Custom Cross-Section Editor

Getting Started

1. In the Cross-Section card, click the Custom button.
2. Click Edit Shape to open the editor modal.
3. Modify the curve by dragging control points and handles.
4. Click Done to apply, or Cancel to discard changes.

Interactions

Move point

Click and drag a control point to reposition it.

Move handle

Click and drag a handle dot (green = outgoing, amber = incoming). In smooth mode, the opposite handle mirrors automatically.

Add point

Double-click on the canvas to insert a new point near the closest curve segment.

Delete point

Right-click a point to remove it (minimum 3 points). Also available via Delete/Backspace key.

Toggle smooth/sharp

Select a point, then use the smooth (curve) or sharp (corner) toggle buttons in the top-right of the canvas.

Keyboard Shortcuts

Arrow keys

Nudge the selected point. Hold Shift for fine adjustment.

Tab / Shift+Tab

Cycle through control points.

Delete / Backspace

Delete the selected point (if more than 3 remain).

Escape

Deselect the current point, or close the editor if nothing is selected.

Starter Presets

Use the Presets dropdown to load a starting shape:

Circle

4-point bezier circle approximation (default). Smooth handles produce a near-perfect circle.

Square

4 sharp-corner points forming a square. Add smooth mode to individual points for selective rounding.

Triangle

3 sharp-corner points forming an equilateral triangle.

Rounded Square

4 smooth points with short handles that produce gently rounded corners.

Star

10 sharp-corner points alternating between outer and inner radii. Adjust inner points to control the star depth.

Teardrop

4 smooth points forming an asymmetric teardrop shape.

Resolution

The resolution setting controls how many samples are taken along the bezier curve. Higher resolution produces smoother curves at the cost of more mesh vertices:

1x (Fast)

Base resolution. Good for simple shapes with few control points.

2x (Standard)

Double resolution. Default — suitable for most custom shapes.

3x (Detailed)

Triple resolution. Use for shapes with tight curves or many control points.

4x (Ultra)

Maximum resolution. For intricate shapes where every curve must be perfectly smooth.

The resolution multiplier is applied on top of the quality preset U segments. For example, at Standard quality (256 U segments) with 2x resolution, the circumferential resolution is 512 segments.

Corner Radius (Polygon Presets)

For the built-in polygon presets (Square, Triangle, Hexagon, Polygon), the Corner Radius slider applies true tangent-arc fillets to each corner:

• The radius is specified in millimeters and is relative to the object's maximum profile radius.
• At 0 mm, corners are perfectly sharp.
• As the radius increases, each corner is replaced by a smooth arc that remains tangent to both adjacent edges.
• Very large radii will cause adjacent fillets to merge, approaching a circular shape.

Corner Radius has no effect on Circle, Sine, and Custom presets — for Custom shapes, use smooth-mode control points to create rounded corners manually.

Sine Cross-Section

The Sine preset creates a flower-like or gear-like cross-section by applying sinusoidal radial deformation to a circle:

Lobes

Number of sine wave cycles around the circumference (1–20). Higher values create more petals or teeth.

Amplitude

Depth of the sine deformation as a multiplier. Values near 0 produce a near-circle. Values above 1 create overlapping folds.

Harmonics

Number of harmonic overtones added to the base sine wave (1–8). Higher values create richer, more complex profiles.

Pinch

Controls the asymmetry between valleys and peaks. Low values create narrow valleys with broad, flat peaks. High values do the reverse.

Koch Snowflake Cross-Section

The Koch preset generates a Koch snowflake fractal — a self-similar shape that starts as an equilateral triangle and recursively subdivides each edge into smaller triangular bumps.

1. In the Cross-Section card, click the Koch button.
2. Click Edit Koch Snowflake to open the editor modal with a live preview.
3. Adjust Iterations and Smoothing, then click Done.

Iterations

Fractal depth (0–5). At 0, the shape is a plain equilateral triangle. Each iteration subdivides every edge, adding triangular bumps. Vertex count grows as 3 × 4^n (3, 12, 48, 192, 768, 3072).

Smoothing

Rounds the fractal corners using Chaikin corner-cutting subdivision (0–1). At 0, the shape has sharp fractal corners. At 1, four rounds of smoothing produce a fully organic, rounded shape.

The circumferential resolution automatically scales with the iteration count to capture fine fractal detail.