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Did You Know? PTC Creo 3.0 Enhancements: Chordal Rounds

5-Regular Member

Did You Know? PTC Creo 3.0 Enhancements: Chordal Rounds

One major enhancement in PTC Creo 3.0 has been the addition of chordal or constant width rounds. This new round option allows the creation of more aesthetically pleasing geometry by maintaining a constant width along the whole of the round length and eliminates the tedious process of having to construct round geometry using surfacing techniques. Users have the options of using circular, conic and C2 continuous rounds.


Paul Sagar, Director of Product Management, gives us an introductory overview of how you can use these new features:


In PTC Creo 3.0, we’ve added the chordal, or constant width round, option to give you an easy way to maintain constant widths for the entire length of the round.


In this example, we’ve applied  a round to the edge of the model. The transitions at the ends of the rounds blend toward a triangular patch. With chordal rounds functionality, this can be changed.


Inside the round user interface, click “Chordal.”


Then, when changing the value of the round you can see that the round maintains its constant width.


DYK_chordal rounds_image 1.png
Within the round user interface, click “Chordal” and you will see the round maintain a constant width.


In the next example, we will add another round to a transition which blends to a 3-sided patch or point.


Again, in the round user interface click “Chordal” results in a constant width round.


DYK_Chordal_Round_Image 2.png
An example of a constant width round formed from the transition of a 3 side point


From here, you could also select C2 continuous to change this round to curvature continuous. Changing the shape factor will alter the cross sectional shape of the round.


You can apply a reflection analysis onto the geometry by clicking “Analysis Reflection.” From here, you can see how cleanly the reflection lines transition across the patch structure.


DYK_Chordal_Round_Image 3.png
A look at the reflection lines across the patch structure using “Analysis Reflection”



You can also see clean reflections and highlights on the model by clicking “Shading with reflections.”

Check out our video tutorial on the PTC University Learning Exchange (“Chordal Rounds”) to learn more.

Stay tuned to our “Did You Know” blog series as we cover all of the exciting, new enhancements in PTC Creo 3.0.


For more in-depth product feature explanations, visit our Tech Tips area.


Have some ideas about what PTC Creo product features you’d like to learn more about? Send me a message or leave a comment below and we’ll write up the best ideas from the community. Thanks for reading, looking forward to all of your feedback!

This thread is inactive and closed by the PTC Community Management Team. If you would like to provide a reply and re-open this thread, please notify the moderator and reference the thread. You may also use "Start a topic" button to ask a new question. Please be sure to include what version of the PTC product you are using so another community member knowledgeable about your version may be able to assist.

Can someone please advise....any rounds created prior to Creo 3 do not seem to have the ability to utilize the Chordal enhancement (the click button is grayed out for legacy rounds).  Is Creo 3 working to product specifications here, or do I have an alternative solution to get my old rounds communicating nicely with the new programming?  Other than re-creating all of the rounds in Creo 3?  Thank you in advance for your feedback.