Multibody – Another look at patterning bodies with Creo 11 and higher

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Welcome to Blog Post #21 in Our Multibody Series!

In today’s post, we’re diving into a powerful new capability introduced in Creo 11—the ability to reference an existing point/coordinate system based pattern in a geometry pattern of type "point" pattern. This enhancement can significantly streamline your workflow, especially when working with complex body patterns.

To get started, check out the What’s New video linked below. The first section highlights the benefits of the new “From Pattern” option in point patterns, which helps accelerate regeneration using the “Identical” or “Flexible” regeneration modes. Around the 50-second mark, the video also demonstrates some useful body patterning techniques.

While the video covers the basics, here are a few key tips and tricks to help you get the most out of this feature:

1. Patterning Bodies with Coordinate Systems
   Use a pattern of coordinate systems to define both the position and orientation of each body pattern member precisely.
2. Using Curves for Placement of Coordinate Systems
   If your bodies lie on a plane, consider sketching a curve with points that define their future locations. Then, replicate a coordinate system along that curve using the “Follow the Curve” option. This approach makes it easy to align all coordinate systems—for example, pointing them inward.
3. Leverage the “From Pattern” Option
   When creating a Point Pattern, use the new “From Pattern” option to inherit the structure of an existing pattern.
4. Set the Alternate Origin
   When defining the body pattern, be sure to select the first coordinate system as the alternate origin for the lead pattern member. This step ensures the correct orientation relationship is maintained during replication.
5. Merging Patterned Bodies
   When merging patterned bodies, always select the body pattern feature in the Modifying Bodies collector of the Boolean Merge feature. This ensures the model updates parametrically if the number of bodies in the pattern changes.

Thanks for reading.  I hope it was informative.

If you liked it, give it a Kudo.

Back to Creo Multibody Home: Start Here!

Enjoy!....Martin

[S_Edgenear]

@mneumueller 

Hello Martin,

About point 1) Patterning Bodies with Coordinate Systems, may I suggest a further improvement?

Currently, to be able to pattern using Coordinate Systems, we have a few options:

a) Use a 2D sketch and place on a plane several 2D coordinate system, that uppon exit are converted to 3D coordinate systems, with all having the same Z plane and Z normal as the sketch. Good for 2D work.

b) Create a single Coordinate System, and use a Table Pattern if the user wants to change the origin, Z level, or orientation. Then he can pattern the body using this table pattern to "force" the bodies copies to align to those patterned coordinate systems. This allows to vary the Z level of the coordinate systems, or using non uniform or regular values, difficult to describe with other pattern types (direction, axis, etc), but does not allow the additional coordinate systems to be parametrically attached to any existing geometry, unlike the 2D sketch positioned coordsys, which can be aligned to an edge, or positioned on the middle of an edge, or having orientations parallel to existing geometry. With table patterns, these geometric relations are difficult to describe.

c) Existing pattern of points on a curve with associated attached coordsys that follow the curve orientation. This allows 3D patterns of bodies, they do not have to lie on a single same Z plane, but allows selection of a single curve, and does not make easy to associate the coordys origin or orientation with existing geometry, except for the selected curve, wich is a single path, although could vary in 3D (not be on a single plane).

What I propse, is an additional way to be able to pattern bodies (or quilts):

d) Let the user click on a list of single coordsys, or on one (or several) 2D sketches which have 2D coordinate systems, or on one or several table patterns of coordsys. This allows the user to mix regular patterns, with table patterns generated by a table of origin values and angle orientations, with single coordys defined by geometric relations, or sketch 2D patterns of Coordsys on a single plane defined by geometric relations. This would allow to pattern bodies along complex coordsys orientations, on different planes, on different orientations, and would allow the user ro mostly avoid pattern tables to be able to vary 3D height or angles, and mostly control every csys orientations using only lists of single existing coordsys, or (or single coordsys embedded on the feature pattern), or mostly 2D sketches at several planes and orientations, where the user better parametrically associates the individual 2D coordsys origins and orientations to existing model geometry.

