Master Organic Shapes: A Guide to the Curviloft Plugin for SketchUp
If you’ve ever tried to model a complex, swooping roof or a piece of ergonomic furniture in SketchUp using only native tools, you know the struggle. While the
tool is great for basic extrusions, it often falls short when you need to transition between two different shapes or "skin" a complex wireframe. , a legendary extension by
that turns SketchUp into an organic modeling powerhouse. Here is everything you need to know to get started. What is Curviloft? Curviloft is a script dedicated to Loft and Skinning
—generating surfaces from contours. It’s part of the Fredo6 collection and is essential for anyone doing architectural or organic design. Key Features
Curviloft provides three primary tools that handle different geometric challenges: Loft by Spline:
Connects two or more separate profiles. For example, you can seamlessly bridge a square base to a circular top. Loft Along Path:
Extrudes a profile along a specific guiding line or "rail," allowing for precise control over curved forms.
Creates a surface (or "skin") over a frame of three or four bordering contours. This is perfect for filling in complex wireframe structures. How to Install
Because Curviloft is a Fredo6 plugin, it has specific dependencies you must install first:
Curviloft is a specialized SketchUp extension developed by Fredo6 that simplifies the creation of organic, non-linear geometry by generating surfaces from existing curves or contours. It is widely considered an essential tool for architects and 3D modelers who need to create complex "skins" or smooth transitions between different shapes. Core Functionality
The plugin is divided into three primary modeling modes, each tailored for different geometric challenges:
Loft by Spline: Connects separate contours (like a circle and a hexagon) with smooth, interpolated splines to create a continuous surface.
Loft Along Path: Generates a surface by following a specific "rail" or path defined by the user. It offers methods like Stretch, Offset, and Sweep to control the resulting shape's thickness and deformation.
Skinning: Creates a "skin" over a frame of four or more intersecting or adjacent edges, ideal for filling complex organic gaps. Key Features & Workflow
Interactive Preview Mode: After selecting your curves, the tool enters a preview state where you can adjust parameters and see the changes reflected in real-time before finalizing the geometry.
Pseudo-Quads Generation: Curviloft can generate "pseudo-quad" meshes, which are compatible with other advanced tools like QuadFaceTools for further mesh refinement.
Vertex Matching: It automatically attempts to line up vertices between contours of different segment counts, though users can manually add "separators" to control exactly where the mesh splits. Requirements & Installation
To use Curviloft, you must install several components through the SketchUcation ExtensionStore:
LibFredo6: The foundational shared library required for all Fredo6 plugins (v14.3b or above). curviloft plugin sketchup
SketchUcation ExtensionStore: Necessary for managing the plugin and its license.
Restart: You must restart SketchUp after installation for the tools to load properly. Licensing Information
As of recent updates, Curviloft is a paid/licensed extension:
Free Trial: A 30-day full-feature trial period is available from the first usage. Perpetual License: Approximately $15 for a 3-seat license.
Bundle Option: It is included in the Fredo6Bundle (containing 8 plugins) for approximately $50.
For those looking for free alternatives, while less powerful, users often look toward tools like Simple Loft by Chris Fullmer or the native Extrude Tools by TIG.
Other plugins similar to Curviloft, RoundCorner and JointPushPull
Curviloft is a powerful organic modeling extension for SketchUp developed by Fredo6. It is essential for creating smooth, complex surfaces from contours or curves—a task that is otherwise difficult to perform manually in native SketchUp. Core Functions Curviloft operates through three primary tools:
Loft by Spline: Joins separate, non-intersecting contours (open or closed) by generating smooth splines between them. For example, it can merge a hexagon and a circle into a single organic form.
Loft Along Path: Follows a designated "rail" curve to join contours, effectively sweeping a shape along a custom trajectory.
Skinning: Creates a surface or "skin" bounded by three or four contiguous contours, filling the frame with new geometry. Why It’s Useful
A plugin similar to Curviloft but different function/features - SketchUp
Curviloft: Mastering Organic Geometry in SketchUp SketchUp is renowned for its simplicity, yet its native tools often struggle with the complex, non-linear forms required for modern architecture and product design. Enter Curviloft, a transformative extension developed by Fredo6. Dedicated to "lofting" and "skinning," Curviloft allows users to bridge the gap between simple line work and sophisticated, organic surfaces. Core Functionalities
Curviloft simplifies organic modeling through three primary generation modes:
Loft by Spline: This mode connects separate contours or faces using smooth splines. It is ideal for creating flowing, continuous shapes where each segment transitions naturally into the next.
Loft along Path: This tool generates a surface by following a specific user-defined rail or curve. It offers multiple generation methods—such as Stretch, Offset, and Sweep—to ensure the resulting geometry maintains the correct thickness and orientation.
Skinning: Perhaps the most powerful feature, skinning creates a surface over a frame or set of bordering contours. By selecting 3 or 4 contours, users can "patch" empty spaces with complex, curved geometry, effectively building "skins" over skeletal structures. Installation and Integration
is a specialized extension for SketchUp, developed by , that enables the generation of complex, organic surfaces from contour lines and frames. It is considered an essential tool for architects and designers who need to model geometry that the native SketchUp toolset, like the Follow Me tool , cannot easily handle. The SketchUp Essentials Core Functionality & Tools
Curviloft consists of three primary modes, each designed for specific geometric challenges: Loft by Spline Master Organic Shapes: A Guide to the Curviloft
: Joins separate open or closed contours using smooth spline curves to create a continuous surface. This is ideal for creating complex, tapering shapes like vase forms or aerodynamic bodies. Loft along Path
: Similar to the native "Follow Me" tool but much more advanced; it allows you to extrude one or more profiles along a dedicated path while maintaining smooth transitions between different profile shapes.
: Fills in the gaps between a set of intersecting or bordering edges (a wireframe) to create a solid "skin" or mesh. This is frequently used for terrain modeling or organic roof structures. The SketchUp Essentials Key Technical Features Dynamic Preview
: Users can adjust parameters like the number of segments and interpolation methods in real-time before finalizing the geometry. Vertex Matching
: The plugin automatically attempts to align vertices between different contours to ensure the resulting mesh is clean and symmetrical. Geometry Generation
: It can produce both finalized faces (skins) and the underlying contour lines for further manual editing. The SketchUp Essentials Installation and Requirements Curviloft is distributed as an and requires a specific installation process: SketchUcation LibFredo6 Requirement : You must first install the LibFredo6 shared library , as Curviloft relies on it to function. Download Source : The plugin is primarily available through the SketchUcation Plugin Store Installation Extension Manager in SketchUp ( Window > Extension Manager ) to install the downloaded RBZ files.
: While previously free, many of Fredo6's plugins, including Curviloft, now operate under a paid license model (standard for SketchUcation's premium extensions). SketchUcation Common Use Cases Architecture
: Designing curved ramps, organic facades, and complex rooflines. Furniture Design
: Modeling ergonomic chairs, handles, or decorative carvings that require smooth, non-linear transitions. Terrain Modeling
Report: Curviloft Plugin for SketchUp
Date: October 26, 2023 Subject: Technical Review and Application Analysis of Curviloft Prepared For: SketchUp Users and 3D Modeling Professionals
This is the most intuitive tool. You provide a Path (a single line, curve, or polyline) and a series of Profiles (shapes perpendicular to the path).
Select a series of edges or curves that form a closed or open network. Curviloft generates a skin across them.
This tool takes a solid mesh or a set of edges and generates evenly spaced horizontal lines across it. Alternatively, you can select a set of horizontal lines, and Curviloft will construct a terrain surface.
How to use it:
Best for: Landscape architecture, site models, terrain from CAD files, and 3D printing organic landmasses.
In the world of 3D modeling, few tasks are as notoriously difficult as organic surface creation. For years, SketchUp users struggled with a frustrating reality: while the software excelled at hard-edge architecture (boxes, walls, roofs), creating a smooth car body, a flowing fabric canopy, or a terrain transition felt nearly impossible. Then came Fredo6’s Curviloft Plugin for SketchUp.
Curviloft isn't just another extension; it is a paradigm shift. It brings the power of lofting, skinning, and contouring—features native to high-end engineering software like Rhino or SolidWorks—directly into SketchUp’s intuitive interface. If you design furniture, architecture, product prototypes, or landscapes, mastering Curviloft is the single fastest way to elevate your modeling portfolio from "amateur" to "professional."
This article will serve as your complete encyclopedia for Curviloft. We will cover what it is, why you need it, the core algorithms (Loft, Skin, and Contour), a step-by-step workflow, troubleshooting common errors, and advanced tips for power users. Tool 1: Loft by Spline (The "Path" Loft)
❌ Requires LibFredo6 – Not a true standalone plugin; you must install another framework. (Minor issue – installation is straightforward).
❌ No real NURBS – Curviloft outputs triangles and quads (polygons), not mathematical surfaces. For precise CAD work (e.g., CNC with tight tolerances), you may need to export as STEP via other workflows.
❌ Complex network lofts can be tricky – The order of curve selection matters; beginners sometimes get “gutted” or twisted results.
❌ Older UI – It has not seen a modern redesign; it looks like a plugin from 2015.
❌ No dynamic updating – If you move an original curve, the loft does not auto‑update. You must re‑run the tool.
Summary: Curviloft turns SketchUp into a surface-modeling powerhouse. Master the three core tools (Loft by Spline, Loft along Path, Skinning) and you can create anything from organic furniture to architectural shells.
Would you like a specific example (e.g., making a spiral staircase surface or a terrain mesh)?
is an essential organic modeling extension for developed by Fredo6. It bridges the gap between SketchUp's native tools and complex surface modeling by generating skins and lofts from contours. As of early 2026, it remains a "must-have" for architects and designers dealing with non-planar faces and flowy geometry. Core Functionality
The plugin provides three primary methods for creating geometry: Loft by Spline
: Joins separate contours or profiles using smooth splines to create a continuous curved surface. Loft Along Path
: Generates a surface by sweeping one or two profiles along a user-defined curve or rail.
: Creates a face or "skin" by connecting three or four bordering contours, perfect for complex roofs or tensile structures. Pros & Cons Curviloft for Sketchup – 2 minute Tutorial Curviloft for Sketchup – 2 minute Tutorial Sketchup Style Using Curviloft #sketchup
Curviloft is a powerful, free extension for SketchUp developed by Fredo6 that allows you to create complex curved surfaces (skins) from lines and contours. It is an essential tool for organic modeling, as it automates the creation of geometry that would be nearly impossible to draw manually. 1. Getting Started
To use Curviloft, you must install two components from the Sketchucation Extension Store: Curviloft Plugin: The main tool.
LibFredo6: A shared library required for all Fredo6 plugins to function. 2. The Three Primary Tools
Curviloft consists of three main modes, each accessible from its toolbar:
Loft by Spline: Creates a surface (skin) by connecting two or more separate contours or profiles. It "lofts" the space between them.
Loft along Path: Similar to SketchUp's native "Follow Me" tool, but much more advanced. It allows you to sweep a profile along a path while varying the scale or rotation of that profile along the way.
Skinning: Generates a surface over a closed wireframe of four or more edges. This is ideal for filling in gaps in complex organic shapes. 3. Basic Workflow
Select Your Lines: Use the Select tool to highlight the edges or contours you want to use. Activate Curviloft: Click one of the three Curviloft icons.
Preview & Adjust: A floating interface will appear. You can adjust settings like "Segment Number" to make the curve smoother or "Interpolation" to change how the surface flows between lines.
Finalize: Click outside the geometry or press Enter to generate the final surface. 4. Pro Tips for Better Results
Smooth Your Geometry: After creating a surface, use the Soften Edges tray (Window > Default Tray > Soften Edges) to hide the mesh lines and make the surface look seamless.
Check Line Continuity: Curviloft works best when your contours are clean. If a surface fails to generate, check for tiny gaps in your lines.
Inference Locking: Use the arrow keys while drawing your initial profiles to lock them to the Red, Green, or Blue axes, ensuring your organic shapes stay aligned correctly. Curviloft for SketchUp Tutorials