How do I use Two Rail Sweep + Clear Outside together to create organic leaf, scroll, and organic relief shapes in Aspire?

Overview

The Two Rail Sweep plus Clear Outside (cookie cutter) technique is one of Aspire's most useful organic modeling workflows. Two Rail Sweep makes a shape that follows the rail path well, but the component can extend beyond the outline you want. Clear Outside then trims the component to the intended vector shape, combining the profile control of Two Rail Sweep with the precise silhouette of a vector outline. For the full list of Clear and Split options, see the entry on Clear and Split Components. For setting up the sweep itself, see the entry on how Two Rail Sweep works.

This is the standard technique for:

• Organic leaf shapes with a specific edge profile
• Carved scrolls and flourishes
• Feathers and wings
• Fish and organic body shapes
• Ribbons and banners with specific edge shapes

The Classic Leaf Workflow (official documentation example)

The official documentation demonstrates this technique with a leaf.

Why This Works Better Than Single-Step Approaches

Create Shape alone: can make a dome over the leaf outline, but the profile radiates evenly from the center and does not give directional flow along the leaf's length.

Two Rail Sweep alone: gives directional flow along the leaf's spine, but the shape extends to the rail boundaries and not to the actual leaf edge.

Two Rail Sweep plus Clear Outside: gives both the directional profile and the precise silhouette.

Generalized Application

Use the workflow whenever you want a 3D profile that flows in a certain direction (along a spine, vein or structural axis) but the silhouette must match a precise outline.

Scrolls and flourishes: draw two rails along the scroll's spiral path, sweep a round or tapered cross-section, then Clear Outside with the scroll's outline vector.

Feathers: rails are the feather shaft and the outer edge curve, the cross-section is thin near the edges and fuller in the center, then Clear Outside with the feather outline.

Fish body: rails are the top and bottom of the body profile, the cross-section is the dome shape of the body, then Clear Outside with the fish silhouette.

Variation: Two-Stage Cookie Cutting

For shapes with inner cutouts:

1. Two Rail Sweep to create the base component
2. Clear Outside with the outer boundary vector
3. Draw the inner cutout vector (for example a hole)
4. Select the swept component, then the inner vector
5. Clear Inside to remove the material in the cutout

Selection Order is Critical

1. Select the 3D COMPONENT first (the thing you want to modify)
2. Select the VECTOR last
3. Click Clear Inside or Clear Outside

The last selected object defines the cropping region, and the first selected object is what gets cropped. If the order is wrong, the wrong object becomes the boundary.

Common Mistakes

• Selecting the vector first and the component last
• Using Clear Inside when Clear Outside is needed, or the reverse
• Not keeping a backup copy first, because the clear changes the component permanently (Ctrl+Z only works straight away)
• Using a boundary vector that does not line up with the model's visual edge, which leaves a visible step or gap at the trim edge
• Not smoothing the boundary vector first, since a jagged vector gives a jagged component edge