Would like to do negative distance constraints in a catia sketch

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1

Hello

In the sketch mode of catia, the distance constraint has the same logo as the offset constraint of assembly and I thought I would get back to my habits of the offset constraint. However, there is, it seems to me, a big difference that bothers me for what I want to do. It would seem that the distance constraint in a catia sketch cannot be negative. Now, to define the position of certain points in relation to the sketch coordinate system, I would sometimes like to use negative distance constraints.

1) Is it possible to define negative distance constraints in a catia sketch?

2) If this is not possible, do you have a workaround?

Thank you in advance for your help.

2

Hello:

1 ) No, it is not possible to define a negative constraint in the sketch.

2 ) We use a formula that calculates the absolute value of a (negative) parameter:

abs(my parameter)

 

3

I see.

On the other hand, it bothers me a lot because sometimes I have parameters that have values that vary between positive and negative values. So if I set an absolute value, the parameter associated with my distance constraint will be positive and that's not necessarily what I want.

4

OK

I correct:

The user parameter of type length will take the value you want (positive, negative).

The associated sketch by formula (calculation of the absolute value) will always be positive.

If what you're trying to do is to see the starting point of the line evolve (in my example) as a function of a value varying from -n to + n.

You have to go through an external reference (a plane for example), this plane is associated with the user parameter and in the sketch you create a coincidence  of the end of the line on this plane.

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