Creating Circular Patterns

Open the Pattern2.CATPart document.

1. Click Circular Pattern .

2. Select the element to replicate as a pattern.

   Here we selected the multi-sections surface.

   The Circular Pattern Definition dialog box is displayed.

3. Click the Reference element field and select a direction to specify the first direction of creation, that is the rotation axis (Line.2).

   To define a direction, you can select a line, an edge or a planar face. Should you select a face, the rotation axis would be normal to that face.

   You can click Reverse to inverse the rotation direction.

4. Define the Axial Reference by choosing the Parameters type:

   Instance(s) & total angle: the number of patterns as specified in the instances field are created, in the specified direction, and evenly spread out over the total angle.
   Instance(s) & angular spacing: the number of patterns as specified in the instances field are created in the specified direction, each separated from the previous/next one of the angular angle value.
   Angular spacing & total angle: as many patterns as possible are created over the total angle, each separated from the previous/next one of the angular angle value.
   Complete crown: the number of patterns as specified in the instances field are created over the complete circle (360°deg).
   Instances & unequal angular spacing: the number of patterns as specified in the instances field are created using a specific angular spacing between each instance.
   Angular spacing values are displayed between each instance.
   To edit the values between each instance, you need to edit them individually. Select the angular spacing of interest, then choose one of the methods described hereafter: For instance, if you wish to change 72 degree for 100 degree for the angular spacing selected as shown in our picture, you can:
   double-click the angle value in the 3D geometry. This displays the Parameter Definition dialog box in which you can enter the new value. directly enter the new value in the Angular spacing field of the Circular Pattern Definition dialog box.
   	If you set Instance(s) & total angle or Angular spacing & total angle parameters, note that you cannot define the angle by using formulas.
   Now you are going to add a crown to this pattern.

5. Click the Crown Definition tab, and choose which parameters you wish to define the crown.

   This figure may help you define these parameters:

   Circle(s) & crown thickness: you define the number of circles and they are spaced out evenly over the specified crown thickness Circle(s) & circle spacing: you define the number of circles and the distance between each circle, the crown thickness being computed automatically Circle(s) spacing & crown thickness: you define the distance between each circle and the crown thickness, and the number of circles is automatically computed.

   For instance, using the values described above for the Angular spacing & total angle option, you could define the crown as:

   Note that a few patterns are created beyond the surface.

   You can delete the instances of your choice when creating or editing a pattern. To do so, just select the points materializing instances in the pattern preview.

   The instance is deleted, but the point remains, as you may wish to click it again to add the instance to the pattern definition again.

6. Click More>> to display further options:

   These options let you position the instances in relation to the first selected element.
   Using these options, you can change the position of the selected element within the crown. For example, if you set the Rotation angle parameter to 30° and you uncheck the Radial alignment of instance(s) option, this is what you obtain: the initially selected element has moved 30° from its initial location, based on the rotation direction, and all instances are normal to the lines tangent to the circle.
   The Simplified representation option lets you lighten the pattern geometry, when more than 15 instances are generated. What you need to do is just check the option, and click Preview. The system automatically simplifies the geometry:
   Not simplified geometry	Simplified geometry
   You can also specify the instances you do not want to see by double-clicking them . These instances are then represented in dashed lines during the pattern definition and then are no longer visible after validating the pattern creation. The specifications remain unchanged, whatever the number of instances you view. This option is particularly useful for patterns including a large number of instances.
   When checking Radial alignment of instances, all instances have the same orientation as the original feature. When unchecked, all instances are normal to the lines tangent to the circle.

7. Click OK to create the pattern.

   The pattern (identified as CircPattern.xxx) is added to the specification tree.
   	Patterning User Features (UDFs) is not allowed. You can cut or copy circular patterns provided that it belongs to the same body.

Patterning Volumes

1. Click Circular Pattern .

2. Select the element you wish to replicate as a pattern.

   The Circular Pattern Definition dialog box is displayed.

3. Click the Reference element field and select a direction to specify the first direction of creation.

4. Define the Axial Reference by choosing the Parameters type:

5. Click OK to create the pattern.