| You may
need to duplicate the whole geometry of one or more features and to
position
this geometry on a part. Patterns let you do so, and by the way accelerate
the creation process. The application allows you to define three types
of patterns:
This document deals with the following:
You can also find information about patterns and updates by
reading
Optimizing Part Design Application, Patterns. |
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This task shows you how to duplicate the geometry
of one pocket right away at the location of your choice using a
rectangular pattern. Then, you will learn how to modify the location of
the initial feature. |
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Open the
RectangularPattern.CATPart
document. |
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Select the feature you wish to copy, that is the pocket
as shown:
-
Click the Rectangular Pattern
icon
.
The Rectangular Pattern Definition
dialog box that appears displays the name of the geometry to pattern.
If you click the Rectangular Pattern icon
prior to selecting any geometry, by default, the object to be patterned
is the current solid. For more information, refer to
Patterning Current Solids.
If you change your mind and decide to
pattern the current solid, click the Object
field and use the Get current solid contextual command.
If you want to create patterns of multiple elements, press Ctrl,
select the required elements from the specification tree, and then click
Rectangular Pattern...
.
The number of selected elements appears in the Object box.
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- You can also click
beside the Object box, and select the required elements
from the specification tree. The selected elements appear in the
list and the number of elements appears in the Object
box.
- You can create Part Design features, such as
pads, pockets, shafts, grooves, and holes, on the fly while
creating a pattern. To do so, right-click the Object
box and select the required command.
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Each tab is dedicated to a direction you
will use to define the location of the duplicated feature. In this task,
you will first set your specifications for the first direction.
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Reference Direction
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Click the Reference element field
and select the edge as shown below to specify the first direction of
creation.
An arrow is displayed on the pad. If needed, click the Reverse
button or click the arrow to modify the direction.

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- To define a direction, you can select an edge or a planar face.
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Let the Instances & Spacing options to define
the parameters you wish to specify.
The parameters you can choose are:
- Instances & Length
- Instances & Spacing
- Spacing & Length
- Instances & Unequal Spacing:
distinct spacings can be assigned between instances.
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| Choosing
Instances & Spacing
dims the Length field because the application no longer
needs this specification to space the instances. |
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If you set Instances & Length or
Spacing & Length parameters, note that you cannot define the
length by using formulas. |
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Enter 3 as the number of instances you wish to obtain in
the first direction.
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Deleting the instances of your choice is possible
when creating the pattern. In the pattern preview, just select the
points materializing instances. Conversely, selecting these points again
will make the application create the corresponding instances. |
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Define the spacing along the grid: enter 14 mm.
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Defining the spacing along the grid and length of
your choice would make the application compute the number of possible
instances and space them at equal distances. |
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Now, click the Second Direction tab to define
other parameters.
Note that defining a second direction is not compulsory. Creating a
rectangular defining only one direction is possible.
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Click the Reference element field and select
the edge to the left to define the second direction.
If necessary, click Reverse to make the arrow point in the
opposite direction.
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Let the Instances & Spacing option: enter 3
and 10 mm in the appropriate fields.
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Optional: Select the Identical instances in
both directions check box if you want to create a pattern with
equal instance in both directions.
A preview of the pattern appears in the geometry.
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Notes: |
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- If you select the
Identical instances in both directions check box, a
rectangular pattern is created with the number of instances
provided in the
Instance(s) box in the First Direction tab.
In addition, the number of instances in the second direction
is set to the number of instances in the first direction. If
you change the number of instances in the first direction,
the number of instances in the second direction is updated
automatically.
- The Identical instances in both directions
check box is enabled only after you define the second
direction.
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Click Preview to make sure the pattern meets
your needs.
Additional pockets will be aligned along this second direction.
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Click OK to repeat the pocket's geometry nine
times.
This is the resulting pattern. RectPattern.1 feature is
displayed in the specification tree.
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Let's now edit the pattern to make it more complex:
double-click the pattern to display the dialog box.
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Click the More button to display the whole
dialog box.
The options available let you position the pattern.
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To modify the position of the pockets, enter 5 degrees as
the rotation angle value.
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Click Preview.
You can notice that all pockets have moved slightly:
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Now, modify the location of the initial pocket. To do so,
enter 2 in the Row in Direction 1 field.
The application previews how the pattern will be moved. It will be moved
along the direction as indicated:
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Finally, enter 2 in the Row in Direction 2
field.
The application previews how the pattern will be moved. It will be moved
along these two directions defined in steps 17 and 18:
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The Simplified representation option
lightens the pattern's geometry. What you need to do is just check the
option and double-click the instances you do not want to see. The
instances are then represented in dashed lines during the pattern
definition and then are no longer visible after validating the pattern
creation.
When the Simplified representation option is on, because the
pattern's geometry representation is modified, the part mass is modified
too.
This option is particularly used for patterns including a large number
of instances. |
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Click OK.
The application has changed the location of all pockets. Only four of
them remain on the pad.
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Instances and Unequal Spacing
You can assign specific spacing values between each instance by
proceeding as follows:
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Create a new pattern for the purpose of this task: select
Pocket.1 as the object to pattern, and first set the Instances &
Length parameter using the length values as shown here:
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Set the Instances & Unequal Spacing parameter
for the first direction.
Spacing values are displayed between each instance.
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To edit the values between each instance, you need to
edit values individually. First, select the spacing of interest if not
already done.
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Then, choose one of the methods described hereafter: For
example, if you wish to change 10mm for 17mm for the selected spacing,
you can:
- double-click the length value in the geometry area. This
displays the Parameter Definition dialog box in which
you can enter the new value.
- directly enter the new value in the Spacing field of
the Rectangular Pattern Definition dialog box.
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Repeat the operation for the other spacings.
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Click OK when done.
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Create a Staggered Pattern |
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You can create the specific staggered pattern configurations by offsetting
the alternate rows of the pattern by certain distance. |
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Create a rectangular pattern as shown below:

