About Pattern Regeneration Options

Creo defines patterns based on the complexity of features and surfaces involved in the pattern creation. Moreover, the system makes certain assumptions for each type of pattern.

The less complex the pattern is, the more assumptions can be made and the faster the pattern is created. Patterns are categorized into three types, using the options Identical, Variable, and General (available on the Options tab).

Identical patterns, the most simple, have the following restrictions:

• No instance intersects the edges of the placement surface, any other instance, or any feature other than the placement surface.

Identical patterns regenerate the fastest of the three options. For an identical pattern, the system generates the first feature, then copies it exactly, including all the intersections.

In identical patterns, the system does not check to make sure that there will be no overlap among the instances of the pattern. This kind of check would slow the regeneration of the pattern and defeat the advantage of using an identical pattern. You must check for overlaps yourself. To avoid having to check yourself, use a general pattern.

Variable patterns are more complicated than identical patterns. The system makes the following assumptions about variable patterns:

For variable patterns, geometry for each feature is generated individually, then all the intersections are generated at one time.

A variable pattern intersects part geometry as a whole group. As a result, if you were to use a varying pattern on a feature extruded up to the next surface, there would be only one creation direction for determining which is the next surface and you could get undesired results. To avoid this, use only general or identical patterns with features extruded up to the next surface.

General patterns allow you to create the most complex patterns.

The system makes no assumptions about the instances of general patterns. Therefore, the system calculates the geometry of each individual instance and intersects each feature separately.

Use this option when you expect the feature to touch other instances, intersect itself, or cross surface boundaries as it gets patterned. General patterns are required even if instances intersect inside the base feature and the intersection is not visible.