Currently the only way to copy a body to different individual existing coordsys (created using references to geometry) is with flexible modelling "Move" (with the "Create a Copy" option activated) with the "Constraints" method, using a "From" Csys "To" Csys (as if assembling the body to a new CSYS as if it was a part in asselby momde). The problem with this method is that it does not allow the user to leverege the "Reference Pattern" possibilities later downstream, if the user copies each body individually. If the bodies copies were "re-positioned" in a list of existing coordsys on the model (or newly on-the-fly individually created CSYS inside the pattern list of CSYS), then the user would be able to better select the better way to describe the position of each individual Body Csys, and the pattern tool besides copying the bodies to said CSys described location, would also let the software to know that this list is a pattern, even an irregular one, and if each body for instance has an hole to assemble a screw, the software would be able to reference pattern the positioning of said screw on all the bodies, regardless of location or orientation.

[mneumueller]

Replying to S_Edgenear

Hello Sergio,

yes, you have a good suggestion and it is in line with a backlog item that I had captured in the past as "Pattern recognition feature based on manually selected coordinate systems". 
This would give you a coordinate system pattern that could then be used as a basis for reference pattern, point pattern etc.

Thank you very much for your input confirming that idea.

[S_Edgenear]

Replying to mneumueller

Hello Martin,

Thank you for your feedback.

May I ask how you are thinking of implementing this capability?

"Pattern recognition feature based on manually selected coordinate systems"

A)

By the description of the possible future enhancement, it sounds as it may be implemented as an FMX feature. Currently it's the "module" that has the feature recognition tools, but currently they only work for 3D geometry, meaning, it only recognlizes faces. It would be nice to also recognize 2D geometry, for example, imported points, imported CSYS, imported circles (to use the circles as center for holes, for instance), instead of having the user to use a sketch and manually "Use Edge" for all the circles on a sketch. But I digress.

I was asking, because even though it might make sense to use the list of picked existing CSYS as a way to generate a pattern (using the flexible modeling approach), I also think that one another way to implement this, is to create a Datum feature with multiple CSYS, similar to a Datum point feature, which can have multiple points defined inside a single feature.

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The implementation of the Datum Point feature is split with two distinct ways to specify points:

a) Regular "Datum Point", feature which defines a single one, or a list of multiple points defined by geometric references.

b) "Offset Coordinate System" datum points, which are defined as a table of X, Y, Z values to offset from a single referenced Coordsys.

c) Although it does not exist, it would be nice to mix the two methods of point definition, from references, or from offsets from a specified coordsys, where the user would use the most convenient method to specify the points, but producing a single point list to be used for patterning. Currently, the user has to select one of the previous two methods.

B)

For multiple "Datum Coordsys" feature, my proposal would be to extend the interface for single Coordsys creation method, with buttons to "Add" and "Remove" (or reorder) additional Coordsys, similar to the "Datum Point" creation method.

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C) A third option, would be that instead of having a pre-defined feature with a list of several Datum CSys as described in point b), to use latter in a pattern (to pattern bodies, for instance), would be to allow both the selection of multiple CSYS on the patterning feature, and also, as an alternative, to on-the flyr creation of several regular CSYS to embed in the pattern feature, as we can embed datum points, datum planes, etc, in regular features (like in extrude).

I think one of these 3 methods has pros and cons, I was thinkng the easiest way for PTC to implement to have the least disruption to existing workflows, but also balancing the usefullness of not creating unecessary restrictions If one chooses the most complex implementation, we have to wait longer. If the most simple is selected, maybe will persist some restrictions.

Sorrry for the long rant, and once again, thank you for your valuable feedback.

Sérgio.

[mneumueller]

Hi Sergio,

this will need to be determined once we actually get to the project. But you are right that there are several ways to go.