Working with STL and mesh files in Shapr3D

What is a mesh file?

Overview

Mesh models are made up of polygons formed by vertices, edges, and planar faces. Unlike solid CAD models with mathematically defined curved surfaces, mesh models approximate curves using flat polygonal faces.

A higher number of polygons can create a smoother and more detailed appearance, while fewer polygons result in a simpler, more faceted model.

Mesh geometry is commonly used in 3D printing, manufacturing, and 3D scanning. However, editing mesh models differs from working with solid CAD geometry.

Mesh tolerance and quality

When converting a CAD model into a mesh, the curved surfaces of the original model are approximated using polygons. The accuracy of this approximation depends on the mesh tolerance.

Tolerance defines the maximum allowed deviation between the original CAD geometry and the generated mesh.

• Smaller tolerance: Produces more polygons and a more accurate representation of the original geometry.
• Larger tolerance: Produces fewer polygons and a less detailed mesh, typically resulting in a smaller file.

Import mesh files into Shapr3D

You can import STL files into Shapr3D as mesh bodies.

When importing an STL file, the Import Preferences dialog lets you specify the measurement unit used by the model.

Measurement unit

Select the measurement unit used by the imported model. Since STL files don't store measurement units, choosing the correct unit ensures that the model is imported at the intended scale.

Work with mesh bodies in Shapr3D

Supported operations

You can use imported mesh bodies as references for your designs or modify them using supported modeling tools.

In Shapr3D, you can:

• Use meshes as references: Position imported mesh models alongside solid bodies to guide your modeling workflow.
• Transform mesh bodies: Move, rotate, and scale imported mesh geometry.
• Apply Boolean operations: Combine, subtract, or intersect supported mesh geometry with other bodies.
• Visualize models: Apply materials and explore the appearance of imported mesh bodies in Visualization.

Boolean operations with mesh bodies

You can use Boolean operations with closed mesh bodies. Open or sheet meshes cannot be used for these operations. When performing Boolean operations on a mesh body, the resulting geometry remains a mesh.

For example, you can create solid bodies from sketches and use Subtract to remove material from an imported mesh model.

For more information about combining, subtracting, and intersecting bodies, visit Boolean operations.

Understanding STL units

How STL units work

STL is a widely used mesh file format for 3D printing and rapid prototyping.

STL files store the surface geometry of a model as a polygonal mesh, but they don't contain information about measurement units.

This means the same STL file can be interpreted at different scales depending on the units selected during import.

Avoid unit mismatches

For example, if an STL model was created in inches but imported into another application using millimeters, the model may appear significantly smaller than intended.

To avoid scaling issues:

• Use consistent measurement units throughout your design and manufacturing workflow.
• Select the correct measurement unit when importing STL files into Shapr3D.
• Match the export unit in Shapr3D with the expected unit in your slicer or other software.
• Verify the dimensions of your model after transferring it between applications.

Export mesh files

You can export your Shapr3D models as STL files for 3D printing and other applications.

When exporting an STL file, you can configure the following settings:

• Resolution: Choose Low, High, or Custom to control the level of detail in the exported mesh. Custom lets you adjust Angle Tolerance and Deviation Tolerance.
• Include Mesh Bodies: Choose whether to include existing mesh bodies in the export.
• Output Format: Select the STL output format.
• Units: Set the measurement unit for the exported file. Since STL files don't store unit information, use the same unit in your slicer or receiving application.

Higher-resolution meshes generally preserve more geometric detail but can produce larger files.