Note: The reference row is marked in the red color. |
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Double-click RectPattern.x
in the specification tree.
The Rectangular Pattern Definition dialog box appears.
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Click More>> for more information.
The options available let you stagger the pattern.
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Select the Staggered check box in the
Staggered Pattern Definition
area.

By default, the
option is
selected to keep the number of instances in the reference row more than
its adjacent row.
Note: You can click
to keep
the number of instances in the reference row less than its adjacent row.
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Perform any one of the following actions to define
offset spacing. In the Stagger Step box, type the value to
specify the offset between the alternate rows of the pattern.
- In the Stagger Step box, type the value to
specify the offset between the alternate rows of the
pattern.
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The stagger step must be less than the spacing
defined for the second direction. |
- Select the Set half of spacing
check box to set the stagger step value to half of the
spacing in the second direction.
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Notes: |
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- The stagger step value is set to half of the spacing in the
second direction.
- If the Set half of spacing check box is selected,
the stagger step value depends on the spacing in the second
direction. If the spacing in the second direction is changed,
the stagger step value is updated accordingly.
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Click OK.
The staggered pattern is created.

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Removing Instances
Remember that clicking an instance once removes the instance from the
specifications. Clicking once or double-clicking an instance does not
lead to the same result then. |
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It is possible to create Cartesian patterns with
variable steps. To do so, you need to define formulas. For more
information, refer to Knowledge Advisor User's Guide Version 5. |
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- During your design, you may need to rework instances specifically.
You will then have to use the Explode contextual command to
delete your pattern while keeping geometry. For more information, refer
to Exploding Patterns.
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Complex Patterns
You can pattern a list of Part Design features
by proceeding as follows:
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Multi-select the features to be duplicated.
These features must belong to the same body.
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Click the Rectangular Pattern icon
.
The features are indicated in the Object field.
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Set the parameters you need as shown in the task above.
These rules are to be kept in mind before patterning a list of features.
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The pattern does not give appropriate results if the list of features to be
patterned contains elements with non-movable sub-elements (wireframe
geometry like Point, Line, Plane or B-Reps like Edge, Face etc.). In
this case following warning message is displayed:
The list of features to be patterned
contains elements with non-movable sub-elements (i.e. wireframe
geometry, edges etc.). Consequently, the Pattern operation may produce
wrong results. (In case you want to pattern a User Feature, launch
pattern command first and then select the User Feature for stable
results.) Do you want to continue?
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Editing a List of Features
Editing a list of features consists of adding or removing
features from the list. To do so,
beside the Object field and select the feature of interest
from the specification tree to add it to the list of features. To remove
a feature, select it from the list and click
Remove.
Patterning Current
Solids
A current solid is composed of one or more features belonging to the
same body. It is the result of the operations as mentioned in the
specification tree, the last operation being the current one. For more
about current features, see
Scanning a part
and defining local objects.
To pattern a current solid, just click the Rectangular Pattern
icon
.
There is no need to select any geometry. By default, the object to
