Healing Phases

Body healing is a four-step process. The required steps are listed in order below:

Preprocessing

This phase performs initial cleanup of a model to be healed. In this phase, model inaccuracies, such as zero-length edges, sliver faces, redundant faces and duplicate vertices, are removed. Also, face normals and negative face areas are corrected in this phase.

Geometry Simplification

This phase converts geometry into their corresponding analytic forms (e.g. arc, cone, plane, sphere, torus, etc.) wherever possible. The geometry is analyzed prior to simplification. The analysis determines a simplification tolerance. Howeve,r you may override this value. 

This step can reduce model size significantly and optimize calculations appropriately for further speed increases. This phase also effectively converts circular and linear spline edges to arcs and line to aid in dimensioning and verification. 

Be aware that even though this phase reduces complexity of some ACIS based parts, it is most useful for spline faces imported from other applications such as IGES or FastSURF. In such a case, you are healing, because you want to stitch faces together. 

Using this phase to simplify valid solid models is NOT recommended, because it simplifies to within a tolerance, and thus may change the geometry.

Stitching

This phase provides the means to stitch a set of faces together to form a single sheet or solid body. Stitching involves the pairing of vertices and edges. In the case of a surface model that lacks topology, such as from IGES, this phase adds topology to the model. The geometry is analyzed prior to being stitched. The analysis determines a tolerance to be used when deciding whether or not two surfaces should share an edge or vertex. However, you may override this value and supply your own.

If the original surfaces are error free, meaning they completely enclose a volume, contain correctly pointed normals, and match within the ACIS tolerance (10e-6 default), a closed solid body will be formed.

Geometry Building

This phase heals inaccuracies in the model. Geometry is built, as necessary, to correct the gaps in the model. The analysis stage calculates a geometry-building tolerance based on the model. However, you may override this value and supply your own.