves with matched parametrization. The Designer auto-resamples each input curve to a common vertex count. To control this:
- Resample: on by default. Picks the highest vertex count of any input curve and resamples the others to match.
- Reverse direction: per-curve toggle if a section comes out flipped (look for inside-out shading; flip the offending curve).
- Align: re-align the curves' first CVs so they line up along the loft direction; toggles off when you want a twist.
Closed vs open lofts¶
- Inputs all open → open loft (a strip).
- Inputs all closed → closed loft (a tube).
- Inputs mixed → undefined; the Designer warns and treats them as open.
For a Möbius strip, set Reverse direction on every other curve.
After lofting¶
The resulting Mesh3D placement has standard transform / mask / material properties. To re-author:
- Right-click the Mesh3D placement > Show Source Curves.
- Edit the curves.
- The loft auto-re-runs and updates the mesh in real time.
The link between curves and mesh is non-destructive; the curves remain editable so long as the Mesh3D placement is in the project.
UV mapping¶
The Designer offers three UV strategies:
- Cylindrical: U follows the cross-curve direction, V follows the along-curve direction. Best for tube-like lofts.
- Planar: U / V are world-space x / z of the input curves. Best when you want textures to "lay flat" across the surface.
- Preserved: keeps each input curve's U coordinate and interpolates V from input index. Best when the cross-sections carry meaningful texture coordinates already (rare).
Performance¶
A 24-section x 24-smoothness loft creates ~576 quads (~1152 triangles). The Designer handles up to ~10,000-quad lofts in real time; beyond that, prefer authoring topology in a DCC and importing.
Limitations¶
- Loft is one-directional only (along a single sweep). For bidirectional surfaces (think of a checkerboard of curves), loft pairs separately and combine via the boolean tools.
- No spline-sweep "rail" mode in v1; the loft moves linearly / smoothly between sections.
See also¶
- Curves index: author the input curves first.
- NURBS: predictable cross-sections for analytic lofts.
- Importing 3D models: when to loft vs DCC and import.