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3D Model Articulated Parts
Posted: 18 May 2009 06:03 AM  
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Hi,

I am looking for some clarification in the way in which artciaulted parts are defined in a CDB compliant 3D Model.

If we can take for an example an aircraft, then my current understanding is that the model will be split into a number of zones, including for example Elevators. Each zone may contain a single DoF as well as a group node.

Some queries about how this works, particularly when linked in with a runtime….

1. A typical aircraft will have two Elevators. Given that the zone name is stored as XML within the comment field would both elevators have the same zone name, or do we append a number to the end of the zone name (e.g Elevator1 & Elevator2)?

2. If we do append a number then is there a standard for the order? E.g in DIS I believe we would work left->right and forward->back if parts need to be further resolved.

3. If we don’t append a number, or if there is no standard for these numbers, then how does the runtime know which is the left elevator and which is the right elevator?


Thanks for any thoughts you can provide, and am happy to be pointed at part of the CDB spec if this information already exists.

Cheers,
Andy Stannard.

 
Posted: 16 October 2009 04:15 PM   [ # 1 ]  
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Joined  2008-06-12

Andy, your answer has been posted here in the form of an addendum called CDB Specification Addendum - 3D Model Node Numbering Scheme.

The short answer is: Sibling nodes with identical names are numbered from 1 to n using a pair of square brackets. The leftmost sibling is the one with the smaller XYZ coordinate.

Cheers,

Bernard

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Bernard Leclerc, Eng.
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