Shrink Wrap

When you’ve finished the retopologizing process, you can use Shrink Wrap to increase the accuracy of the mesh with respect to the reference mesh. You’ve been working in Control Mesh display as you created the retopo mesh, but switching to SubD display, you will see that the SubD version, by its very nature, shrinks inward to produce its curvature continuous surface. Because the subdivided version is what is used to generate the CAD model, the Shrink Wrap step is an important one.  

The Shrink Wrap command brings the subdivided mesh back out to the reference mesh’s surface. A single level of internal subdivision may be sufficient depending on the density of the retopo mesh and the amount of detail you want to retain from the reference mesh.  A second level of subdivision will be more accurate but may reveal unwanted detail.  A third level of subdivision is rarely required and can take a long amount of time to calculate. Shrink Wrap works only on constrained vertices.  

The retopo’ed mesh in Control Mesh display, upper left, sucked inward in the SubD display mode, upper middle, pushed out to the reference mesh surface after shrink wrap, upper right

Shrink Wrap (formerly Interpolation)

Shrink Wrap pulls the SubD down closer to the mesh by embedding information into the mesh to make the subdivision converge to the mesh.  The number box controls the number of subdivisions to use in the shrink wrap process.

Default Shrink Wrap keeps the shrink wrap in a table which often gets destroyed during editing operations.  This was the previous default.

Bake into Offset will subdivide the mesh and perform an offset such that the subdivided mesh of the offset converges down to the reference mesh.   This operation removes all of the constraints and you are free to edit the resulting mesh in any way.

Bake into Level of Detail will move the shrink wrap table into the LOD table.  Most operations such as Extrude support the LOD table, thus it is much more editable than the default option.    

The top left image shows the default of 0 levels in Shrink Wrap.  The top right image shows shrink wrapping using 2 levels.  Note the much higher accuracy.

The left image below shows Bake into Level of Details.  Note that the number of polygons has not changed with this operation.  The right image shows Bake into Offset with 1 level of subdivision.  Note that there are now 4 times as many faces.

See also:

Update Shrink Wrap, Clear Shrink Wrap

Check for Self-Intersecting Faces
Distance Display

Created with the Personal Edition of HelpNDoc: Create iPhone web-based documentation