Splitting Topology

Contents

• 34.1 Introduction
• 34.2 Splitting an edge at a specified parameter
• 34.3 Splitting a face along a constant parameter line

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34.1 Introduction

The following functions are used to split topological entities:

You can use these functions to create additional edges or faces in a model. For example, Parasolid does not split topology at periodic boundaries by default - a cylindrical face is not given a “seam”. You can call PK_FACE_split_at_param to create a seam, as shown in Figure 34-1.

Figure 34-1 Splitting a periodic face in order to produce a seam

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34.2 Splitting an edge at a specified parameter

PK_EDGE_split_at_param receives the following arguments:

edge 

param 

PK_EDGE_split_at_param returns the following arguments:

PK_EDGE_split_at_param accepts both tolerant and accurate edges. In order for the edge to be split successfully, the following must all be true:

• param must be inside the range of edge
• param must not evaluate to a point coincident with any vertex on edge
• edge must have attached geometry

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34.3 Splitting a face along a constant parameter line

PK_FACE_split_at_param receives the following arguments:

face 

param 

param_dir 

PK_FACE_split_at_param returns the following arguments:

n_new_edges
 

new_edges
 

n_new_faces
 

If the face is split successfully, then new edges are created. This in turn may lead to the creation of new faces. If new faces are created, the original face lies on the right of one of the new edges. All new edges go in the direction of param_dir . New edges are those that are imprinted onto the face during the operation. Derived edges, that are created as a result of splitting existing edges, are not returned in new_edges .

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