Curviloft 18 [top] May 2026

Product Report: Curviloft 1.8 (SketchUp Extension)  Curviloft is a powerful surface modeling extension for SketchUp, developed by Fredo6, specifically designed for "Loft and Skinning". It allows users to generate complex organic surfaces from simple contour lines or frames. Version 1.8 (often referred to as Curviloft v1.8a) marked a significant point in the extension's development, transitioning from a free beta tool to a licensed product.  1. Key Tools and Features 

Curviloft consists of three primary tools that facilitate advanced organic modeling: 

Loft by Spline: Joins separate contours (open or closed) using smooth splines. It draws intermediate edges between your lines to create a face.

Loft Along Path: Similar to SketchUp's native "Follow Me" tool but more advanced. It allows you to loft a shape along a rail while transitioning between different shapes (e.g., a square becoming a circle).

Skin Contours: Creates a surface or "skin" bounded by 3 or 4 contiguous contours. This is widely used for creating tensile structures, roofs, or complex architectural exteriors.  2. Technical Requirements 

To run Curviloft successfully, the following dependencies must be installed on your system:  curviloft 18

LibFredo6: This is a shared library required for all Fredo6 plugins. Current versions typically require LibFredo6 v14.3b or above.

Sketchucation ExtensionStore: This is needed for license management and updates, specifically v4.4.0 or above.

Compatibility: Supports SketchUp versions from SU2017 to current, running on both Windows and Mac OSX.  3. Licensing and Pricing 

While earlier versions were free, Curviloft is now a paid extension licensed through Sketchucation. 

Free Trial: A 30-day full-feature trial period is available starting from the first usage. Product Report: Curviloft 1

Perpetual License: A one-time purchase of $15.00 covers a perpetual license for up to 3 seats.

Bundle Option: Users can also purchase the Fredo6Bundle (which includes 8 popular plugins like JointPushPull and RoundCorner) for $50.00.  4. Installation Steps  Register for a free account at SketchUcation. Install the Sketchucation ExtensionStore plugin. Install LibFredo6 (critical prerequisite).

Download the Curviloft RBZ file and install it via the SketchUp Extension Manager. Restart SketchUp to ensure all components load properly.  Curviloft

Curviloft is an essential extension for SketchUp, developed by Fredo6, that specializes in generating complex surfaces and organic shapes from contours. While "Curviloft 18" often refers to its compatibility with SketchUp 2018 or specific maintenance releases like version 1.8a, it remains a top-tier tool for architectural and organic modeling. Key Features & Tools

The extension is divided into three primary tools that handle different geometric challenges: Span: up to 18 m clear Standard radii: 1

Loft by Spline: Creates a smooth surface across a series of separate contours or frames. It automatically generates intermediate edges to "skin" the space between lines.

Loft Along Path: Functions similarly to SketchUp’s "Follow Me" tool but with significantly more control. It allows you to loft shapes along a rail, supporting multiple intermediate profiles to vary the shape (e.g., transition from a square to a circle).

Skinning (Skin Contours): Generates a mesh over a closed or open frame of edges. This is highly effective for creating tensile structures, terrain, or complex architectural skins. Ease of Use & Workflow

2. Fix "Ripples" on Flat Surfaces

If your loft creates wavy ripples where you wanted a flat panel, your input curves have uneven vertex counts. Use the "Rebuild Curve" feature (in CurviLoft’s right-click menu) to force all curves to have the same number of control points (e.g., 20 points each). This will create perfectly flat facets between curves.

Technical Specifications (Brief)

• Span: up to 18 m clear
• Standard radii: 1.5m / 3m / 4.5m / 6m / 9m
• Thickness: 18 mm (hence the name)
• Fire rating: Class A (ASTM E84)
• Moisture resistance: Impervious (suitable for pool areas and coastal climates)

3. Junction Mode (The "Holy Grail" Feature)

Perhaps the most powerful feature tucked into Curviloft is the Junction tool.

• The Problem: In native SketchUp, connecting three or more pipes (like a "Y" or "T" junction) with smooth curves is incredibly difficult and results in messy geometry.
• The Curviloft Solution: The Junction tool allows you to select three or more intersecting curves. The plugin then mathematically calculates the tangent continuity, generating a smooth, water-tight surface where the shapes meet. It effectively automates the complex "filleting" process of organic intersections.

1. Installation & Setup

• Install via SketchUp Extension Warehouse or Fredo6’s own installer.
• After install: Extensions → Curviloft → About & Settings to check language/units.
• Toolbar: Extensions → Curviloft or enable the Curviloft toolbar (View → Toolbars).

5. Limitations (in context of SU2018)

• No native undo stack integration – Undo sometimes required multiple steps.
• No live updating – If you changed input curves, you had to re‑run the tool.
• Performance – High‑poly lofts could freeze SketchUp 2018 temporarily.
• SketchUp 2018’s native tools – Unlike later versions (SU2021+ with native “Curve” tools), Curviloft remained essential for lofting.

2. Key Features (as of 2018 version)

• Loft along path – Create surfaces by extruding a profile along a curved path.
• Skinning – Generate a smooth surface between two or more cross‑section curves (edges or profiles).
• Contour generation – Create structural ribs or contour lines from a selected surface.
• Extrude edges by vector – Simple extrude along a straight direction (like native Push/Pull but for angled faces).
• Mesh/quad face output – Option to output triangles or quads for further manipulation.

Key Features of CurviLoft 18

If you are searching for a detailed breakdown of what CurviLoft 18 offers, these are the headline features that set it apart from standard modeling tools: