How to Design and 3D Print a Voronoi Coaster in Autodesk Fusion
Updated September 19, 2026
A Voronoi pattern can turn a simple coaster into an eye-catching 3D print, but converting an AI-generated image into printable geometry requires a few important steps. In this tutorial, you’ll use ChatGPT, Inkscape, Autodesk Fusion (formerly Fusion 360), and PrusaSlicer to create a coaster with a detailed cellular pattern and dimensions suitable for FDM printing.
What You’ll Learn
- How to generate a clean, printable Voronoi pattern with ChatGPT
- How to convert a raster image into an SVG using Inkscape
- How to import and scale an SVG in Autodesk Fusion
- How to turn the pattern into a 3 mm-thick 3D model
- How to strengthen the coaster’s outer rim
- How to add a subtle 0.25 mm chamfer
- How to preview color combinations before printing
- How to export the design as an STL and prepare it in PrusaSlicer
Watch the Workflow — or Read It Step by Step
You can follow this guide in two ways:
- Read the steps below if you want quick written instructions, reference images, and modeling notes.
- Watch the full video at the end of this post to see the workflow in real time — including extra tips, camera angles, and shortcuts that don’t fit neatly into text.
Both formats build on each other.
Reading helps you understand why each step matters, while watching shows how to move faster in Fusion.
Step 1: Generate a Voronoi Pattern With ChatGPT
Start by asking ChatGPT to generate a Voronoi pattern inside a circle. Make it clear that the pattern will be used for 3D printing so that the design does not contain excessively thin walls.
Thin sections may look good in a digital image but can become fragile, print inconsistently, or disappear entirely when converted into toolpaths. The minimum printable wall thickness depends on your nozzle diameter and slicer settings, so inspect the pattern before committing to the final model.
The first generated image may contain shadows and color gradients. These effects add visual depth, but they also make the image more difficult to trace accurately in vector software.
The initial prompt asks ChatGPT to create a circular Voronoi pattern for 3D printing. Two physical constraints are included from the start: a target diameter of 100 mm and walls no thinner than 1.2 mm.
Specifying printable dimensions during image generation helps steer the pattern toward wider cellular boundaries. The rendered shadows and gradients make the result visually convincing, but they produce ambiguous edges when the image is converted into vector geometry.
Ask ChatGPT to generate a clean black-and-white version with:
- Clearly defined black edges
- A white background
- No shadows
- No gradients
- Walls thick enough for 3D printing
A high-contrast image gives Inkscape cleaner boundaries to detect in the next step.
The Voronoi pattern has been regenerated as a high-contrast black-and-white graphic. Removing the shadows and tonal gradients creates clearer boundaries between the solid walls and open cells.
This simplified version is better suited to bitmap tracing in Inkscape. A clean source reduces unnecessary vector nodes and makes it easier to produce closed profiles that can later be extruded in Fusion.
Step 2: Import the Image Into Inkscape
Open Inkscape and drag the AI-generated image directly into the workspace.
You can also import it by selecting:
File > Import
Inkscape is a free vector graphics program. In this workflow, it acts as the bridge between the raster image generated by ChatGPT and the SVG geometry needed in Fusion.
The generated PNG is imported into Inkscape with Embed selected. Embedding stores the bitmap inside the Inkscape document instead of linking to an external file.
The default image resolution is retained, and Smooth (optimizeQuality) is selected as the rendering mode. These settings affect how the bitmap is displayed in Inkscape, while the following tracing operation determines the actual vector geometry.
Step 3: Trace the Voronoi Pattern
Select the imported image and open:
Path > Trace Bitmap
With the imported pattern selected, Path > Trace Bitmap is opened in Inkscape. The panel initially displays Brightness cutoff, which separates pixels according to a threshold value.
Brightness Cutoff can work with simple silhouettes, but this project needs the boundaries of the Voronoi walls rather than a filled interpretation of the entire graphic. The detection method is therefore changed in the next step.
The tracing controls will appear on the right side of the workspace. Under Detection Mode, change the setting from Brightness Cutoff to Edge Detection.
Edge Detection is well suited to this image because the source consists of sharp black lines against a white background. The cleaner the original image is, the easier it becomes for Inkscape to identify the Voronoi cell boundaries.
Review the preview and click Apply to generate the traced vector geometry.
The traced result is created on top of the original image. Move it temporarily to confirm that the trace was successful, then delete the original raster image.
Save the remaining vector pattern as an SVG file.
The Trace Bitmap detection mode is changed to Edge detection, with the visible edge threshold set to 0.650. The preview displays the detected outlines before the trace is applied.
Edge Detection follows the transitions between the black walls and white cells. For this workflow, that produces vector paths that more closely match the boundaries needed to form printable profiles in Fusion.
Step 4: Import the SVG Into Autodesk Fusion
Open Autodesk Fusion and create a new design.
Start a sketch on a horizontal construction plane. Choosing a horizontal plane makes the design orientation correspond with the way the coaster will sit on the 3D printer’s build plate.
Import the vector pattern using:
Insert > Insert SVG
The workflow moves into Fusion, where Insert > Insert SVG is selected. This command imports vector artwork into an active sketch and converts the SVG paths into editable sketch geometry.
SVG is preferable to importing the pattern as a canvas because the traced boundaries can be selected as profiles and used directly by solid-modeling commands such as Extrude.
Locate the SVG file on your computer and place it inside the sketch. Fusion may rotate the view while inserting the SVG, so reorient the camera if necessary.
Fusion’s Insert dialog is open with the Insert from my computer option available. The exported Voronoi SVG is selected from the local project folder.
Keeping the source image, SVG, Fusion design, STL, and G-code in a structured folder prevents similarly named revisions from being confused later in the workflow.
The Insert SVG command now requests a sketch plane. A horizontal origin plane is selected so the coaster geometry lies parallel to the 3D printer’s build plate.
Starting on this plane establishes the intended print orientation immediately. The pattern can later be extruded vertically to create a flat, support-free model with a large contact area against the print bed.
Confirm the SVG insertion point without closing the contextual sketch environment. Keeping the sketch open allows you to inspect and correct the dimensions before creating the solid body.
The SVG has been placed on the selected horizontal plane, and Fusion displays the Insert SVG controls. The visible settings include an X Distance of 0.000 mm, Y Distance of 0.000 mm, Z Angle of 0.000 degrees, and Scale Plane of 1.00.
The insertion handle controls the position of the pattern before it becomes regular sketch geometry. Confirming the placement without leaving the sketch keeps the geometry available for measurement and scaling.
Step 5: Remove the Fix Constraint
Measure the imported pattern before continuing. In this project, the initial diameter is approximately 61 mm, which is too small for the intended coaster.
Fusion’s Measure tool reports a distance of 61.162 mm between two selected points on opposite sides of the imported SVG. This verifies that the pattern is substantially smaller than the intended coaster diameter of approximately 100 mm.
Measuring after import is important because SVG dimensions can change during image generation, tracing, saving, or import. The result provides the reference needed to calculate the sketch scale factor.
The imported SVG appears green because Fusion automatically applies a Fix constraint. Fixed geometry cannot be moved or resized normally, so remove the Fix constraint before scaling the design.
After removing it, the sketch should become flexible enough to edit.
The complete imported pattern is selected, and Fusion reports 1,687 selections. The Fix/UnFix constraint is highlighted in the Sketch toolbar.
Imported SVG geometry is commonly fixed automatically, which prevents it from moving or scaling as expected. Removing the Fix constraint releases the selected paths so the complete Voronoi sketch can be resized as one set.
Step 6: Scale the Coaster to Approximately 100 mm
Use the Sketch Scale command to increase the SVG pattern by 60%.
This brings the coaster from approximately 61 mm to around 100 mm in diameter. A coaster of this size provides enough surface area for common cups and glasses while keeping the project compact enough for a typical desktop 3D printer.
The sketch geometry may appear blue after scaling, indicating that it is not fully constrained. Fully constrained sketches are important in complex assemblies and parametric designs because they prevent unintended movement.
For this simple one-part design, leaving the imported pattern unconstrained is a pragmatic way to avoid spending time constraining a large amount of traced SVG geometry.
The Sketch Scale command is applied to the Voronoi geometry with 1,610 entities selected, one reference point selected, and a scale factor of 1.6.
Scaling by 1.6 increases the imported diameter from approximately 61 mm to roughly 100 mm. A single reference point anchors the transformation so the entire cellular pattern expands uniformly without changing its proportions.
The geometry remains blue because it is not fully constrained. For a one-part design based on traced artwork, leaving the large set of SVG paths under-constrained avoids the unnecessary work of constraining hundreds of individual segments.
Step 7: Extrude the Pattern to 3 mm
Press E on the keyboard to leave the contextual sketch workflow and open the Extrude command.
Select the required Voronoi profiles and use these settings:
- Extrusion distance: 3 mm
- Operation: New Body
Confirm the operation to create the 3D model.
A total thickness of 3 mm keeps the coaster relatively lightweight while giving the Voronoi pattern enough height to form a usable object. Because the geometry is extruded vertically from a flat sketch, it can be printed flat without steep overhangs or support material.
Printing the largest flat surface directly against the build plate also improves adhesion and reduces the risk of the coaster moving during printing.
The selected Voronoi profiles are converted from 2D sketch geometry into a solid using Fusion’s Extrude command. The distance is set to 3 mm, the direction is One Side, the taper angle is 0.00 degrees, and the operation is New Body.
A straight 3 mm extrusion creates a flat model that can be printed directly against the build plate. The vertical walls avoid overhangs, while the broad, level underside provides reliable first-layer contact without support material.
Step 8: Increase the Thickness of the Outer Rim
Inspect and measure the coaster’s outer rim. In this design, the initial rim is thinner than intended.
After extrusion, Fusion’s Measure tool reports a minimum distance of 1.526 mm between two selected edges of the outer rim.
Although this thickness may be printable, the rim is relatively narrow compared with the 3 mm height of the coaster. Increasing its radial thickness gives the open cellular structure a more substantial perimeter and makes the edge less vulnerable to handling damage.
Select the relevant outer face and apply an Offset Face value of 1.474 mm. This brings the total rim thickness to 3 mm.
Fusion’s Offset Face command is applied to 14 selected faces around the coaster perimeter. The offset distance is set to 1.474 mm.
Adding 1.474 mm to the measured 1.526 mm width produces a target rim thickness of 3.000 mm. Offset Face modifies the existing solid directly, avoiding the need to return to the dense imported SVG sketch and edit its outer boundary.
Measure the updated geometry to confirm that the resulting thickness is correct.
The perimeter is measured again after the face offset. Fusion now reports a minimum distance of 3.000 mm between the selected rim edges.
This verification confirms that the decimal calculation and Offset Face operation produced the intended dimension. The completed rim now matches the coaster’s 3 mm extrusion height, creating a balanced cross-section around the pattern.
A stronger outer rim is useful for 3D printing because it:
- Protects the more delicate Voronoi cells
- Improves the overall rigidity of the coaster
- Reduces the likelihood of edge damage
- Creates a continuous perimeter for the slicer to follow
- Makes the printed object easier to handle
This is especially important when the central design contains many openings and comparatively narrow walls.
Step 9: Add a 0.25 mm Chamfer
Add a chamfer to the appropriate outer edges of the coaster.
A 1 mm chamfer is too large for a design this thin, so reduce the value to:
- Chamfer distance: 0.25 mm
The smaller chamfer subtly softens the edge without removing too much material from the 3 mm-thick body.
Chamfers are also practical for FDM printing. Unlike large rounded edges on the underside of a model, a small chamfer introduces the transition gradually and is unlikely to require support material. It can improve the appearance of the first few layers while making the finished coaster more comfortable to handle.
Fusion’s Chamfer command is applied to 28 edges using the Equal Distance type. Both visible distance fields are set to 0.25 mm, with tangent-chain selection enabled.
A previously considered 1 mm chamfer would remove too much material from a body only 3 mm thick. The smaller 0.25 mm value softens the selected edges while preserving the visual weight and strength of the narrow Voronoi walls.
A chamfer also creates a predictable straight transition that is easy for an FDM printer to reproduce without adding support material.
Step 10: Preview Different Color Combinations
Open Fusion’s Appearance tool and apply two different appearances to the model.
Digital appearances do not affect the exported STL geometry, but they provide a quick way to compare color combinations before using filament. In this example, yellow is used as one of the virtual colors even though yellow filament was not available when the project was recorded.
Experimenting digitally is useful because it allows you to test ideas without generating waste. If you plan to print the coaster in multiple colors, consider where the filament change will occur and whether the individual color regions require separate bodies or a manual color change at a specific layer.
Save the latest version of the Fusion design before exporting it.
Fusion’s Appearance panel is open with yellow entered in the library search. Available materials include glossy enamel and metallic yellow finishes, which can be dragged onto the body or selected faces.
Appearance settings provide a quick way to evaluate color combinations before committing filament to a print. They change only the visual representation of the model and do not alter its solid geometry or the exported STL.
Step 11: Export the Coaster as an STL File
Open the dropdown menu in the upper-left corner of Fusion and select:
File > Export
Choose STL as the file type and export the model.
Using a structured folder system for Fusion files, SVG files, STL models, and G-code can save significant time when returning to older projects or creating multiple versions of the same design.
When the export is complete, Fusion displays a link to the exported file in the upper-right corner.
The completed coaster is prepared for export from Fusion. In the Export dialog, STL Files (*.stl) is selected from the file-type list.
STL converts the solid body into a triangulated mesh that can be opened in slicing software. Before exporting, the latest Fusion version should be saved so the editable design remains available if the rim, chamfer, or overall scale needs further adjustment.
Step 12: Import the STL Into PrusaSlicer
Open PrusaSlicer and import the coaster through the File dropdown menu.
The exported coaster is brought into PrusaSlicer through File > Import > Import STL/3MF/STEP/OBJ/AMF. The separate Import STL (Imperial Units) option should not be used because the model was designed in millimeters.
The active printer profile is an Original Prusa i3 MK3S & MK3S+, with Generic PLA selected as the filament. Importing the model with the correct units preserves its intended diameter and 3 mm height.
When prompted to select the unit type, choose:
- Millimeters
Millimeters are the correct choice because the coaster was modeled using metric dimensions in Fusion. Selecting the wrong unit system could cause the model to be imported at an incorrect scale.
The coaster should appear centered on the virtual print bed. If you want to print a complete set, duplicate the model and arrange several copies on the build plate.
Leave enough space between the copies so the printer can produce clean perimeters around each coaster.
The imported coaster is selected on the virtual build plate, and the context menu displays options including Add instance and Set number of instances.
Adding instances makes it possible to print several identical coasters in one job without exporting multiple STL files. The object information confirms approximate dimensions of 100.53 × 100.21 × 3.00 mm, closely matching the intended 100 mm diameter and 3 mm thickness.
Step 13: Select a Print Preset
PrusaSlicer provides extensive control over layer height, perimeters, infill, speed, supports, and filament use. However, the built-in presets provide a practical starting point.
Choose a preset based on your priorities:
- A finer layer height for improved visual quality
- A larger layer height for faster printing
- Additional perimeters for stronger Voronoi walls
- Settings appropriate for your chosen filament
The coaster is designed to lie flat on the print bed. Its flat orientation provides a large contact area for adhesion, while the vertical extrusion means that the pattern should print without support material.
Before slicing, inspect the preview for any Voronoi walls that may be narrower than your printer can reproduce.
Three instances of the Voronoi coaster have been arranged on the Prusa i3 MK3S build plate. The Print settings menu is open, with 0.20 mm QUALITY selected.
This preset provides a practical balance between surface quality and printing time. All three models fit within the available build area, but their spacing should still be checked to ensure that the perimeter toolpaths do not overlap
Step 14: Slice and Export the G-Code
Click Slice Now to generate the G-code required by the 3D printer.
PrusaSlicer will calculate information such as:
- Estimated print time
- Filament consumption
- Layer count
- Toolpaths
- Perimeter placement
After slicing, PrusaSlicer displays the generated toolpaths and summarizes the material and time required for all three coasters. The visible estimates are:
Used filament: 20.84 g
Filament length: 6.99 m
Filament volume: 16,808.31 mm³
Estimated cost: 0.53
Estimated normal-mode printing time: 3 hours 23 minutes
The preview legend separates perimeters, external perimeters, infill, solid infill, and other feature types by color. Reviewing these values before exporting makes it easier to compare presets and estimate the cost of producing a complete coaster set.
Use the layer preview to simulate the print and inspect how the coaster builds from the first layer upward. Pay particular attention to the narrow Voronoi walls and outer rim.
If PrusaSlicer omits part of the pattern, the affected wall may be too thin for the selected extrusion width. Return to the model or adjust the relevant slicer settings before printing.
When you are satisfied with the preview, select Export G-code and save the file to your preferred location.
The G-code preview is positioned at 3.00 mm, corresponding to the fifteenth and final layer of the coasters. The orange and yellow paths show how the printer will form the outer rims and narrow Voronoi walls.
The preview can be moved through the print layer by layer to verify that every part of the pattern produces a continuous toolpath. This is particularly important for traced artwork because walls that are narrower than the configured extrusion width may be omitted or printed inconsistently.
Once the geometry and toolpaths have been verified, Export G-code creates the printer-ready file.
Step 15: 3D Print the Voronoi Coaster
The coaster in this project was printed on a Prusa i3 MK3S+.
The final print demonstrates how an AI-generated image can be transformed into functional 3D-printable geometry through a combination of image generation, vector tracing, CAD modeling, and slicing.
The same workflow can be adapted to other projects, including:
- Decorative panels
- Trivets
- Wall art
- Signs
- Lampshades
- Container lids
- Patterned product inserts
The most important part is ensuring that the generated pattern is compatible with the physical limitations of FDM printing. Clean edges, printable wall thicknesses, a flat build orientation, and support-free geometry make the design much easier to manufacture successfully.
Key Takeaways
- Generate the Voronoi pattern in black and white to improve edge detection.
- Tell the AI that the design will be 3D printed so it avoids excessively thin walls.
- Use Edge Detection in Inkscape’s Trace Bitmap tool.
- Remove Fusion’s automatic Fix constraint before scaling the imported SVG.
- Scale the original 61 mm pattern by 60% to reach approximately 100 mm.
- Extrude the coaster to 3 mm as a New Body.
- Offset the outer face by 1.474 mm to create a total rim thickness of 3 mm.
- Use a subtle 0.25 mm chamfer instead of the oversized 1 mm option.
- Print the coaster flat for good build-plate adhesion and support-free manufacturing.
- Inspect the sliced toolpaths to confirm that all Voronoi walls can be printed.
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If you enjoyed creating a Voronoi coaster in Fusion, these related tutorials explore other ways to turn repeating geometry into functional, 3D-printable products.
Together, these projects extend the pattern-based workflow used for the Voronoi coaster into honeycomb structures, patterned surfaces, fitted components, and practical models prepared for 3D printing.
Chapters in this Fusion tutorial:
0:17 What You’ll Learn in This 3D Printing Tutorial
00:27 Generate a Voronoi Coaster Design Using AI Tools
00:55 Convert AI Image to SVG File with Inkscape for 3D Printing
01:30 Use Inkscape Edge Detection for Clean SVG Tracing
02:00 Import and Scale SVG in Autodesk Fusion for 3D Modeling
02:34 Fix Sketch Size and Scale for a Perfect Coaster Fit
03:22 Extrude Voronoi Pattern to Create a 3D Printable Model
03:55 Adjust Coaster Thickness Using Offset for PLA Prints
04:40 Add Chamfers for Stronger and Sleeker 3D Prints
05:08 Test PLA Filament Colors Digitally Before Printing
05:53 Save Project and Export STL File for Your 3D Printer
06:38 Set Up the STL File in PrusaSlicer for PLA or PETG
06:55 Arrange Multiple Coasters and Optimize Slicer Settings
07:20 Export G-code and Preview Your Voronoi Coaster Print
07:52 Tips for Selling 3D Prints Online + Final Thoughts