Remap a generic field of scalar values into a signed distance field.

Implicit modeling represents geometry as a 3D field of scalar values. In general, positions where the field is equal to zero are on the surface of the object. By convention, negative scalar values are inside the object, and positive scalar values are outside the object.

It is important to note that not all scalar fields have the signed distance field property. In a signed distance field, the scalar value at each position in space encodes the distance to the closest point on the surface. Again, negative values are on the inside of the object and positive values are on the outside. Some operations, such as Boolean Combine, Subtract and Intersect, can break the signed distance property of a field.

Some operations require an accurate signed distance field to function correctly. Examples include offsets, shells, and fillets. If the signed distance field property is important to your downstream design process, remapping the field will convert the current field for the body into a signed distance field.

  1. On the Implicit Modeling ribbon, select the Remap tool.

    Tip: To find and open a tool, press Ctrl+F. For more information, see Find and Search for Tools.
  2. In the modeling window, select an implicit body whose field you would like to remap.
  3. Optionally activate a Section Plane and the View Field option so that you can see the contours of the field inside the model.
  4. Click OK to accept the remapped field.

As an illustrative example, let's consider the Boolean Combine operation on an overlapping sphere and cube, as shown below.

Using the View Field tool, we can see the underlying contours of the field immediately after the Boolean Combine operation. At first glance, this field looks fine and, in many cases, this is a perfectly valid field. However, it is not a signed distance field. If you consider each white contour, you can see that some contours are not equidistant to the surface (black contour).

In many cases, it is okay to proceed with the design despite the fact the field is not a signed distance field. However, let's look at what happens when we apply a large inward offset of the geometry. You can see that the sphere and the cube are each being inwardly offset independently of each other, which is arguably not the intent of the designer.

If we perform a remap on the Boolean Combine object (combined sphere and cube), we can see that the contours are very different. The white contour lines are now a each a constant distance from the surface (black contour), and they step inwards in the expected fashion.

If we repeat the large inward offset, the expected result is presented: a shrunken version of the Boolean Combine object.