Convert to Implicit Geometry

Convert parts, surfaces, and curves to implicit objects. You can select CAD, PolyNURBS, meshes, or optimized parts, surfaces, or curves.

Converting to implicit geometry allows objects to undergo implicit versions of processes such as offset, Boolean, fillet, and smooth. Objects can also be turned into lattices, and they can be used to create fields that control other parameters such as lattice relative density. All nonimplicit parts are automatically converted if used directly in another implicit context.
The output is a Signed Distance Field (SDF) for the converted geometry, with negative scalar values inside the object and positive scalar values outside the object (the surface exists at positions with scalar values of zero).
Note: Converting nonsolid objects will technically produce an Unsigned Distance Field (UDF) since there is no interior volume that will have negative field values. Offsetting these fields outward will produce a SDF as it will create a solid volume around the surface(s) or curve(s).
The process begins with a BRep (NURBS), subdivision, or tessellated surface mesh (e.g. STL) geometry such as the BRep crank model shown below.

Based on the Visualization Quality setting that is active in the Implicit Modeling ribbon, the converted object will be less or more accurate and sharp. The next image shows the result of the conversion using the Medium Visualization Quality setting. This model will compute very quickly, but note the rounded edges and loss of sharp features in general.

To produce a more accurate Implicit reproduction of the original BRep model, the following image was created using the Very High Visualization Quality setting. Note the marked improvement in the sharpness of features, such as edges. This quality comes at the cost of a longer compute time, and a general increase in memory allocation to manipulate this object. It is recommended that you select a Visualization Quality that balances the trade-off between visual quality and compute time on their machine. You can always design at a lower Visualization quality and then increase this value periodically to check the appearance at higher quality settings.

This final image shows the converted implicit model overlaid on a sectioned view of its Signed Distance Field (SDF).

Note: For a much more detailed discussion around handling quality when converting into and out of Implicit Modeling, please see Visualization Quality and Mesh Settings.
  1. On the Implicit Modeling ribbon, select the Convert tool.
    Tip: To find and open a tool, press Ctrl+F. For more information, see Find and Search for Tools.
  2. On the Convert to Implicit guide panel, select the appropriate tab for the type of object(s) required for the conversion.


    • Parts: Allows selection of nonimplicit parts.
    • Surfaces: Allows selection of surfaces on multiple parts.
    • Curves: Allows selection of curves on multiple parts.
  3. Optional: For Visualization Quality, select from Low to Very High quality, which corresponds to a low to very high density of elements. A higher quality produces sharper geometry features but is more computationally intensive. When creating a complicated function, it’s recommended to work using a lower quality and then switch to a higher quality after the function is complete.
  4. Select one or more parts, surfaces, or curves to convert to implicit bodies. A new implicit object will be created for each converted part; multiple surfaces or curves will be converted into a single implicit object.
    Note: Convertible formats include BRep (e.g., Parasolid, STEP, etc.), PolyNURBS (subdivision surfaces), and polymesh (tessellated surface meshes including .stl, .obj, .3mf, etc.). It is also possible to convert the geometry results arising from simulation and optimization workflows, such as topology optimization results.
  5. Click OK.