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How to create a point under a coordinate system?

Siemens Creator Siemens Creator
Siemens Creator

Hello,

 

This must be very elementary, but how can I create a point under a coordinate system?

 

My goal is to have a point that remains at the same position relative to a coordinate system, even when the coordinate system is relocated (translated and/or rotated).

 

For example, suppose there is some pre-existing CSYS.

I want to create a point relative to this CSYS.

When I move the CSYS around, I want the point to accompany it.

 

Currenlty, I can only create points that remain at their original locations and don't follow the relocation of the CSYS.

 

Note 1:

I can use "Set WCS to Datum CSYS", but that only works at creation time, there is no persistent associativity between the point and CSYS.

 

Note 2:

During the creation of the point, I can select "Existing Point" and then click on the origin of the CSYS. This will create the desired associativity between point and CSYS, but it only works when the point coordinates relative to CSYS are (0,0,0).

 

Thanks,

Marcio Tokita

11 REPLIES

Re: How to create a point under a coordinate system?

Siemens Honored Contributor Siemens Honored Contributor
Siemens Honored Contributor
Expand the Settings block of the point dialog - do you have Associate checked?

Ben

Re: How to create a point under a coordinate system?

Siemens Creator Siemens Creator
Siemens Creator
Ben,
Interesting.

Yes, Associative is checked at creation time. But:
1) I also get a warning saying "a fixed point will be created", which I am not what it means.
2) Once created, I double-click on the new point and there is no Settings nor "Associative" anymore.
3) The point becomes of the type "Inferred", and its Details pane is empty.

Furthermore, if I reposition the (supposedly) parent CSYS, the point just remains at the same absolute coordinates, meaning that there is no associativity.

Marcio

Re: How to create a point under a coordinate system?

Siemens Honored Contributor Siemens Honored Contributor
Siemens Honored Contributor
Are you creating a point offset from the existing point, or is it at the same location?

If it's at the same location, don't change the "Reference" to WCS - this will give you the alert regarding the fixed point. Leave the dialog at the default settings and just make sure you pick the existing point of the Datum CSYS and you should get your result.

Re: How to create a point under a coordinate system?

Siemens Phenom Siemens Phenom
Siemens Phenom

Do you actually need an additional point at the origin of a CSYS object?  I ask because a CSYS object already includes a 'point' object that always moves with the CSYS object.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA

Re: How to create a point under a coordinate system?

Siemens Creator Siemens Creator
Siemens Creator

BenBroad,

 

Right. If I pick the origin of the CSYS for the new point, then it works as expected: the point follows the CSYS when the latter is relocated. But I need to create several other points at different locations. I need them all to move with the CSYS.

In sum, I need the point coordinates to always be with respect to the CSYS. This way, when I move the CSYS, the points would come along.

Re: How to create a point under a coordinate system?

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

When you create a point, you can use the "inferred point" type option, keep the reference to absolute, change the offset option to rectangular (or one of the other options if it is more convenient), and create points offset from the point object in the datum csys. These points will keep their relative offset to the datum csys point if/when the datum csys moves.

 

Alternately, if the points you are creating lie on the same plane, you can create a sketch using the datum csys as reference and create all the point objects in the sketch. If the sketch only references the datum csys for positioning, it will move when the datum csys moves.

 

Edit: Even if the points don't all lie on the same plane, you can still use the sketch technique, but it may take more than one sketch to define all the points.

Re: How to create a point under a coordinate system?

Siemens Creator Siemens Creator
Siemens Creator
JohnRBaker,

I come from the CATIA world, so I may have basic concepts missing or wrong.
I simply need a constellation of points that would follow the CSYS.

The application is this:
I have a CSYS somewhere in a part. The location and orientation of this CSYS determines where to add other pieces of geometry, such as points, lines, tubes, spheres, sketches, swept, etc. If points were correctly associated to the CSYS, everything would automatically follow the CSYS when it is relocated.

Currently, the "base" CSYS' location and orientation are parameterized off of an excel file. If I change the values stored in the excel file and sync the parameters, the CSYS correctly relocates itself. I just need these "children" points to follow it.

Marcio

Re: How to create a point under a coordinate system?

Siemens Phenom Siemens Phenom
Siemens Phenom

Since I no longer have access to NX, I can't verify this, but if I recall correctly, there's an option that allows you, when creating a point, to optionally select an existing CSYS as an associative and positional reference.  Perhaps someone could look into this and report what they find.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA

Re: How to create a point under a coordinate system?

Siemens Creator Siemens Creator
Siemens Creator
cowski1,

Following your recommendation, I chose the following:

Type=Inferred
Location=pick origin of CSYS
Reference=Absolute
Offset=Rectangular
Delta=(0,100,100)
Associative=ON
This created a point that follows the translation of the CSYS!

It does not follow its rotation, tough. Is there any other setting such as this that would also associate the points to the CSYS with respect to rotation?

Marcio