×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Unsolvable constraints on contextual parts

Unsolvable constraints on contextual parts

Unsolvable constraints on contextual parts

(OP)

I am having a problem with constraints attached between a contextual and non-contextual part.  Basically, I know what the problem is, in layman's terms.  However, I don't know whether it should be considered a bug, and I cannot seem to fix it in a way that makes good design sense.

What is happening:  a constraint (contact, offset, etc) is placed between the contextual and non-contextual parts.  If this is the only constraint, update functions perfectly.  However, to constrain all degrees of freedom, this is not sufficient.  The next constraint that is attached will not update.  The explanation is relatively straightforward:  the contextual part has no constraints, (obviously) so the addition of constraints on a subsequent part, which rely on the location of the contextual part, are causing a confusion as to where the constraint update occurs.  Proof:  Adding a fix constraint to the contextual part causes all constraint updates to function as normal.  However, the addition of a fix constraint causes other problems.

What is the answer to this riddle?  Is this a bug?  Or is this designed-in logic?

Thank you.

-----------------------------------------------------------
Catia Design|Catia Design News|Catia V5 blog

RE: Unsolvable constraints on contextual parts

I have tried to reproduce your problem (as I understood it to be)in SP4.
New product with 3 parts:
1 Single (no links)
1 Parent (no links)
1 Child (contextual link to P)

Constraints behaviour :
S-P
normal updates, P drives C as expected

S-C
normal updates, apart for the constraint that interferes with the link - this  will not update ( as C cannot drive P as expected)- and the link takes precedence

C-P
normal updates, again apart from the one that interferes with the link, as above


So I think it's a bug...

RE: Unsolvable constraints on contextual parts

I thought all contextual parts should be fixed, to maintain the same position as the parent and skeleton parts.

(or use an axis-axis coincidence constraint on contextual parts)

why does the fix constraint cause other problems?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources