Applies to 2022.0 Update and later

Working with CAD files natively

Loading and saving CAD files, and managing a CAD file's parametric nature

When working with CAD files, or parametric parts, your workflows in Netfabb remain largely unaffected as long as you do not change part shape by operations such as cutting or mirroring. When attempting to perform such actions, you are warned with a dialog to tell you that this will drop the parametric information from the part. You may disable the warning dialog by setting Settings > Settings > General > Warn if solid model associativity will get lost to No. Dropping the parametric information fixates the current tessellation permanently into the part's mesh.

Netfabb has no function to generate parametric surfaces from triangle mesh ("convert mesh to CAD"). We recommend to use Fusion for that instead.

Jump to:

To recognize a parametric part
To drop the parametric data
To load a CAD file for native use
To export parts as parametric CAD file
To retessellate a part
To create and modify presets

To recognize a parametric part

There are several indicators to tell a parametric part from a mesh part.

Check the part's icon in the project tree. Parametric parts are represented with a wireframe cylinder, pure mesh parts with a shaded circle.
Select the part and check Modify > Tesselation. If the items Retessellate model or Remove parametric association are grayed out, it is a pure mesh part.
Select the part and check File > Export part > as parametric model file (SAT, STEP, IGES). If this option is grayed out, it is a pure mesh part.

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To drop the parametric data

You may manually force to drop the parametric dataset and turn the CAD part permanently into a triangle mesh at any time by choosing Modify > Tessellation > Remove parametric association.

Caution: This is the last opportunity to retessellate before dropping the parametric information and export.

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To load a CAD file for native use

Loading a file does not distinguish files of mesh or parametric nature, so opening either takes only one step:

Choose File > Add part from the main menu.

"Native use" means that Netfabb retains the parametric nature and only generates triangles as necessary, such as support generation, while leaving the part itself untouched.

An alternative loading method is available that tessellates the part and irreversibly drops the parametric nature. To learn more about this, read the dedicated article: To import CAD files as meshes

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To export parts as parametric CAD file

Note: Export to CAD formats is available only for those parts that were loaded as CAD file and still retain their parametric data.

In Netfabb, select the parts you want to export.
Click File > Export part > as parametric model file (SAT, STEP, IGES), and select the CAD format you want to export to, SAT, STEP, or IGES.
The Export parts dialog box opens.
Adjust export settings for the parts.
Enter a name and folder for your file and click OK.

Note: If this export option is grayed out, it is not a parametric part and you cannot export it to SAT, STEP, or IGES.

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To retessellate a part

To retessellate the part for a workflow step that could benefit from a different level of mesh resolution, choose Modify > Tesselation > Retessellate model. This provides a dialog to choose from tessellation presets, or to create custom presets.

The same part, tessellated with two different presets

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To create and modify presets

Netfabb comes with a set of tessellation presets as well as a variant for each that includes repair. To create and modify presets, do so during retessellation, or choose Settings > Settings > Tessellation setting library.

Here, create and edit duplicates from the default presets (these cannot be modified). Provide a name and make your selection from these options:

Parameter	Description
Normal tolerance	The smaller the tolerance, the more triangles will be generated to replicate curvature of a surface.
Surface tolerance	The smaller the tolerance, the more triangles will be generated to replicate a face shape in general
Maximum edge length	Limits the length of triangle edges
Maximum grid lines	Grid lines are an internal method to aid in triangle generation.
Minimum grid lines
Smoothing mode	Applies smoothing to no, surrounded, or all interior mesh nodes.
Triangulation level	Sets the level of triangulation in some edge cases.
Intersection mode	Intersections of grid lines may be used to provide additional points for meshing.
Postprocessing mode	Choose a preference for regular triangles or quads, if required.
Calculation mode	Prefer approximation and faster calculation, or higher accuracy and increased calculation cost.
Repair mode	Select from six options for post-tessellation repair, including Netfabb's built-in default repair scripts.

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