pattern is the current solid. You then just have to enter your
specifications in the dialog box.
If you change your mind and decide to pattern a feature, click the
Object box and select the feature of your choice. However, if the
object to pattern bag
is already opened, select the current solid, click Replace
and then click the new feature from the specification tree.
In the following example, the current solid is the result of one pad and
one hole. |
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The instances created via the Pattern
command are composed of pads and holes only. |
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When you pattern multi-pads or multi-pockets, the
entire current solid is transformed.
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You cannot transform a patterned list of features
into a patterned current solid and vice-versa.
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Patterning User Defined Features (UDFs)
There are two ways of patterning a
User
Defined Feature. The order of selection affects the availability of
the
Keep specifications option:
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Method 1
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Click Rectangular Pattern
.
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Select the user defined feature (UDF) you want to
duplicate.
Here the pattern is treated as a single feature. Keep specifications
is disabled and dimmed.
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Method 2
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Select the user-defined feature UDF you want to
duplicate.
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Click Rectangular Pattern
.
The application treats the pattern feature as a
complex pattern, that is a pattern made
from a list of diverse features. Keep specifications
is enabled and dimmed. The created pattern you create keeps the UDF
specifications.
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- You can only pattern UDF solids composed of one single feature.
- Patterning UDFs is allowed in Part Design, not in Generative Shape
Design.
- Selecting the pattern capability then the UDF is the method we
recommend for best performance optimization.
- If the UDF contains elements with non-movable sub-elements
(wireframe geometry like Point, Line, Plane or B-Reps like Edge, Face
etc.), the pattern may produce wrong results. In this case, a
warning message as described in the
Complex Patterns section is displayed.
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About Color Propagation
The Rectangular Pattern
command does not propagate the UDF's color to the pattern.
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Patterning Bodies
The application patterns the body's geometry without taking into account
the body's polarity. However, if then you insert the pattern obtained in
another body, then the application takes the polarity of this body into
account. This explains why patterned bodies are not visible if they are
inserted in negative bodies.
In the following example, the user pattern points to Body.2 included in
Body.3 which is a positive body. In this case, the pattern is visible in
the geometry area because the pattern's result is added to existing
geometry.

If Body.3 is changed into a negative body (the Add feature was changed
into a Remove feature), then the user pattern is no longer visible
because the pattern's result is subtracted from existing geometry.

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Keep Specifications
Selecting the Keep specifications option creates instances
with the limit Up to Next ( Up to Last, Up to
Plane or Up to Surface) defined for the original
feature. In the example below, the limit defined for the pad, i.e. the
Up to surface limit, applies to all instances. As the
limiting surface is not planar, the instances have different lengths.
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In our scenario above, as the pocket's height is specified,
activating the Keep specifications option is
meaningless.The Keep specifications option is not
available if you are patterning a pattern.
In case you create a pocket and a hole that are overlapping
each other and pattern it by selecting the hole as the
Object to Pattern: |
- Selecting the Keep specifications option
creates the pattern as shown:

- Clearing the Keep specifications option
creates the pattern as shown:

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In case you have created two overlapping pockets and pattern the pocket,
you get the complete circular profile that is independent of the
Keep specifications
option. |